Trouble Free H.F. Hertz Antenna for the Apartment Dwelling Ham

Simple and Problem Free Hertz Antenna Technique

for the

Apartment Dwelling

High Frequency Ham Radio Operator

 

Field Day 2018

S.K.C.C: 32BC

 

In any system, the correct design solution is one which comprehends and then best balances every one of the requirements.

Rounded Corners 05

When it comes to a high frequency ham station, the antenna alternative chosen by most apartment dwellers is no antenna at all. The design here is a wisp of an antenna that bothers no one and which can work Japan, Australia, France, European and Asian Russia, the Caribbean, Central America, Polynesia and South America from the Pacific coast of Canada. It is a simple solution for apartment dwellers, it is a cheap solution and it causes no t.v.i. or other r.f. problems. It is far preferable to the alternative selected by so many fellow apartment dwellers: no antenna at all.

Let’s Plunge Right In

Too many ham radio operators today don’t have a feel for what they are doing with r.f. They are wed­ded to the idea of the unbalanced feed. Worse, they end up wrestling with the counterpoise, the “ground”, complications implied by the Marconi antenna. At the very least they seem to be resigned to fighting the “antenna currents” that an unbalanced feed necessarily produces on a coaxial cable.

Let’s start out by first dealing with the usual Marconi and Hertz antenna installations; let’s put an end to r.f. all over the house and in the neighbours’ houses, too.

Marconi

An implication that it seems to be impossible to rid from the minds of fellows using a Marconi antenna is that they are not just pumping 100 watts of r.f. into their antenna but that they are also pumping that same 100 watts of r.f. into their ground, that is to say the building’s wiring, the safety ground wiring. R.f. in the safety ground is well coupled into the power and neutral conductors of a residence and, in North American code, is even hard connected to the neutral line at the service entrance. The house wiring becomes part of the antenna system.

The ground wiring and everything connected to it is every bit as much a part of the antenna as is the live element. Both radiate just the same amount of r.f. power, fellows. The ground wiring  along with every electrical power consumer in the building is worked against the live element. Thinking of what is connected to ground in your house is thinking about one side of your antenna. It’s not just appliances that get the “benefit” of r.f. The land line telephone system, the cable television system, the garage door opener, the security lights and…you name it. They are all “feeling” that 100W of r.f. With regard to r.f., there is no distinction whatsoever to be made between “hot” and “ground”.

 


 

With regard to r.f., there is no distinction whatsoever to be made between “hot” and “ground”.

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You know the reason why vertical antennas have gained a reputation for being noisy on receive now, too. Most verticals are Marconi antennas. Both the safety ground and the neutral serve all the houses in the neighbourhood. The receiver is wired into the electrical appliances of the entire neighbourhood.

That water pipe “ground” down in the basement is not a magical, mysterious, ghoul that somehow slurps up and tidily disposes of every drop of r.f!

Connecting 100 watts of r.f. to ground does not make 100 watts of r.f. somehow “go away” leaving r.f. only on the driven element. That reticulation of wires beneath the lawn out there in the back yard under the vertical does not make 100 watts of r.f. “go away” and it does not suck all the 100 watts of r.f. away from the transmitter and the building’s ground and other wiring. Not a femotowatt of r.f. connected to ground “goes away”.

If that concept of connecting the transmitter’s 100 watt output to the building’s wiring could be driven into the heads of such fellows, the “mysterious” interference problems they have all over their house and probably the houses of their neighbours would make sense to them instantly. The “artificial ground”, simply a loading coil or a ferrite in the counterpoise, is not a problem free solution. It’s a trap or choke of sorts in one antenna leg.

The all too common issue of r.f. in the microphone circuit is an ideal illustration of r.f. in “ground”. The microphone is not receiving radiations from the antenna out there in the back yard, guys. The “antenna” isn’t too close to the station, either; the microphone is the antenna! R.f. is in the microphone element because the microphone has been made part of the antenna circuit. That’s the reason. It’s one side of the antenna system. The station is alive with r.f. since all of the station’s equipment is connected to one side of the transmitter’s 100 watts of output.

“Experts” extol a good ground because they once read about that in a book. All that a “good ground” does in a Marconi installation is to spread that r.f. around thinly. Spreading r.f. around thinly is fine. That’s a great idea. The live element sees that ground and the two of them, live element and ground element, together, set up between them the electric and magnetic fields to be radiated. Fine.

(We have to stop off for a moment: readers have misunderstood the expression “experts” here. There are experts, you see, and then there are “experts”. Experts know what they are doing, that’s to say engineers, technicians of long experience and hams of long experience. Their fundamental approach includes a willingness to read and to read more and otherwise to learn. “Experts” are those who are content with scattered fragments of information (acquisition of anything more would be work), who are ill informed or who are outright misinformed and who are content to be so. They nonetheless impose themselves aggressively on newcomers. To enthral the wide eyed acolytes in their train they impart a defective orthodoxy.)

Just fine an arrangement though a Marconi antenna is and however thinly spread the r.f. may be, nonetheless 100 watts of r.f. is 100 watts of r.f.; that’s a good slug of energy. It doesn’t disappear somewhere, you know. It does not conveniently evaporate never to be seen again. That 100 watts of r.f. can’t be put out of mind simply because one of the things that it was connected to was a green wire. It’s still with you, fellows. It’s all around your station; it is your station. In a Marconi installation, all that equipment that you are sitting there looking at is one side of your antenna.

All that r.f. flowing about has voltage nodes on it just as certainly as it would have out on an antenna leg. Your neighbour’s home theatre amplifier was designed by Cheapo Engineering and put into a plastic cabinet. It is consumer equipment and that’s how it has to be designed and built if it is to compete in the consumer market. If it is at or near a voltage node for the wavelength of your 80 metre evening fone net then, when you check in, your neighbour will be entertained to Donald Duck noises!

Give a thought to 100 watts of r.f. popping around in building “ground”. Truly, it’s not a complicated idea, fellows.

Hertz

In the case of users of Hertz antennas fed by coaxial cable, r.f currents on the outer surface of the shield braid of the feed line are inevitable in practical terms and must be dealt with. Eliminating them can be a chore and, in the general case, will not be entirely successful meaning that r.f. ends up back in station where it is very much un­wanted. It is conducted off to the same “ground” and ends up both coupled and hard connected into the house wiring. That is to say r.f. is connected to every power line connected device in the building, exactly where it is not wanted. The antenna’s live element and the building’s wiring are worked against each other though there’s far less r.f. in “ground” than in the Marconi case where the connection is explicit. By definition, the receiver gets the same treatment.

At the very least, the outer surface of the shield braid is a conductor in the near field of the antenna. An imposing installation of balun, chokes and ferrite up at the feed point will not alter the fact. The outside of the shield has r.f., common mode r.f., on it from that fact alone. As well, there may be leakage of r.f. from the inside surface of the shield at the feed point, r.f. intended for the counterpoise side of the antenna however elaborate the arrangements up there. There’s a small amount of leakage through the braid, too.

Forget the pure case discussed in books: the outside surface of a coaxial cable feeding the antenna at a ham’s radio station is not pristine, it’s an r.f. jungle.

The outside surface of the braid, since it is not usually decoupled in the station, is a projection of “ground”. It is part of the antenna system, then, and no mistake. Even decoupled at both ends, it’s an “antenna element”. Antenna patterns are not our business here so we won’t go into the matter more than to point out the fact.

The Ineffable Glory of Coaxial Cable

Those embracing and blindly in love with coaxial cable, please, stop off for a moment and give a little thought to the magnetic and electric field realities.

Good quality braid leaks. Period. Cheap braid leaks even more. Is your coax double shielded with silver plated copper braid? Are you spending $11.50 per metre, $3.50 a foot for it? No? Ok, so it leaks r.f. Is there some reason that professional station installations, duplexers and so on, use such high spec. cable? Yes, there is.

Do you think that there is no coupling between the r.f. flowing within your inexpensive coaxial cable and nearby conductors? Does running your coaxial cable along a conducting surface, say strapping it all the way up the tower leg, not change its characteristic impedance? How about burying it in wet soil? And, ahh, how about lumping it together tightly with several other such cables, putting the lot into a steel conduit and then extending that assemblage all the way up to the roof of a building? Do you think that there is no change in the characteristics of such cables and no coupling between their inner conductors?

Have a look at this fine little document. It is a great starting point, it’s a succinct analysis. As ever in engineering discussions, it must deal with the pure case, particularly it must posit that the currents within the coaxial cable are exactly balanced. That’s asking a great deal of a practical radio installation, especially of a ham radio operator’s installation with it’s varying wavelengths. When reading that item, consider the case where the magnetic fields are not balanced; copper braid on its own is not going to produce magnetic shielding.

The world from which the ham’s cable emerges and the one into which it is placed into service are not at all pure cases.

Follow on with this item. Here’s an ancient, succinct little paper that the A.R.R.L. put out. It’s old, yes, and there must be newer ones around. These guys had their feet on the ground, though, and Maxwell’s ideas still work just as well today as they did away back in 1981. The fellows made empirical observations. This happened to come to hand at once when preparing this paragraph. Have a look around the web, you may find other examinations of coax more to your taste. Papers like this will ease into the mind of the coaxial cable worshipper that there really is no magic in coaxial cable.

Coaxial cable is simply a method of moving r.f. It is not the method of moving r.f. There’s no magic in coax, not a bit.

Open wire has worked well for nigh on a century.

The great ocean spanning point to point shore stations and ship to shore stations of the last century almost always used open wire feed. Sometimes it was 600 ohm and sometimes 1,200 ohm but it was open wire feed that was the choice. Read about those stations. Were the design engineers for those stations wrong? Were they cheaping out on coaxial cable? No. The fact is that open wire feed was the right way to move r.f. out to the vast antenna farms that such stations had. It was a proper, logical, engineering decision for the demands such stations imposed on antennas and, so, on feed lines.

No R.F. in “Ground”

This radio station, located four stories above grade and in a wooden building full of apartments would be a worst case for r.f. in “ground”. This station has no r.f. in the station. It has no r.f. in “ground”.

