I've just recently gotten on 160 with something resembling
N5KO's "Home Depot Special." I'm thinking about modifying it to
a more conventional inverted L and wanted to poll for ideas
and thoughts on the subject.
Since we don't have 100' sequoia's here in KY, the tip
of the 1/4-wave vertical element is only about 70 feet in the
air. So the "vertical" is below 45 degrees off the ground.
I've got 4 1/4-wave radials (counterpoise?) run from about
6 feet above ground at the base, going down to ground level
as the go out into the yard. None of them are perfectly
straight, a couple have to wrap around other objects for a few
feet. One goes out 50 feet or so, then loops around some trees
in one corner of the lot.
The SWR is less than 1.5:1 from 1.80 to 1.91 MHz. The dip is currently
at 1.835 with what appears to be 1:1. From what I've read, this seems
fairly broad, so I'm guessing I have a lot of ground losses. The SWR did
change from Sunday night to Monday night. It seemed to "shorten"...enough
to move the dip up about 40 KHz. I didn't change anything though...the only
noticable difference is that the ground was frozen last night, where
it wasn't Sunday night.
The antenna has managed to work a little DX over the past two nights (I just
put it up Sunday). Last nights haul: IT9, DK6, F5, EA3 and VP2. I heard
OK6, but he couldn't hear me. I received 559 on all of these, and it usually
took the other guy a few trys to get my call. This feels like further proof
of poor effeciency (ground loss). With only 100 watts, I can't afford to loose
much!
Here's what I'm thinking about doing:
1) Make it into an Inverted-L. A second, nearby tree should
hold the vertical up to about 60 feet or so, then run over
horizontal to the current support.
2) Lenghten the wire from 130' to about 170' and match with a
series capacitor. From what I've read this should
improve effeciency by moving the maximum current position
up off the ground.
3) Forget the long elevated radials, and put them on/in the
ground. Also from what I read its a better trade to have
more shorter radials (1/8 wave) than a few long ones. I'll
probably put in 16-20 (1/8 wave) radials instead of the 4
1/4-wave ones. And make them as straight as possible. Plus
the elevated radials get in the way, especially when mowing season
starts.
4) Put up a couple two-wire beverages for receive. I'm not sure I
can get to the full 580 feet (more like 400-500 ft range). Is
this a problem??? Right now I can hear more than I can work so this
isn't as critical as improving the transmit antenna. Also do
these need to be perfectly straight, or can a slight bend around a tree
be tolerated?
So what do you think????? Am I on the right track??? Am I missing
something? Any other ideas?
Thanks in advance and 73's
--Lee
PS - I used wire with "purple insualtion" for the radials....does this
add to the kharmic balabce???? :-) (Hey it was a little cheaper).
---
Lee Wells - KT4ZX
leewells@lexmark.com
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