Tom, Thanks for the details on the "Z" for TB. On a related matter I
have been looking for comparisons between a "L" and a "T" firmly
believing that a "T" would be better as in 65' up and 135' horizontal
fed in the exact center. However there are so many TB'ers using "L"
rather than "T"s which begs the question....why? You need two supports
for the "L" but how much do you gain by converting this to a "T" with
even a modest ground plain of 6-12 radials? Or is it just a matter of
convenience and lot size? Here on 80 meters I use a "T" with a 50' drop
wire and a 20 foot center fed top wire. Sloping off to one side of the
top is a 34' drop wire separated with some Dacron rope so the 40 meter
section meets the same feed point. And this makes for a very good
performing 80/40 meter vertical. At times on some DX it outperforms my
80/40 meter dipole at 70 feet. The ground system is 20 radials made
from Cat 5 cable laying on the ground with the feed point and ground rod
next to the the septic system tank.
Again my question: How much better is a "T" over an "L" on 160?
Herb Schoenbophm, KV4FZ
On 2/16/2015 6:23 AM, Tom W8JI wrote:
Rick, I think it had more to do with getting something out of the
shack window with the tuner inside. I also think it had more to
getting the current maximum at the top of the pole. The OT's used to
tell me they just taped a #47 bulb and a small loop of wire at the
top and fed some power 20 watts or so at night and then trimmed the
far end for maximum brilliance to try and get the current maximum at
the top of the slant wire. With some vertical component and
horizontal cancellation I can not see how this was a *bad* antenna
for beginners on TB.
That was an antenna popular in the early 1960's, I tried one myself
back then.
It appeared everywhere as an improvement to a vertical or inverted L
antenna. It was ideally out 65 horizontally, up 65 vertically, and
out 130 horizontally. If the vertical section was lower height, the
low horizontal was extended.
The idea was to get current at the top of the vertical section, and
enough length on a horizontal single wire feed to make it a 1/2 wave,
but it was a bad idea. Mine was way down in signal strength locally on
groundwave over a base loaded vertical. It improved greatly when
turned into an inverted L with current maximum at the base.
As Rick says, it acted more like a bent dipole with one end 6 feet off
the ground for 70 feet or more.
73 Tom
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