The station has no interference issues. The Building Manager, the Building Superintendent and the administrator for this building’s cablevision have been aware of the station from the beginning. There has not been a single complaint of t.v.i. or any other complaint about the station. That’s a clean record extending back to 2006.

There are no red faced, spluttering tenants hammering on the door of this station!

At this station, all the r.f. produced by the transmitter makes its appearance out on the an­tenna. The radio station’s r.f. is not referenced to station ground. Station ground “knows nothing” about the r.f. being generated.


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Station ground “knows nothing” about the r.f. being generated.

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The r.f. produced within the transmitter is sealed within the Faraday cage that is formed by the transmitter cabinet and the tuner cabinet and the braid and “N” connectors of the high quality coaxial jumper joining those enclosures.

The “live” element of the antenna is worked exclusively against the other element of the antenna. In fact, there is no “live” element and counterpoise. Each element is the counterpoise of the other; each element only “sees” the other element. Neither element is at r.f. “ground” potential. Neither element “sees” the building ground or any other building wiring any differently from the other element.

There is no r.f. in the shack. Every watt of r.f. produced by the transmitter appears only out on the an­tenna legs. Whatever attenuated r.f. makes it’s way into the building from the antenna is all common mode for every power, neutral and ground conductor in the building. It’s common mode for the feed. The same applies, of course, to all the other wiring and in an apartment building there is a plethora of such circuitry because of fire alarm, cable television, telephone and intercom equipment along with the tenants’ television receivers, audio equipment and Ethernet cable runs.

20150308  Say, ahh, Speaking of Ground…

Let’s take a short excursion down a side road here since we have the time to do that. We will come back again to the balanced antenna promptly.

Just where is “ground”, by the way? There is a constant irritation here. It’s from those immensely important “experts” who pontificate in measured tones, using a suitably deep, authoritative, voice; to wide-eyed newcomers in the ham community about the importance of the newcomer’s antenna being at the correct “elevation above ground”.

Those readers who have the idea that somehow “ground” is the surface of the lawn beneath their dipole or sloper are as green as their grass. If a such a state of affairs existed, then ground penetrating radar would be a myth. Unless you live in a salt marsh or on top of a rich ore body, then not only is “ground” not at the surface but the whole idea of “ground”, at our h.f. wavelengths, is very fuzzy. That’s very fuzzy.

If you want a reflector at the level of your lawn, radio operator, then put in a reflector at the level of your lawn.

It’s not a complicated idea and, for a Hertz antenna, it does not mean putting in a vast mesh of wires. Put up your dipole and, beneath it, right on the lawn, drop a reflector along the line of the antenna. The wire is a “mirror” for your signal.

The presence of a wire on the grass is also a great reason for not wasting valuable operating time mowing the lawn. A rank lawn and an unpainted fence are the traditional hallmarks of a ham’s residence; preserve a noble tradition!

If there’s a woman around to complain, then slit the turf first and then drop in a wire. If you use magnet wire, heh, with magnet wire’s bonded insulation you won’t poison the lawn. There will be no resistance losses from surface corrosion, either. Yes, and the wire will never have to be replaced because of corroding out. You can do the same along the legs of your sloper. In both cases, you want a length of wire a bit longer than the driven element, say five percent longer than the driven element. Sound familiar? It should: it’s what Mr. Uda and Mr. Yagi described so long ago.

Send more of your 80 metre or 40 metre, er, meter, or even your 20 metre signal upwards to the ionized layers and let it spread around up there. Let it rain down from 200kM up. It would be great to get the spacing and length just right but, if that is not practical, something is better than nothing; just don’t make the reflector shorter than the driven element.

The alternative, no reflector, warms up minutely the soils under your property with that r.f. instead of having that r.f. up in the sky. If you want to be fancy, put in three wires along the run of your antenna, spread them out a bit; it’s sure not a big job. Three lengths of magnet wire will still cost zilch and make a better “mirror” for your driven element than dirt, gravel and old water and sewer pipes with their rusty, lossy surfaces.

Without an explicit reflector like that, the signal heading down into the ground will be largely dissipated. Such returns as you do get from soil and gravel horizons will be diffuse in their arrival back up at the driven element.

Put in a reflector: nothing fancy, just a piece of wire.

Be suspicious of “experts”. Do your own thinking.

Ok, back to the balanced antenna…

Abandon Coaxial Cable

Back out onto the main route, now: the design of a station in which there is no issue of r.f. referenced to “ground” and no “antenna cur­rents” on coaxial cable is not complicated. It’s unusual these days but it’s not complicated.

A number of these magnet wire antennas with a balanced feed has been put up over the years. Local noise has been the big problem here among frame apartment buildings. With this version either the local noise had gone down, quite possible with the endless comings and goings of the tenants in the 150 apartments in the near vicinity, or the bands have improved a bit. Either way, this antenna version has become the most successful. The subsequent arrival this summer [2015] of the superb quadruple conversion receiver in the TS-930S with its sophisticated 100kc final i.f. has made a further improvement of 1.5 to 2dB on 80M in the evenings.

Balanced Output

Central to a proper design is transforming the unbalanced output that all commercial transmitters today provide into a balanced output. In the case of this station, that transformation is achieved within an ancient and honourable Johnson Viking “Match Box”.

The Match Box was purchased at a ham radio flea market thirty odd years ago. It was opened up and, sadly, an “expert” had been at work in it. It appeared that an attempt had been made to modify it for use in tuning a wire. That made little sense since the device was designed to do that by adding a strap option. The old girl was put back the way the Johnson engineers had intended.

The “expert” had also known that it hadn’t been necessary to put all of the nearly two dozen pesky cabinet screws back in; he announced his inexperience, loudly, right there!

The Match Box uses a truly balanced output. Today’s antenna tuners tend to be of the balun type. The writer is suspicious of balun transformation because of the limitations imposed by the core’s characteristics. Much is asked of the core, particularly when compelled to work over such a broad frequency range. Naturally, for business reasons, the core in a commercial tuner has to be small, on the margin of the spec. The reader is urged to search out a trans­former, “link coupled”, type of tuner or to whip up his own antenna tuner using a proper r.f. transformer arrangement.

The core of the toroidal transformer operating at r.f. has another vulnerability: temperature. It’s not impossible that a used tuner has had its toroidal core heated to a point where its characteristics have changed. If the design of the core had been marginal in the first place, there may be added problems now since the permeability may have decreased from a previous user’s overheating of the core.

If you use a commercial balun tuner and have r.f. problems in the shack or have r.f.i. complaints, the balun is almost certainly the source of them. After a c.w. qso, check for warmth inside the tuner. If the core is good and warm, you don’t want that balun. The conductors are carrying too much current, that is to say they are too small, or the core is being driven to saturation or maybe both. A core bordering on or going into outright saturation is an invitation to nonlinear operation and that’s a route to radiating unwanted products. Go to a straightforward link coupled tuner with big conductors forming large cross section, high Q inductors and wired as a genuine transformer type of balanced tuner. Such genuine link coupled balanced output tuners are a staple at ham flea markets.

R.F. Hygiene

When building yourself, remember the old adage that if the enclosure is water tight it will be r.f. tight. You don’t want r.f. out flowing around on the outside of your cabinet. Make a clean machine. The Johnson Viking Match Box has 22 screws securing the cabinet panels: the Johnson engineers so many years ago knew their business.

You want the station “sanitary” with regard to r.f.; you are fabricating a Faraday cage. Secure panels tightly and with lots of hardware. Grower washers and star washers are cheap; use them.

Before proceeding into the following details, the reader must understand that a system, any system, is correctly designed when it balances all requirements. Much of what a fellow sitting in a cubicle does while wrestling with a systems design is exactly that balancing out.

Nuts and Bolts

In the present case, that is to say a station to be operated in an apartment building, it is required to have an antenna that is “invisible”. Now it’s not possible to achieve that literally but at least the antenna should be so inconsiderable that there will be no complaints from neighbours about having to look at it. The antenna here is made of #26 A.W.G. wire. That’s wire that is 0.40mm, 0.016 of an inch, in diameter. Four stories up, it’s difficult to see the antenna and that’s even when knowing where to look for it. Part of the antenna’s run is through trees and in among the tree branches it pretty much is invisible. It does not annoy neighbours by casting a shadow; there is no shadow.

 Wire Thickness, Close

Wire Thickness, Very Close

Adds Ten Percent, 640

The Man’s a Nut!

The instant reaction to hearing about antenna wire that is only 0.40mm in diameter is: “That can’t possibly work; the man’s a nut! If nothing else, just think about skin effect. ‘I squared R’ is going to eat up every watt of r.f. He’s kidding himself: all he’s got there is a dummy load.” Of course there is that obvious objection but how bad can an antenna be when stations all over North America can be heard and worked? Whatever the losses are to skin effect, they sure are not crippling. 8J1ITU was worked on the antenna’s second day up. That’s Japan on 0.40mm wire. A 100W fone station down in Argentina has been worked [2016] through contest QRM. Band conditions are not the greatest right now [mid 2014] and so that’s pretty good; this is an “apartment antenna”, not the aluminium overcast demanded by the ravening dx operator.

Of course, one can work Japan on five watts with the bands open but with stations responding at once to a call, consistent reporting of strong signals, no complaints of drop outs, 50 stations worked on only a part of Field Day [see addendum] and consistent good results on the regional evening fone net, this antenna does a great job.

The most distant of the control stations for the regional 80 metre evening net is 421km, 262 miles ( VOACAP computation) away and is heard and worked normally, that’s with no retries or relays. That’s under the present poor conditions and that’s on fone, note. The skeptic is invited to check the B.C. Public Service Net’s logs.

Other control stations hear the signals just fine and without retries.


 

Tuning is sharp, it’s hard to see and it works.

Formalism is left to others.

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The correct design solution is one which comprehends all requirements. Keep that concept firmly in mind not only with regard to wire only 0.40mm in diameter but all through this discussion. The alternat­ive chosen by most apartment dwellers is no antenna at all. This design is better than that design of no antenna! The design here is an antenna that bothers no one and which can still work Japan, France, Australia and Argentina when the bands are less than hot.

