Prepping: Project Big Ears Part-2

For this to make a lot of sense, you will want to revisit the original September 30, 2018 article Project Big Ears here.

The goal of the project, to refresh, is to build a high-performance Beverage Antenna using commonly available parts.  That first article was mostly the theory of what the project was about.  Today, we’re going to do a walk-through of the project up and operating.

First, though, some perspective:  See the 295-foot long high performance receiving antenna?

Thanks to “visual clutter” this kind of antenna pretty much “disappears” in a camo visual field.  Which is fine.

Let’s begin at one of the radios.  Remember, if you’re going to use this kind of antenna, a special receive-only-antenna facility must be included in the radio set-up.  This is because this kind of Beverage Antenna is crappy when it comes to transmitting.  The “law of reciprocity” isn’t perfect!  Useful?  Sure.  Perfect?  Hell no.

At the radio there is an antenna switch with two coax runs in from the matching network on the station-end of the array.

The antenna 2 position will eventually have a shorting plug for high lightning conditions, but for now it doesn’t matter.  I’ll explain why in a moment.  The single coax run (bottom of picture) goes to the radio.  To the left, the main receive lobe is to the south/southwest while to the right it’s off to the north/northeast.

If we follow the two coax runs through the wall and outside to the canopy built last year over the guest room/gym door, you find this:

If you squint, you can see the matching network – made by K1FD – safely ensconced under a sheet of thin plexiglass.  The idea was that  smashed the ground rod in almost 8-feet, and then put a big gob of “5-minute Epoxy” on an additional ground clamp and so mounted a nice weather roof.

Up the post from there is a simple knife switch.  This is pretty slick because it has a reasonable insulation leakage path AND because when it’s left in the OPEN position, there is no way for lightning to come into the radio room (via this route, lol).

The center of the knife switch goes to the radio-side matching network.  The leads going up head to the first wire run (S/SE-N/NE) and the lower will be for the W/NW-E/SE wire which is a sunny-day project.

The wire goes up the post where it is secure with 5: Electric Fence standoffs…

Notice how it rains when I go picture-taking:?

OK, from here, the antennas cross the yard to the first tree where one antenna heads generally south, the other will be heading west….

While my buddy the Major was up in the tractor bucket slamming the insulators in, he also gave the finished standoffs a quick spray of camo paint to help the antenna disappear.

So it wends and winds 295 feet along until it comes to the distant end:

At this end, you can see the rain cover more clearly.  I got “projectitis” and I will have to go back and finish slamming this ground rod in.  But not in  a big hurry for that.  About 10-minutes worth of project that will double as exercise with a sledge.

The real “invention” to come out of this is my “ladder line holding end tensioner” that looks like this when installed:

Working with “ladder line” or “twin lead” (I was using part of a 500-foot roll of old ChannelMaster wire I’d picked up on eBay for a song) the key thing to remember is sharp bends are bad for radio leads.

Here’s a sketch of the solution:

I’m not very good at “technical drawing” (it’s much neater in my ‘mind’s eye’ – honestly!)  but this is one of the reasons ham radio is so much fun.  Very much like flying.

That is, in flying you get a lot of everything:  Gas  engines, mechanical systems, airfoils, flight dynamics, radios, navigation, government rules and procedures, and did I mention weather, night ops and so forth?

Well, the same “buzz” from the use of all skills comes with ham radio, too.  You get construction, theory or electronics, a lot of antenna skills for all conditions, operating skills, bragging rights and all the rest.  Soldering, test equipment, Morse code if desired and so forth.  And who doesn’t envy a 60-tower?

Very much in the finest tradition of the Home Handy-Bastards Club (HHBC) because we know we are prepped because not only do we have all the tools and the brain power, but we also have projects galore that give evidence to how smart, capable, and wiser than the “other monkeys” is we.

Yeah, Yeah…How’zit Work?


On a full-sized Off-Center-Fed Dipole (60-feet up, 45 feet on one side and 90 feet on the other) I can hear (on the AM radio dial) about eight radio stations that are “listenable.”

With the Beverage on line? 47-stations!  OK, probably more, but I didn’t have all day to count.  But almost something to hear every 10 KHz which at mid-day and that is flat AMAZING.

On the ham bands?  Well, it’s not too much better than the OCFD antenna at times.  But, remember the Beverage is a wave antenna.  Where it shines is far-off stations – day or night.  Low incoming angles – so DX (distant) stations.

I used it on the 20-meter ham band and was shocked to learn that it could sometimes out-hear the AS-4WB tribander up at 65-feet.  Yee gads.

At night on SSB, I can measure *(depending on frequency)_ about 15-18 db of null, depending on whether a station is generally north or south of us.

To say “I’m satisfied…the answer is hell yes.  And I regret taking so long to get around to getting Project Big Ears on the air.

But it’s one of those things you learn (like drinking a beer after you lay a course of bricks, lol) —  If you do the fun stuff FIRST, the important stuff never seems to happen.

On the other hand, wonder how many exotic new countries I could have worked if I’d gotten to this one sooner? I try not to think about it.

Write when you get rich (or buy and S-Line for us, lol)

73 de AC7X

4 thoughts on “Prepping: Project Big Ears Part-2”

  1. The big orange box store will rent you the Bosch SDS MAX and the ground rod driving bit. If you’re like me, you’ll want to grab a few extra ground rods, and install them anywhere you think you might need one in the future. Even in rock laden soil, it’s about a 2 minute deal per rod. Forget the sledge and the hit-and-miss on a ladder. Save yourself time, energy, possible hospital trips and related, and do it the easier way while we still have the luxuries of a semi-sane society and grid power.

  2. What’s more fun? A new antenna, or a new radio? I just got an Icom IC-7300. Awesome technology! Direct RF to digital conversion. (I think it’s better than an S-line.)

  3. Do you know the natural resonance frequency of your beverage antenna? If you have a signal generator and oscilloscope, or a good AC voltmeter, there is a quick and easy way to do it using a resistive T-network. One arm of the T goes to the antenna, the other arm to the signal generator. The base of the T where the voltmeter/oscilloscope is connected. Start with 10K resistors to provide isolation from parasitic loading of voltmeter/oscilloscope. Higher resistor values are better, it depends on the voltage your signal generator can deliver. Higher signal voltage better results.

    Sweep the generator over expected range of operation and watch for maximum amplitude. Do a wide generator sweep as possible to make sure the maximum observed is the real maximum and not a harmonic mode. After observing the maximum, reduce frequency where the observed value is half the maximum. Then increase the frequency past the maximum to find half value at the higher frequency. With this information, antenna Q can be calculated, Q = Fo/(Fu-Fx) where Fo is frequency of maximum amplitude, Fu the upper frequency for half value, and Fx for the lower frequency.

    Takes a bit more manipulation to find the input impedance of the antenna without specialized and expensive equipment. If you have a “known” inductance, place it in series with the antenna and find the frequency of the new maximum. This, with the maximum frequency from the antenna without the inductance, allows a good calculation of the REAL value of the antenna impedance

    Without specialized and expensive equipment, one has to do more “head scratching work” to get the desired result. If you have the equipment, then its a “cake walk!”

    If this interests you, Have FUN!

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