FW: [TenTec] TenTec for 160M -Reply

[Alex Mendelsohn]

>What antenna does work for 160, that a city dweller can erect?  Say on
>a 50 by 100 lot.
>


In recent years, I put up a pair of verticals, spaced roughly 1/4-wave 
apart, and ground mounted, for 75 meters. They're designed to work at 3.775 
MHz, and are relay controlled to switch the pattern either to the West, the 
East, or broadside (N-S). An 80-degree phasing section is controlled by a 
pair of dc relays to accomplish "swinging the beam."

In any case, when i first started on this project, I used a pair of trap 
vertical antennas. One was a Hustler 4BTV and the other  a Cush Craft AVT-4.

I added a top loading coil to each (that's a better way to achieve resonance 
on 80 meters than with a base loading coil; it's more efficient). I also 
used old music stand (!) aluminum to make top loading capacitors. I built a 
little resistance bridge to use with my grid-dip oscillator to measure the 
feedpoint resistance and adjust the verticals to resonance by pruning turns 
and bending the aluminum tubing in and out.

Well, they worked quite well---even though only 23 feet high. To be fair, i 
had 1,500 feet of wire under each vertical, for a total (now) of over 3,500 
feet of radials on the ground. I love junk wire.

Last year, I replaced the top loading affair with full-sized wires held 
aloft with halyards in the trees. Although this system is now theoretically 
less lossy than the top loading coil arranagement I used to have,  I can see 
NO DIFFERENCE in performance over the short antennas! I make this conclusion 
after a winter of operating.

There's simply no reason why a short antenna won't do a respectable job--if 
you pay attention to how it is constructed, and, in the case of 
ground-mounted verticals, if you have a decent counterpoise array. BTW, 
radials make vertical antenna projects BIG antennas. It takes a fair amount 
of turf and a lot of work to lay the radials. There is an up-side to this: 
the radials don't have to be quarter-wave in length. They can be as short as 
0.1 wavelength.

Another point: I use the open-wire feeders on my 80 meter doublet tied 
together as a vertical. This so-called Marconi is worked against the 
aforementioned ground system. It works quite well on 160 meters.

In the past, when I was a cliff dweller, I often used end-fed very short 
wires, and worked them against steam pipe grounds and water pipe grounds. 
They always worked surprsiingly well, putting me on 80 meters with wires as 
short as 25 feet.

The conclusion? Do NOT feel constrained by short antennas! Get 'em loaded, 
and get on the air---and work your share of DX! Even with QRP.

Vy 73, AI2Q, Alex in Kennebunk, Maine  .-.-.

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