Another Digression, Bemusement

At this writing, five months after this latest magnet wire antenna went up, a third individual has now asserted to the author that such antennas are, of course, impractical from first principles: the thin wire means that they will keep falling down. Oh; has any of these three “experts” been using such antennas? No! Oh; in fact have they ever used such an antenna? No. Do use your own brains, everybody.

Look at the price of spools of magnet wire on line. Even if one leg were somehow entirely lost, the cost of 20m or so of #26 wire is zilch.

We’ve now had a series of fall’s North West Coast storms marching through. The antenna is still up. Some months ago the trunk of a small ornamental tree was broken off and pushed onto the property. It’s now dead top hamper has been resting partly on one leg of the antenna making it taut. It’s been that way for three or four months. Even in these storms the wire still hasn’t broken. Use your own brains, everybody.

The tooth pick and hot glue open wire feed also has not fallen down. It hasn’t required any attention, either. No antenna at all is not the superior alternative.

At 20150928. Full disclosure. The feedline was snarled in a length of 2×4 that was being arranged for painting out on the balcony. That did cause one spreader to come loose from its wire. R.t.v. was immediately available so that was used to restore wire to spreader.

At 20141212. Heh-heh. Big, big wind storm yesterday evening, winds to 70kMh (over 40m.p.h.). Trees blown down in Vancouver. Thousands of people were still without electrical power in the morning. Three schools were closed all day. Tree branches and rubbish were all over the roads this morning. The antenna legs bounced and the balanced line flapped around and…this morning all was serene. #26 magnet wire and that hot glue and toothpick technology had ridden out the winds just fine.

At 20150830. Another big wind storm yesterday with gusts reported by a ham in the nearby Gulf Islands to have been three m.p.h. short of qualification as a minor hurricane. The electrical utility reported that 710K households were without power. 50k remain without power this morning. The author’s building was no exception being down for 11 hours. The station operated just fine on the battery bank.

It was high summer, not winter, so there were going to be no power failures. In accordance with the dictum of Murphy the inverter/charged combination had been disconnected and was in pieces for inspection and maintenance. It was hastily reassembled and connected to the battery bank.

Ah, so if the station were in operation then the #26 wire antenna wasn’t blown down. Yes, just so. This storm was in daylight so it was possible to follow closely the activity of the antenna wire. It appears that such fine wire is only a little affected by even the strongest gusts. What does set the wire dancing is the exaggerated motion of the supporting trees as they respond to gale force winds. If using trees as supports, don’t bowse up your wire tight, fellows. That would be fatal. Leave a reasonable catenary.

at 20160310 Winds to 100k.p.h. overnight, 120,000 without power; antenna still up.

at 20170524 Front went through yesterday afternoon and overnight. Power utility reports 184k customers, all regions, lost power. Both antenna legs still up.

Readers who have advised this ham that such wire is impractical, since it will keep breaking, are invited to reconsider their views.

A Chestnut

“Hi there, John. Gee, I haven’t seen you since last fall. What’s that you say…your antenna did not blow down over the winter? Oh; then it’s not big enough!”

Back on Topic, Stealth Feed

The stealth aspect of this balanced antenna design does not end with the actual antenna legs. The feed for such an antenna should also be difficult to see. That’s an issue because a balanced feed demands two wires and spreaders. Four or six or more wires would be better but two work fine. If you have the choice, use four wires for your feed. In that way, with reasonable dressing, effects from nearby objects will be balanced out. In the photographs below, you see the author’s old time, “low rent” solution for a two wire feed, a 180 degree twist in the feed line.

The way that that matter of a conspicuous feed has been handled at this station is by the construction of a 600 ohm balanced line using the same 0.40mm wire as is used in the antenna legs. The shafts of cylindrical tooth picks are the spreaders.

Such small wire implies a spacing of only 29mm; that makes for a ladder line that’s outright…what shall we say…um…how about “dainty”? It looks completely innocent and not at all “technical”. (To see any image at full size, click on it.)

Looking West, Cropped, 640Stealth feed: 600 ohm #26 A.W.G. magnet wire balanced line.

Suspension 01, 640Ty-Raps make ideal hangers. They can be adjusted in number and in size to accommodate the nearest spreader. The arrangement here damps motion in the ladder line. The Ty-Rap on the bracket is fixed, the others are a “chain” permitting the ladder line to respond without stress to the wind and to the occasional perching small bird. These black, ultra violet resistant, Ty-Raps do not become brittle in sunlight (a consideration even in Vancouver!)

Detail The #26 wire is held to the spreaders using dabs of hot glue.

A detail will be mentioned here. The first attempt at using hot glue to fabricate the ladder line was not satisfactory. The issue appeared to be a failure of adhesion both to the spreader and to the insulation of the magnet wire. The problem was corrected by the discovery that by heating the spreader and the wire with the hot tip of the glue gun before expressing the gob of glue, a perfectly solid joint resulted. The glue gun in use was tiny a dollar store item. The reader might have quicker results if he were able to lay hands on an industrial glue gun.

If you, too, use a small glue gun, pretend that you are soldering. Express a little glue onto the junction of the wire and spreader, just enough for thermal coupling. After a suitable preheating period, glue the joint.

Leakage

Don’t be spooked by old timers representing that leakage is an issue. We are using magnet wire here, not bare copper. The insulation rating of modern magnet wire will be on the order of 600 volts. Conductor to conductor, we are looking at an insulation rating of 1,200 volts. Leakage is not an issue.

20151217 Making the Ladder Line

Making a ladder line like this is trivial. It is quick, too. String one run of #26 magnet wire across the room at about shoulder height. In this case that was diagonally across the living room. One end was anchored to a shelf pillar and the other was anchored to a floor standing torchère lamp. Tension was maintained by having the lamp biased just a little off its base, pulled over a bit by the wire.

A second strand of wire was run right beside the first wire, not spaced, and connected at each end the same way. At 30cm, a foot or so, from one end of the two wires, the first spreader was inserted between the two wires. At the far end, again about 30cm or a foot or so from the anchor, the second spreader was inserted. With this technique, the first two spreaders are held tightly in position. The two wires then ran parallel to each other and spaced just right.

The remaining spreaders were inserted by measuring along the wires one hand span at a time and inserting a spreader.

If another run of this ladder line is made, room temperature vulcanizing silicon rubber will be tested. The hot glue seems to have become very hard over time. “Hard” may mean “brittle” so r.t.v. might be a better choice for the long term. As matters stand, though, the ladder line is still doing its job.

Ultraviolet light is energetic. It breaks the links in polymers itself and it creates nascent oxygen, too. If you decide to test r.t.v., you might like to use black r.t.v. Now the outer surface will be exposed to both agents, of course, but the black pigment might block penetration of the ultra violet radiation beyond the surface. If a reader with a suitable background in polymer chemistry can offer a more satisfactory but commonly available adhesive, that comment will be posted or incorporated right here along with attribution and thanks. A component of the proposed adhesive must not affect the magnet wire’s insulation.

The spreaders were made by clipping off the ends of cylindrical tooth picks. The side cutters or flush cutters from your electronics bench do a neat job on toothpick wood. For #26 wire, you want a spreader length of 29mm.

Place a convenient number of toothpicks side by side on your bench. Align the ends with a straight edge. While holding down the toothpicks with the straight edge placed on top of them, run a Sharpie along the toothpicks, twice, with a spacing of 29mm between the lines or as appropriate for your diameter of wire. Clip off the ends protruding beyond the Sharpie marks.

The very first, test, spreaders had notches made in them to accommodate the wire. Notch making was abandoned. The reasons were two. First, the tooth picks tended to split; common grocery store toothpicks proved to be made of very poor wood. The second reason was the discovery that using the wire stringing technique, above, that’s to say having good tension on both wires, the spreaders stayed in position just fine held there by the tension on the two wires combined with the early adhesion furnished by the cooling hot glue. The spreaders have tiny mass so it takes very little adhesion to hold them in place. If the two parallel wires are horizontal, the spreaders can simply be laid upon the wires and glued.

Those of you not operating within the confines of a little apartment will have the luxury of a shop and are invited to find better means.

Skin Effect

The use of magnet wire could be said to actually bring a benefit with regard to skin effect. The bare wire so often used by all radio station operators, not just ham operators, implies a corroded surface. A coastal climate much accelerates the process of corrosion of a copper surface. It is along that very surface that much of the r.f. current travels. Now with magnet wire the insulation is bonded to the copper’s surface and the insulation is transparent.

Those two facts, bonded insulation and transparent insulation, mean that, first, the atmosphere can’t get at the vulnerable copper surface and, second, that inspection of the surface for corrosion is trivial.

Some hams do understand the benefit of using insulated wire for an antenna. However, deterioration of the insulation under the depolymerizing effect of ultraviolet radiation and ozone reactions and the flexing implied by antenna service mean that water ingress and migration by capillary action are quite likely early on and, eventually, inevitable. In the Big City, a pH of 5.5 or less for rain water is not unusual and that will hasten matters.

Plastic can be prepared to resist ultraviolet attack but the insulation on common hardware store wire is not only not bonded in order to be strippable but it is not expected to be exposed to the elements. Water can enter through sunlight caused cracks and is free to migrate along the length of the antenna by capillary action, aided by the “working” of the antenna.

With magnet wire a glance at the antenna on a bright, sunny day is all that is required to ensure that both the insulation and the copper’s surface are in good condition. With the sun and the observer in just the right positions, a specular reflection can be obtained. If the antenna is a copper colour and gleaming, then there is no corrosion issue. A dull surface would indicate a deteriorating surface to the  insulation and greenish patches would show corrosion of the copper’s surface. To date, there has been no corrosion issue in the magnet wire used at this station. Essex is the manufacturer.

Wire, Close Up20150302/3. The old legs were taken down and new, longer legs installed, see below. This is some of the recovered wire. No cleaning has been done. There is no deterioration after six months’ service. Even Big City dirt doesn’t seem to be an issue.

The reader’s thoughts here might now stray to the realities faced by the users of antennas made of aluminum tubing. Aluminum is not a noble metal. It’s surface is rapidly corroded in a coastal climate let alone by rain water with a pH below 5.5. Aluminum oxide is a superb insulator and is widely used in that service so the least hint of corrosion on the surface of the tubing must raise consideration of I2R.

Readers considering using aluminum wire for their antenna because of its lightness and low price might care to consider the same reality.

A Later Refinement.

It had been clear from the beginning that the electrical length of the two legs was not exactly the same. The physical length is only part of the story. Important, too, is the proximity of objects and the height above electrical ground. In this case one leg is four stories above an asphalt paved parking lot that will have completely dry earth beneath it. The other goes down to three metres above a lawn and garden that will be wet earth. The last two or three metres run through tree branches. Under certain tunings there was a little r.f. detectable against ground in the shack and the logic­al reason for that would be that the two legs were not in reasonable balance.

20150302. The loading coil is gone. The original leg through the branches was extricated from the dead tree and taken down in the dawn hours yesterday. Advantage was taken of last year’s top growth of the healthy trees to place a new leg higher than the old leg. Length was 13 arm spans.

With dawn now advanced, a grumpy looking neighbour had come out to dump garbage and, as likely, to inspect at close range this eccentric espied from her apartment. In the dawn light, #26 wire and mono-filament fishing line would have been invisible; he was out attacking trees with a long pole and otherwise up to no good. A retreat down the lane was executed at once.

Please believe, dear readers, that it’s difficult for an unshaven man bearing a four metre pole topped with a coat hanger to adopt an air of insouciance!

Hanging the new leg for the parking lot run was abandoned for that morning.

In the first glimmerings of a spring dawn, the old leg over the parking lot was taken down this morning. The leg was replaced with another leg this one also 13 arm spans long. The replacement was a fait accompli before the appearance of early morning garbage dumpers.

Physical leg length will be a bit longer than a quarter wave at the cw end of the 80M band. Tuning is within the range of the Match Box. The antenna is flat on 80 cw and fone, 40, 30, 20, 17, 15 and 10.

So far there seems to be no r.f. at all around the shack. A few rain and wind storms will settle the catenary of each leg. Rising sap and summer foliage may make some changes, too. After that a little tuning of one or other leg may be in order.

2015030311:48 There’s sure nothing wrong with the new legs. By pure chance the rig landed up in the fone band on 40 metres. There was Roger, VK4YB calling CQ like a local. After juggling the adjustments here to set up on 40 metre fone, we had a long and very pleasant QSO. Mind you, it was a QSO from the ridiculous to the sublime. Roger has a fine set up in which he can resonate both his driven loop and its reflector. He’s a known good guy, too, since he uses open wire feed! All this with terrible conditions: at last look the “A” index stood at 28!

Tweaking the Old Antenna

Time will tell but so far this new antenna seems to be in perfect balance. This old section, below, that applied to the antenna in service up to the end of February, 2015, will be left in for the edification of those wishing to tune out a bit of imbalance.

The obvious way to handle an imbalance, of course, is with two men. One fellow tunes and the other fel­low prunes the overlong leg. Pruning and tuning here with only one man and four stories to go up and down was not practical. A further and just as important matter was attracting attention even in dawn hours. Remember that the overall design requirements include that of not drawing attention. The fewer people who notice this antenna the better. Unrigging and then rerigging one of the antenna legs over and over again would be the perfect way to get people to take an interest in an antenna installa­tion.

An investigation of the imbalance was launched [note, applies to the old antenna]. An ancient grid dipper given years ago by a fellow ham clearing his junk was revived and used to examine the electrical lengths of the antenna legs by coupling into the ladder line. There was a clear indication of resonance modes on each leg and they were not at the same frequency. It was diverting to discover that one could detect the dip of the two legs when connected to only one side of the feed line. Lots of energy was coupled across the open wire feeder even though it is very short.

Before the building was awake, correcting the issue was undertaken.

On Site Bench, 640, IMG_0001Field expedient bench.

Grid Dipper, 640Grid dipper dating back into the mists of time when Heathkit was still making Heathkits. It is model HD-1250. It had been assembled well. The joints were were hot and shiny. The old original that I knew had used a tube. The detritus on the housing is because the case in which the grid dipper had been stored had been lined with foam. Over the decades that the instrument had spent mouldering in there, the foam had dissolved into a black muck that had coated everything. The worst of the muck has been cleaned off. It remains to find a solvent that will dis­solve the residue but not dissolve the paint and plastic.

Tiny Loading Coil

To adjust the electrical length of an element two basic techniques can be followed. A series inductance will give the effect of lengthening an element and a series capacitor will give the effect of shortening an element. The technique selected for balancing the two legs of the antenna was to insert a loading coil into the electrically short leg. A series capacitor to “shorten” the long leg would have to be on a physical scale satisfactory for passing 100 watts of r.f. at substantial voltage or substantial current, depending on tun­ing since the element would be worked from 80 metres to 10 metres. That would have meant a large variable capacitor and a moisture proof weather housing. That would have been too obvious to an ob­server. A small inductor custom wound was much more discreet and it could be out in the weather if it were well covered in “coil dope”.

The legs were disconnected from the open wire feeder at the feed point. The “short” leg was then iden­tified with the grid dipper.

  Coil Test Set Up 02, 640, IMG_0003The loading coil at its fi­nal length.
(Seen here holding the turns in place during testing is NASA/TM -2002-210785 Manned Space Flight approved
and E.S.A. ECSS–Q–70–13, space product assurance conforming, Scotch tape…from WalMart.)

The coil form is an empty ball point pen cartridge that has a very thick wall. The winding seen here is the final length, 17 turns of #26 wire close wound. The coil had started out on the bench about twice that length and here has been pruned down to give a resonance the same as the other leg. It’s much easier to start out with a coil that’s too long and to prune than it is to start with a coil that’s too short and must have bits tacked on repeatedly and then wound onto the form while avoiding shorts between turns.

Prunings, 640, IMG_0008Coil prunings.

Coil Installed, 640, IMG_0002The coil installed.

Coil Detail

Once the number of turns had been determined, the coil form was cut to a suitable length. It was drilled and a proper winding was made. The coil on its form, seen here, has been sprayed with two coats of acrylic “coil dope”.

The mounting here has been sprayed, too, in hopes of preserving for a while the Starbuck’s stirring stick standoff in the West Coast rains. The author has been a customer of Starbuck’s for two decades and so was granted the stirring stick gratis. The world is much indebted to Mr. Howard Schultz and his company for that key contribution to a signal advance in the radio art!

Seat of the Pants

The reactance will change with frequency of course. This little tweak was all that was required for this particular antenna.

Readers with a formal background may be appalled at the rough and ready practice here. “About right” is good enough. Don’t burn up time with laboratory precision. That’s a misallocation of effort. In much of practical radio, what’s required is “ballpark” or, at most, “infield” precision and not “strike zone”, laboratory, precision.

Here there are steel vehicles parked or not parked in the lot beneath the antenna and in different patterns, there are dry or wet trees, there is changing foliage and sap content, rain saturated earth and dry earth, there is desiccated lawn or dewy lawn, at this building lawn left rank for months or newly mown, changing surface vegetation in the garden, wind rearranging the branches, wet or dry branches, the neighbour’s substantial aluminum clad r.v. beside the antenna or absent and catenary changing with wind and branch motion. Just recently [March, 2016] a length of chain link fence was installed beneath one leg and on and on. In moving from 80 metres to 10 metres each of those will have a more pronounced effect, too.  Remember the guiding principal of balancing all requirements. Effort is a resource: consider applying it where it matters and not where it doesn’t matter.

Flat Tuning

The station with that coil in place has been tuned up flat on 80, 40, 30, 20, 17, 15 and 10 metres. The tunings are all about as they were before that trimming for length. This time, though, there is no longer that occasional whiff of r.f. floating around the shack.

The antenna tuning is sharp, too, and that indicates that the “R” component of the impedance is small and that includes the “R” of the feed line. A broad tuning would indicate big copper losses. On 80, the antenna is short so the radiation resistance is low. That, in turn, means that a high current must be sustained in the antenna. If there were a substantial copper loss issue, tuning would be broader on 80 and, in fact, it is as sharp as on the higher bands.

You coaxial cable users stop off now and think about all that. If the combination of your antenna and feed system’s tuning is broad, why is it broad? Why isn’t the system sharply resonant? The assemblage is lossy, that’s the reason.

“Oh but I know it’s good because of a low voltage standing wave ratio.” Nope. That doesn’t count for two reasons. There’s power loss on the way to the antenna and the same dB power loss in the reflected energy on the way back down. The worse the coax, the better the reading. A hundred and more feet of coax mean a two hundred foot travel for the r.f. What’s seen in the station misleads the innocent.

The other reason has to do with r.f. on the outside of the coax. The least hint of r.f. on the outside of the coax renders the reading of the usual low rent reflected power instrument meaningless.

No Magic

No magic is asserted here. There is a surprise in that #26 wire works so well. After a lifetime of hearing “experts” insist that, at the very least, #14 wire is required and receiving the solemn assurance that stranded wire was mandatory in overcoming skin effect, it is genuinely amusing. How many of those “experts” had actually tested before giving down orthodoxy?  The sharp tuning and being heard consistently without difficulty on both cw and fone by other stations in these poor band conditions confirm that the antenna is radiating r.f. pretty well and is not simply an outdoor resistive load.

Don’t deny yourself an antenna because you can’t put up #14 stranded wire. This “cobweb” fine antenna works just…fine.

(Hey, by the way, on the general idea of amateurs exploring and innovating; Edwin Howard Armstrong, very much an engineer and a genuine expert; is widely quoted as saying that it was not what people didn’t know that mattered in the world, it was what they did know but which was wrong (it’s the latter “expert” in radio who creates annoyance here).

(That knowledge that was wrong seems to have been a pattern in radio technology’s early history. After Marconi’s innovative over the horizon transmissions violating theory, probably the best known and well documented case of an “expert” knowing better than a persistent innovator is that of Bell Labs and Carson. Carson of Bell Labs had declared early on that there was nothing to f.m. From fundamental principles, which he demonstrated in print, f.m., simply could not work. Carson was right but he was wrong: he was trying to stuff f.m. into a very narrow bandwidth (he must have been a telephone guy!) Armstrong explored f.m. anyway and we all know the outcome of his work.

(Armstrong had been a witness to the blooming of radio technology. He had been at the centre of developments. Armstrong stated publicly that radio technology had not been born in laboratories. He said that it had been “…the practical men…”, ham operators, who had innovated and pushed forward radio. Do you have an idea, ham operator? Give it a try.)

 

Approval from the Master

Tesla Looks Down 02, 640“Dobro. Looking good there, John.”

Gospodin Nicola Tesla gazes down from the wall upon the Johnson Viking Match Box and the interior run of 600 ohm feed marching across the room to the balcony door (#20 wire is used indoors where it cannot be seen from the ground).

The enormous ceramic stand-offs from a broadcast station are objets d’art, they lend a panache to the station. They are the gifts of Ed, VE7EF, a radio engineer of substantial experience. They had been harvested during his work. Unbidden he exhumed them from his junk box, cleaned them up and presented them. “A thing of beauty is a joy forever…”; ok, maybe one has to be a radio nerd to grasp the aesthetic! This is the ideal application for them: function and beauty! (Insulators of such magnificence are not required for the voltages encountered at 100 watts!)

Tesla is staring directly at the lad­der line. A slight smile has emerged onto his face so we may take it that he approves of the station’s new trim!

+++++

CW is A1

You hams will know too well that QSL cards, if they appear at all, take a long time to wander in so here are QSL cards from earlier #26 A.W.G. antennas off a balanced feed including one from a physician in Hiroshima:

Three QSL Cards for WordPressHiroshima QSL, erect, cropped

The Mighty KPH

See what the fellows are doing at what must be the best preserved shore station in the world, KPH, and the related KFS:  http://www.radiomarine.org/ . Yes, these fellows have the original frequencies still licensed and, yes, from time to time there are hams there who are holders of commercial tickets and the great transmitters, those that have been restored to date anyway, are put on the air on the original commercial frequencies. Similarly qualified hams operate the radio stations in museum ships and traffic is passed on the old KPH frequencies.

K6KPH is the ham station at KPH. One of the hams at the KPH ham station was worked on the 1941 R.A.F. short armed airborne key here with a glass arm from buck fever. Here’s the confirmation in the style of a KPH radiogram:

KPH QSL, Rotated

Bruce Chapman, W2ISJ, [below] had been one of the operators at KPH.

If you work K6KPH, change gears. One does not call up K6KPH using ham radio protocol but commercial protocol. Sharpen up your “Q” signals, too; you may be working a commercial operator. So far K6KPH has not instituted “the wheel” and traffic lists but…in the future who knows? Call using commercial protocol at 7050kc; yes, kilocycles ride the air yet at KPH. Call on a Saturday afternoon and see if you can get a KPH radiogram to adorn your shack.

Contacts

at 2014062407:28Z worked RI0F, Anuchina Island, and with no trouble. It was not a marginal contact, either; he had the call at once. He is still on there solid 45 minutes later later. That’s not across town, that’s 6,300km, 3,915 miles and working a portable, field, station. The station is a Russian dexpedition in the South Kurils, readers, worked on #26 magnet wire. It’s not exotic dx but it feels good on #26 magnet wire!

20150304 The QSL card for the RI0F expedition has arrived (click on for detail). It’s a beautifully composed and printed card:

RI0F, QSL Card, Front, 300 dpi, 1200, Horizontal

RI0F, QSL Card, Rear, 1200, Cropped, Rotated

Stamps, Rotated, Cropped

at 20140629 worked 50 Field Day stations “1E” on the battery bank before going off to bed. Their locations extended from Washington State to New Hampshire and from North Dakota to Florida. The points in between were well represented. Retries were not an issue. Grey line was not involved since bedtime was 04:00 Pacific Coast time. Whatever r.f. is going into copper loss there was no impairment detectable on this Field Day. Here is a selection: Newport, New Hampshire; Bridgeview, Illinois; Carson, California; White City, Saskatchewan; Hamburg, New York; Albuquerque, New Mexico; Topeka, Kansas; Huntsville, Alabama; Hales Corners, Wisconsin; Minot, North Dakota; Muskogee, Oklahoma; Melborne Beach, Florida; Kahului, Hawai’i.

K1RO Incoming QSL Card, 640

That is not a listing laboriously accumulated over weeks and in the peace and serenity of the wee hours of the morning or of stations worked only along the grey line but rather by being out there in the rough and tumble of Field Day and its QRM. Field Day on the cw bands is a roaring jungle; it’s with cw stations shoulder to shoulder competing for space and overlapping each other. A feeble signal would be lost.

at 20180624, Field Day

In between other doings over the weekend, 63 stations were worked in the 80, 40 and 20M c.w. bands. By recent standards, propagation was reasonable. The station started out as “1E BC”. At about the 39th hour, in the wee hours of the Sunday morning, the bank of aged batteries said:”enough!”. R.f. power out was reduced but chirping started again after another half hour. The battery bank was set for recharging and the operator toddled off to bed to do his own recharging. At seven the next morning, operation was resumed but now as “1D BC”.

KL and KH were worked. W6RO, the “Queen Mary” was worked. Carmel by the Sea was worked, that makes your day. As expected, there was a huge turnout in Silicon Valley including W6YX, the Stanford University club station. Stanford has a long, long connection to radio technology; read about the Poulsen arc. On the music side, Nashville and Escondido were worked.

All through this the fine old TS-930S delivered. She sliced away the tremendous contest QRM with her quadruple conversion receiver, 100kHz final i.f., very effective variable bandwidth tuning on c.w. and with the ultimate tool, the 250Hz c.w. filter that slices mighty fine.

Now on to the Canada Day Contest. Let’s hope for a good showing of Canadian stations this year. Canadian stations have been too few. We need a bit of luck with propagation, too.

Evanescent Fame

K8AQM ed; S.K.C.C. Newsletter, September, 2018; vol 11, no 3, p. 5. 

Ted has extensive coverage of the 2018 A.R.R.L. Field Day in that number.

at 20160307, Argentina, Chile, Columbia on Fone

Nearly everything on here has been about cw contacts. A huge fone contest was encountered on 40 metres last weekend. Fone stations were shoulder to shoulder; it was like the old days. Gasp, by band conditions suborned: your author had been seduced by the Dark Side, fone operation!

That led on to working, on fone, some of the non North American big gun dx stations on 40, 15 and 10. One was not a big gun at all. He was a 100W station in Argentina and he was worked without effort. The power here, of course, was 100 watts nominal produced by the good old TS-930S of VE3CTL.

You doubters of 0.40mm wire low to the ground down among apartment buildings, try these on for size: PJ2T, Curaçao; HK1NA, Columbia; JR2GRX, Japan; P40L, Aruba, worked on both 15m and 10m; LU5FF, Argentina, 100 watts; CE3CT, Chile; TI5M, Costa Rica. These were not only fone contacts using 100W, please note, but were made in the mad QRM pandemonium of a fone contest. Most of the competition would have had directional antennas and most would have been kilowatt stations. Little time was spent wading through that dense thicket of stations since contests hold little interest here. No time was wasted on a station, either; if three calls did not produce a contact, the v.f.o. was moved on up the band.

7QP Contest, 2017

The 7QP contest was pecked away at. The prospect of a contest draws c.w. operators out of the woodwork and onto the aether. Stations were shoulder to shoulder in the contest areas as they should be all the time across the c.w. bands. In spite of taking two breaks of three hours each for grocery shopping and coffee shopping and then dinner and a snooze, the fine old TS-930S with her wispy antenna came out 28th in her class of 78 stations. ( http://ws7n.net/7QP/new/Page.asp?Content=START&Page=2, “Non-7, Single-Op Low CW” ). That class includes California stations which state abuts four of the contest states.

Don’t suffer a dreary lecture on skin effect by trying to tell an “expert” that #26 wire works just fine…you know that it does.

at 20140713 a broadcast band filter has been added. (Old news but it may help somebody).

(The fine old TS-930S with her quadruple conversion is in no need of such a broadcast station filter. There is not the least hint of broadcast station induced noise.)

Filter for WordPress SchematicThere had been a rising suspicion that an intermittent rhythmic pulsing noise and regularly spaced patches of noise encountered when tuning along the 20 and 40 metre bands had had their origin in mixing going on in the receiver from broadcast station overloading. An antenna tuner is a preselector but maybe more broadcast band suppression were needed.

Yesterday cores were purchased and, last night, were wound and then the broadcast band high pass filter shown above was whipped up. The rig was taken apart last night and the filter was installed at once. The filter has done the job: both noises are gone. This beautifully simple circuit with it’s capacitors of common value is from the page of Joe Carr. It’s in his Technote #6. His little circuit receives one more hearty recommendation from this user.

at 20140725, the first station worked in paradise on the last antenna (16 June, Greenwich time). Byrce’s station is not a big gun. In our QSO (conversation by Morse telegraphy), he said that he was simply using 100 watts. From this magnet wire station, he reports 589 (that describes a strong, clear signal unimpaired by noise and perfectly readable). Our QSO was cut short by an “expert” who set up shop on our frequency. Bryce was so courteous as to send his card directly by mail, that’s why it’s here already.

KH6AT, incoming, 640

at 20140818, a QSL card in the classic pattern:K1RO Incoming QSL Card, 640K1RO Incoming QSL Card, Back“Your stealth antenna is working just fine.” Thank you, Mark Wilson, operating from Unity, New Hampshire.

KK6FUT, 640“Wow! Impressive that #26 wire is working so well…” Thank you, Ben Kuo.

At 20150115 an unbiased, exact, signal level evaluation. As a test, the reverse beacon network, was tasked with giving down an opinion of signal strength and coverage. The test consisted of sending “CQ CQ CQ DE VE7AOV VE7AOV VE7AOV” once and nothing more.

Reverse Beacon, 15, 150

This was simply a random test. The results shown are not the harvest of a “cherry picking” exercise. The test was run just that once and there are the results for all to see. The figures are uncoloured by a human interpretation. Can you understand now how the station worked so well on Field Day? This antenna functions as would any other antenna.

Worst case, the signal from this #26 wire antenna from all these North American stations is 10dB or better above the noise. A CW signal 10dB above the noise is armchair copy. It would be perfectly satisfactory even on fone.

At 20150101 Field Day and then Canada Day. The bands were poor. With the arrival of a TS-930S, the receiver situation improved beyond all expectation. The receiver in the rig overcomes the noise problem in this location. With it’s quadruple conversion and with the 250Hz filter switched in, c.w. becomes a delight. Only half of field day was worked. Canada Day was worked intermittently. We need more c.w. operators on Canada Day. Without the contribution of U.S. stations, for which many thanks, it would have been a sparse day. Very feeble signals were received and their stations worked. The provinces to and including Québec and, heureusement, une station de radio française. That’s the first European station on this set up. France on 0.40mm wire.

CW Contest 20170219. Local noise seemed to be down a bit so dabbled in the A.R.R.L. DX contest now and then to harvest what are, here, interesting calls. Worked CE3AA, Chile; ZM1A, New Zealand; HP3SS, Panama; VP5K, Turks & Caicos Islands; FY5KE, French Guiana; and a few routine stations on 40, 20 and 15. No exotic DX, others are welcome to the “enjoyment” of pile ups. The station encountered that had the coolest “facilities”? Now that would have to be KL4SD; have a look on qsl.com. Enforced operating breaks at that station in mid February would be…brief!

“That’s the best QSL Skinny Dick’s has received. Loved the wire. All the best, Traci KL7TH” Thanks, Traci.

“…the wire.”? You see, reader, if you work VE7AOV and you receive a QSL for the contact, you are entitled to a specimen of the wire, affixed right to the QSL; the thin, thin wire from which you heard the signal all the way from Vancouver!

Bastille Day Eve, TX5EG, Ahe Atoll!

The sole, lonely little signal late in the evening of the 13th, West Coast time, plaintively calling on 40M was a chap out in the middle of the Pacific. That would have been the eve of Bastille Day in French Polynesia. The signal was minute here, a whisper, creeping up out of the noise and ebbing away again.

How can the entire 40M c.w. band be empty but for one peeping little signal from Paradise? That’s radio, folks.

That was the only station on the band so the rig was left on the frequency all set up with the 250Hz filter in and set for working split (the TS-930S has a second v.f.o.) in hopes of catching what is, for here, satisfactory DX. As the minutes went along, there was no real improvement in the signal so, finally, on one of the slightly better waverings, a quick, single “VE7AOV” was sent. BANG! Didier had the call instantly and responded. Ho! Some guys fish for trout with Dynamite and some of us use light tackle. The light tackle here captured the TX5EG dexpedition. Fellow apartment dwellers, you, too, can do this.

There’s more of interest. Didier says on the site, above, that they had lost an amplifier. That being the case, the station worked might have been simply a 100W station. If the fellows were operating without an amplifier on 40 at the time, then that makes working TX5EG 10dB, Watts, more delicious.

Ahe Atoll is part of the Îles du Roi Georges.

In hopes of receiving a paper QSL; a card, s.a.e. and a letter, in school room French, have gone off to Didier.

It happened!

 



So…

Readers, please refrain from dismissing a #26 wire antenna from first principles as set out for you by an “expert” who is merely pronouncing truths ex cathedra.

It is a fundamental element of the real ham radio operator’s make up to challenge orthodoxy. We hams have been doing that from the beginning of radio. In fact, in early days, it was exactly how the technology of radio communication was advanced.

In the use of #26 wire (it must be magnet wire with its bonded insulation) and in other matters, use your own brains.

The idea works well. A wisp of an antenna less than half a millimetre in diameter doesn’t bother others. It works electronically, you have seen that for yourself, above. It does not keep falling down, either.

Get back onto the bands, you apartment dwellers!



Two Treasured Items

Some of us think that it’s on cw (Morse code communication) that one meets the most interesting people. Anybody can yap into a microphone and, too often it seems, that’s just what is going on. Immediately below is the text of a card from radio station W2ISJ. This gentleman had the most beautiful fist. It was like listening to a machine; the characters just flowed into the brain. (Hand sent Morse is as distinctive as cursive hand writing. It ranges in quality from chicken scratches that are a constant labour to figure out to characters as easy to read as a printed page. Bruce’s cw was of the latter quality.)

For the uninitiated, the text below says that he was a radio operator at the world girdling shore stations in their days of greatness. Ships’ radio operators all over the world worked men like Bruce Chapman sending and receiving messages. The special delight here is not just working a prince of the profession but a fellow demonstrating that the moment a blind man sits down at a key he is on an equal footing with everyone else. Bruce was at the absolute acme of his profession. No weak sisters would be tolerated at stations like KPH, WCC or WPA and Bruce did that for 35 years.

W2ISJ, Censored

This gentleman, Albert Montague, “Monte”, said in our QSO (conversation using Morse code) that he was a survivor of the Pearl Harbour attack and he that had served in submarines in the second war. He was worked on the latest of the antennas; he was kind enough to mail his card directly so it has arrived already. The first logo on his card, difficult to see here, is that of the “U.S. Submarine Veterans of World War II”. The centre logo on his card is that of the “Pearl Harbour Survivors’ Association”. (Click on the card for an enlarged image. “Drag” the image as required to see the logos.)

AB7WS, Pearl Survivor

Now where else can we chat with such interesting and worthy fellows? Get onto cw, you fone operators. There’s lots of room for you, the cw bands these days are almost vacant. Your author is no good at all on cw but he sure enjoys it: “If it were easy, it wouldn’t be fun.” Meet guys like Bruce and Monte; pound the brass.

Now This, This is Radio

DX hounds…how many of you can claim to have worked that obscure, that exotic dot out in the Pacific Ocean, Mayne Island? Well look at this. Here’s a QSL card from Canadian 7SL on Mayne Island. Things don’t move as fast there as they do elsewhere; QSL cards haven’t changed since the ‘twenties:

Here is the equipment that was used in the contact documented in the QSL card above from Radio 7SL. It’s actually advanced since it is using crystal control; if not QSL cards at least technology is marching forward out there on far distant Mayne Island! A 6AG7 (a bit modern) is controlled by the crystal that you can see there and that stage drives a mighty 6V6 to give a full five Watts out even up on 21,000Kc. When this contact was made, the crystal was not in use. Heathkit’s v.f.o., the VF-1, much advertised in the QST of the mid ‘fifties, was in use injecting a signal into the crystal socket. Now the signal might not have agreed with the “…shall exhibit the stability characteristic of crystal control…” as we have all read somewhere! It was a delightful signal, an echo from the post WWII era. It would have brought a grin to the face of even the most dyspeptic Radio Inspector.

Look at this superb execution. Radio can be art. Here is art. They don’t make’em like this any more. In fact, they didn’t make’em of this quality even in the ‘twenties (this actual circuit is a post war revival. It’s a minimum transmitter using two 6V6 tubes to get guys back onto the air after the war). Such equipment was more usually a rat’s nest of wires tacked down onto a plank and, at the very least, had a separate chassis for the power supply.

What shall we expect next year, Steve, tuned grid/tuned plate with fine tuning by hand capacitance?

Be certain to go to Steve’s blog.  There are radio riches to be indulged in there from long, long wave all the way to light wave. Steve is a man of parts. By moving through Steve’s material, you will learn more about the “Longfeller” transmitter shown above. To start off reading about ‘twenties construction more generally, click on this link.

N2DS, High “Q”

Now you more sophisticated readers will know all about the importance of achieving high “Q” in resonant circuits. Don’t be too sure that you know the last word on that subject.

Above, you read about fishing with light tackle. There’s a whole community in radio fishing with even lighter tackle.

A recent acquaintance worked this station on 20M from an adjoining neighbourhood; there were no other signals on 20M. After that heavyweight DX, we decided to meet in a coffee shop. This fellow related his earlier experience with crystal sets. He had been experimenting. He had achieved a success that was astonishing. He was able to receive local broadcasting stations without hearing three of them crowding into his little receiver all at the same time.

Those of us who messed around with crystal sets as children in the ‘fifties, using the bedstead as an antenna and so on, took it for granted that we would have to endure heavy QRM. It turns out that the fellows who pursue this branch of radio have an understanding of high “Q” that has eluded us mere plodders. He gave a reference to the website of N2DS. The way these fellows achieve such astonishing selectivity in the stupendous µV/M levels commercial broadcasting stations saturate the Big City in is with spectacular “Q”. Every design detail matters in achieving that “Q”.

These guys understand radio.

N2DS, Dave Schmarder, has a great page up. Have a look at his designs and read about not only his and others’ successes with broadcast receiving but with short wave, too. Go here. (Linked by Dave’s kind permission).

There’s a new world out there to discover in sophisticated design in the most humble of receivers, the crystal set.


Here’s a recent email exchange, readers. The email that sparked the exchange is at the bottom:
From: “KB4QQJ@aol.com [skcc]” <skcc@yahoogroups.com>
To: skcc@yahoogroups.com
Sent: Tuesday, December 8, 2015 4:01 PM
Subject: Re: [skcc] EndFedz (Joe WB9SBD) and John VE7AOV

Joe,
John VE7AOV has shown some real knowledge and near bout nailed it!! Well said and well spoken John.

I can assure you Joe, loss is something “all” antenna systems have. It’s only stupid if you don’t know how to correct it.  I can also assure you there are no resistors in the matching transformer of the QUAD or the 10/20/40 multiband antenna by LnR Precision. There is no mystery here. It is a step up transformer with compensation across the  input. Simple dimple and danged efficient.

Most EFHW designs place a capacitor on the antenna side of the matching transformer,  then it’s tuned to resonate at one frequency. The EF-10/20/40 has no resonant tank circuit on the antenna side. We use a 150 pF capacitor across the coaxial 50 ohm side. Old school stuff from a very knowledgeable designer.

If you are really interested in learning the magic of the antennas, by all means contact me off list. I love those types of discussions. If you want to see what other knowledgeable folks have done to “unwrap” our antennas it can easily be found on the web. This is one of my favorites:

http://www.hamradio.me/antennas/lnr-precision-ef-102040mkii-examination.html
He does a great job of demystifying the antenna.

But make no mistake, the losses are very low and much more acceptable than a multiband current fed dipole using a single coax feed and a tuner.

73 for now,
Randy_KB4QQJ
LnR Precision Inc.

PS: Just for the record our web site doesn’t say: Pwer Handling: 200W SSB/ CW 50W A.Mo”

  It states:
“Power Handling: 200W SSB/CW 50W A.M.”
+++++
This is the exchange of correspondence to which KB4QQJ is referring, above:

—In skcc@yahoogroups.com, <if455kc@yahoo.com> wrote :

“…and the only reason it has a limit is because of the losses in the box generate heat and any higher than 200 watts and it cant [sic] dissipate the heat fast enough without having damage.”


Just a moment, chaps.


It is quite so that an important element in the “magic” proprietary antennas we have seen over the years has been a resistor to make them broad. That resistor, of course, dissipates some of the transmitter’s output and so heats up the “box”. It decreases the level of outgoing signal. (A minor consideration, often neglected, is that a broadening resistor has exactly the same attenuating effect on signals coming into the receiver.)


Those antennas have generally been current fed antennas of one flavor or another.


Please consider what the manufacturer has made here, everybody. This antenna is not a current fed antenna. What we read is to the effect that it is a voltage fed antenna. That’s pretty clear from the documentation. The “box” is at one end of the radiator. We can see that for ourselves.


There is nothing new in the idea of a voltage fed antenna and there is nothing wrong with the idea. Where there is an issue is voltage. Do a little arithmetic based on a feed point impedance of, say, 3,000 ohms and you see at once that voltage is an issue. At 50 ohms or so that feed point voltage is low at ham radio wattages so users of current fed antennas are not accustomed to thinking about feed point voltage.


It is a delight to see that the designer asserts that a v.s.w.r. of 1.6:1 is acceptable. He knows his stuff. With that detail in his documentation we can have some assurance that he has not included a resistor. He is a brave man to have made that assertion in his documentation in the face of the former c.b. crowd’s intransigence over the necessity of flat line!


The designer of this antenna may very well have based his wattage specification on voltage considerations. As suggested in the recent post, there is going to be a transformer for transforming the low impedance of coaxial cable to the very high impedance of the end of the antenna and for isolating the coaxial braid, too.


We might reasonably suppose that the power limitation has not to do with I^2 R losses but has to do with the very high voltages implied by feeding a very high impedance.


John
at radio station VE7AOV
(I have no knowledge of or relationship to the manufacturer.)

This is the posting that had prompted the response above:

 


From: “Joe nss@mwt.net [skcc]” <skcc@yahoogroups.com>
To: skcc@yahoogroups.com
Sent: Tuesday, December 8, 2015 6:52 AM
Subject: Re: [skcc] New Radio (Joe WB9SBD) [1 Attachment]

 

And I did not say just 50 watts I copied directly from their page below it clearly says 200 watts. SSB/CW
And the box I would be pretty willing to wager if you open it up there is a small toroid or a resistor or BOTH in there, and thats where the losses are. The limit of power is because of whatever is in that box. and the only reason it has a limit is because of the losses in the box generate heat and any higher than 200 watts and it cant dissipate the heat fast enough without having damage.

Basic antenna 101

Joe WB9SBD

 

 


© MMXVIII copyright Nightingale


 

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Orientation and the Basic Units

Intuitive Electronics and Other Stuff

“I have no satisfaction in formulae…” -Kelvin.

“I rely on intuition a great deal.” -Hawking.

Some people become all excited about the complexity of electronics. That’s especially so for radio electronics. A befogging factor Authoris mathematics. These days, unfortunately, that fogging extends even to simple arithmetic. So, how about electronics without either? That’s what we will do here. Here we will have a pleasant wander around electronics and touch on other matters and end up in radio’s electronics but without math. and without even arithmetic.

No formulae. No formulas. Nope, not a single one. Guaranteed.

Come for a stroll.

(Listen carefully. Do you hear that seismic rumble making the blogosphere quiver? It’s all the engineers out there having a belly laugh at that and saying: “No math? What a maroon!” It can be done readers; just follow along and you will come to understand radio technology in a way few others do: you will understand it intuitively.

(Mathematics is important in science and engineering. Nobody doubts it. It is the exact language required to express physical realities. Oh, but are you a scientist or an engineer? Are you in need of exact descriptions of what goes on in a circuit? No? Ok then, let’s go.)

Even Lord Kelvin, a full professor at the ripe old age of 22, wanted a feel for what was going on. When it came to concrete reality, a formula was not good enough for him.

Listen to Lord Kelvin on the subject:

“I have no satisfaction in formulae unless I feel their arithmetical magnitude – at all events when formulae are intended for definite dynamical or physical problems.”

– The Baltimore Lectures of 1904, P76.

How about Hawking, no math. lightweight he:

“I rely on intuition a great deal.”

– broadcast, Desert Island Discs, 1992.

 

The electronics and some other stuff about radio is what we will get into eventually but right now we will do some ordinary electronics so that the radio stuff and other electronics makes intuitive sense later. It’s also interesting stuff by itself. It will, er, illuminate everyday life.

Lies.

The first thing to tell readers of these items is that what you will read about electronics here and elsewhere, too, is lies. Yes, lies. What is to follow in the explanations is all “lies”.

Sadly, the vast majority of practitioners of electronics themselves actually think that their every day view of the subject is reality. It ain’t.

Ask a low grade academic or an engineer about electric and magnetic fields. He will put a sombre expression onto his face, wave his arms and talk about electron motion, force lines, near field, far field and orthogonal lines of force. The truth, reader, is that there is no such thing out there. Not any of it. His explanation is b.s.

There is something. Oh, yes, there is something. It is not the sweet suite of concepts that that speaker has in his head. What that fellow has in his head are the “tools” mentioned above. A Gell-Mann or a Feynman would have given you a better answer and both still will if you trouble to read their stuff though even such as they didn’t really understand. It’s beginning to look as if nobody really understands the fundamentals.

Yet.

There’s sure no sense in us ordinary mortals poking around in a physical reality that the great minds of our time have been tinkering with for nigh ten decades and still can’t grasp.

What really goes on in electronics, you see, takes place at the quantum level. That fact has to be dealt with because, with more reading, you will bump your nose up against quantum weirdness.

Quantum physics is so weird that it is beyond weird. The electrons we in electronics so cherish are particles, they have mass (they weigh something), but they can be demonstrated to be waves. What? How can a wave weigh something? Yes, the “handles” that we have from our everyday world don’t allow us to understand. An electron is what it is and a photon is what it is and the totality of either of them has not yet been comprehended.

Quantum physics is right, universally right and Newton’s world is “wrong” and universally “wrong”. It’s only down at the fine grain that the difference matters. For us common mortals, the quantum world is of no help whatsoever in understanding “our” world of every day experience. We don’t need quantum physics to understand that water runs down hill. Newton’s view will do us fine.

So, what you will be reading here is going to be a body of “lies”. That’s where the lies come in. The lies are ok, though and there are two reasons why. The first reason is that they are all agreed upon. They are a universal language. They are rather like Lt. Bonaparte’s “set of lies agreed upon.” We need some consistent framework to operate within.

To understand the second reason, consider ye the plumber. To do his job in his world, he needs tools. He needs a Stillson wrench, a propane torch, solder, flux, a hack saw, glue and so on. He does not need a degree in metallurgy to solder a copper pipe fitting. He does not need to grind through five years of organic chemistry in order to glue his plastic pipes together. Capiche?

More. You change the wheel on your car after the merest brush with the sophisticated metallurgy of today’s fasteners and the forging, tempering and maybe even the case hardening and plating of your wheel wrench. You know the lug screws are not mild steel and you know that the wheel wrench won’t snap in your hand when you heave on it. It’s enough to know those facts.

We already make use of “lies” about our physical world every day. Don’t be alarmed. We need comprehensible tools and that’s what will be provided here. For a hundred years we have understood that Newton’s framework doesn’t work in every case. When you leave the freeway and drive off onto the curving exit road you feel a thrust to the outside. You think “centrifugal force” and “centripetal force” and not encountering “space time”! Mr. Newton’s explanation works just fine for us. The world actually doesn’t work that way but Newton is good enough for us. That’s the principle followed in these pages.

Enough.

An engineer experienced out in the world understands that a design is correct when it is good enough and no better. Our little wander through electronics will be good enough for us and no better. Making it “better” will get everybody befogged and snarled up. It will not be “better” because making it “better” will instantly exclude the innumerate. The innumerate will not be excluded here.

Now let’s dabble.

Electric Current

Electrical current is electrical current. Moving electrons are not like the flow of water. Analogies are dangerous because people like to extend them far beyond what was intended. So, if somebody has tried to tell you at some time that the flow of electricity is like the flow of water, please forget that right now or we will end up in, er, deep water.

When electricity moves around, it drags “baggage” with it. In fact, it is by its baggage that we know it. It has an electric field around it. It also has a magnetic field around it. For those of us in radio, implications of those facts bring great delight. When an electric charge changes velocity, it radiates energy. That radiation is a wave or a photon, as you like. To some of us that latter fact brought us a living. (Remember, please, “fields” are “tools” used by us to make sense of the world. They are our “wrenches” and our “hack saws” but they don’t really exist in the way the feeble intellects that run in our meatware imagine.)

When electric current “flows”, it really doesn’t flow. That’s a bit of a bad term but we are stuck with it. Really electrical current doesn’t flow, it oozes! Electrical energy is moved by one electron shoving the next electron. What electron flow lacks in speed it makes up for in volume of electrons. A few electrons moving fast is not what to think about. Instead, the reality is a truly astronomical number of electrons creeping along a wire. Creeping is what to think about, not rushing. Think “energy”. It’s the energy that each electron passes on to its neighbour next down the line that is how electrical power is moved. The fast moving energy is in the ”shove” not in the travel of the shoved electron. Electrons do not rush about in wires at near the speed of light but they do pass on energy at relativistic velocities.

In this area of electrical current and magnetic fields we owe a lot to fellows named Ampère and, a bit earlier, Ørsted. Ampère, by the way, had a tough life. He was not an academic but he was no dummy. In this amble through electronics, we will meet others of that mould. Do read about Ampère at some time, there will be lots of material out on the web. Among other things, you will learn about that great innovation in efficiency, the mobile Guillotine!

With no instruments that we would insist on today and without even a decent source of electrical current, these fellows worked out the basic idea of the fields around wires carrying electrical current. We still use these guys’ ideas.

What Ampère, Ørsted and others realized was that electrical current had a magnetic property associated with it. Electrical current flow produced the same thing that a magnet had around it. Ampère, particularly, worked out, without “proper” instruments, how the magnetism’s strength decreased with distance from the electrical current. He also realized that it came in two flavours, depending on the direction of the current flow. The field in each case was the same…only different.

We make sure Ampère is not forgotten by calling a unit of electrical current flow the Ampère. You will hear that unit and read about that unit casually as the amp. Properly, one should only use the official abbreviation “A”. There’s nothing official about this blog so Ampère or amp will do us just fine.

To give you an idea of how much current an Ampère is, a toaster or an electric kettle might take 10 Ampères to make it work. A 100W light bulb would take about one Ampère to make it work. An ordinary household circuit breaker will open at 15 Ampères. Each of the headlights of your car will draw about five Ampères but at a tenth of the voltage of household circuits. We will get onto the implications of voltage very soon.

Back to the magnetic field around current flow…

But, but, but to get a magnetic field from electrical current flow you have to have a coil of wire, don’t you? Nope. The advantage to a coil of wire (a solenoid) is that the individual fields around each of the wires in the coil are added together. Just one straight length of wire has a field around it, too.

You can demonstrate that for yourself if you have access to a d.c. welder out in the garage. Lay out the cables between welder and stinger so that they are hanging freely in the air and very close beside each other but not touching. Watch what happens when the arc is struck. The wires twitch and swing apart a little. If there’s lots of cable, contrive two such runs. This time have the hanging runs nearly against each other and with current flowing in the same direction. When the welder strikes his arc, the cables will twitch together a little. No coil but even so there’s a magnetic field present.

We arrive at an interesting detail here, by the way. That detail is the Ampère-turn. The amount of magnetic field that a wire has around it depends on how much current is flowing in that wire. If there is twice the current then there is twice the magnetic field. Duh.

One mouse can’t pull the Flying Scotsman to Edinburgh but a million of them can.

Hmmm. But if there were the same current and twice as many turns in the coil, then what? Same thing: twice the field. Ah! We have arrived at the Ampère-turn. Ten Ampères flowing through a hundred turns of wire will produce the same field as twenty Ampères flowing through fifty turns of wire. It’s the truth.

Yes, and five Ampères flowing through two hundred turns of wire will produce that same field.

Twice as much is twice as much. Is that complicated?

You can have fun with this if you like. Ordinary nails are made of pretty poor steel. They make a good core for a solenoid. A core inside a solenoid provides an easy path for the magnetic lines of force (lies, remember) created by the solenoid. Air is inhospitable to lines of force. “Soft iron”, in contrast, lets them flow really well. So a “core” is used inside a solenoid (a coil of wire) that’s intended to make a magnetic field in order to get a good flow of magnetic force lines. The idea of a core within a solenoid is even used in radio circuits and we will get onto that sort of thing shortly.

A simple d.c. power supply like a d.c. wall wart connected, briefly, that’s briefly, across about a hundred turns of small insulated wire wound around a nail will make a magnet out of the nail during the moment that the current is connected. Two hundred turns is…twice as good. Left connected, the wall wart will smoke. “Briefly” does mean briefly. We say, in electronics: “Smoke is put into electronic equipment at the factory. Once it has been let out of it again, the equipment won’t work any more.”

You may notice, by the way, that the nail is still a tiny bit of a magnet even after the pulse of test current is removed; tiny metallic particles will be found sticking to it. We will bump into that effect later. It’s the reason that tape recorders worked.

Electromotive Force

Electric current doesn’t flow unless it is forced to do that. It has to be pushed around a circuit. You have to push it otherwise it just sits around doing nothing. If it doesn’t move, you don’t even know it’s there. We only know a current is present because of the baggage that it carries with it and we only see that if the current is in motion.

The push applied is electromotive force. That’s probably the last time you will see that term in these items. It’s mentioned because you will come across the expression “e.m.f.” or even “emf” in other reading and so that term mustn’t be a mystery to you. Now you know what that is…you can forget about it! From now on we will just say “voltage” because that’s what you will generally encounter in other reading. It’s not a correct term because “volt” is the unit of force, its not the force itself. We don’t say, for instance, “miles-per-hourage”. We say speed or velocity. In electronics, though, we are bad and say “voltage”. We are just as bad about current so be prepared to hear “amperage”. (Worse still is “ampacity”; it’s electricians who are guilty of kicking that one around!)

So no current gets going without something to kick it along and that something we call, incorrectly, voltage. (Volta, by the way, was the fellow who came up with the first really good battery. It consisted of a number of cells connected in series (literally stacked on top of one another like hamburger buns and meat patties). At the time and in 19th century material generally you will find it called the “Voltaic pile”. (Those readers who have had a brush with French will recognize “pile” at once.)

Before the voltaic pile, most laboratory work on electricity was done using what we would call today static generators. The voltaic pile permitted work on current electricity: “electronics” gained wheels.

Now an idea is glimmering in your head. Remember the ampere turns business: double the ampere turns gave twice the magnetic field. Would it be true to expect that double the voltage would give double the current? Yup. That’s just how it works.

With that revelation we can stop off and consider the energy in a circuit. The amount of current flow represents energy. Of course the amount of “push” in a circuit is also an expression of energy. We have seen that if twice the current is flowing then there is twice the energy in a circuit. Exactly the same thing can be said about voltage. If twice the kick is being given to the electrons to shove them into creeping along then that means twice the energy is present in the circuit.

Those two ideas can be connected, by the way. Now think about this. Think. In order to get twice the current flowing you are going to have to push the electrons twice as hard. Hmm. Twice a twice. Twice a twice is four times. All in all then, if the current is doubled and the voltage is doubled, then four times the energy is present in the circuit. Not complicated is it?

The energy in the circuit is measured in Watts. (Watt did a lot of thinking about the work output of machines. He realized how wasteful of energy were the steam machines of his day and he fixed that. That’s why we owe him the honour of calling the watt the watt. He didn’t have a degree but he was no dummy. We will meet others of that ilk in this wander through electronics. Watt’s technology was condensing low pressure steam and atmospheric pressure (“vacuum”) in those early days but work is work whether done by a Watt steam vacuum engine or by electric motors turning shafts.)

Working Units

Back in the 1880’s the working units of current, voltage and power were settled on. Their relationship was made, arbitrarily, to fit together. It was a sensible arrangement. The fundamental “tools” of electronics were made to an interlocking standard like screw drivers and screw heads and wrenches and bolt heads. One ampère pushed along by one volt in a circuit expresses the power of one watt. Two ampères pushed by one volt have a power of two watts. Two amperes pushed by two volts have four watts and so on.

Now ask yourself: is electronics complicated? We are going to proceed like this all the way through radio circuits.

We mentioned, above, a 100 Watt light bulb. We have reached a plateau now since we have the three tools of amps, volts and watts. Now we are at this august height, we can play with that 100 watt figure. If we have one ampere flowing, then to get the 100 watts coming out of that light bulb, there has to be 100 volts of push on the current. It ain’t complicated.

It is just as true to say that if we have 100 amperes flowing then there has to be one volt of push.

We could play with this relationship some more. If we cut the current in half to 50 amperes, then to get the 100 watts, we would have to double the voltage. 50 amperes at two volts is 100 watts. It’s true. If we went on with this and cut the current by a factor of ten we would have to jack up the voltage by a factor of ten so that we can still arrive at the 100 watts.

An ordinary household circuit in North America has in the vicinity of 100 volts “push” in it so a 100 watt light bulb takes about one ampere of current.

Resistance

Remember that to get anything happening, we had to have a voltage to push along the electrical current. Without push, nothing happened. Ah. So there is a reason that current won’t move. That reason is the last of the fundamental elements we need in getting going in electronics. This resistance to the flow, er, creep of electrons is called…”resistance”. It’s a technical term not so difficult to remember, yes?

Remember just above where we played around with the new tools we had? Like the other “screw drivers” or “wrenches” of amps, volts and watts; the working unit of resistance was fabricated so that it would fit in with the other tools.

Now we can really play with the units. We’ve got them all now.

We started off with a 100 watt light bulb, remember? To get the 100 watts we pushed one ampere through the bulb and used 100 volts of push to do that. So, ah, if we had to jack up the voltage to 100 to move so little current as one amp through the bulb, then how much obstruction, “resistance”, were we pushing the current through? Would you believe 100 ohms? The ohm is the unit of resistance (as you might have guessed!)

Let’s play with our old original example. If we now go to two volts from the one volt that we had, we will push twice as hard. Pushing twice as hard means twice as much current will flow. Twice as much voltage and twice as much current at the same time is a “twice twice”. Twice twice is four times so now we have four times the wattage.

Ah, but lets now play with resistance since we have just picked up that little detail of resistance in a circuit. Let’s use that same example, that is to say two volts of push but this time we will put in two ohms of resistance instead of the one ohm we started with for that two volts to push against. How much current will two volts push through two ohms of resistance? It’s only going to be able to push one amp through that two ohms. Ok, what sort of power will that turn out to be? Two volts of push but only one amp now. Let’s find out who sees how many watts that is? (You don’t need a formula for that; come on now!)

Look how the units fit together. One volt will push one amp through one ohm. In doing that, one watt of energy is being used. Now, please, is electronics complicated? Look at that. Is it complicated? Who out there needs a formula to understand that?

Does “Ohm’s Law” sound daunting? Well, you already know it and didn’t know it. One volt pushes one amp through one ohm. That’s Ohm’s Law. Dazzle the fellows in the coffee room by tossing around your knowledge of Ohm’s Law. “Hmmm. This toaster says ’10A’ on the label. So it draws 10 amps at 100volts. It’s resistance must be 10 ohms.”

You can conjure current from wattage, too. “The toaster. Oh, yes. It says here on the label ‘1,000 watts’. At the 100 volts or so we have in the wall and with it’s 10 ohm resistance, that means that it will draw around 10 amps.”

The basic units fit together very tidily.

Enough for this first day.