OK, Topbanders, I have a mystery I am trying to solve with my inverted L
Last December, I put up ¼ inverted L (vertical was 80 feet, horiz was 52
feet). Remote coupler at the base (CG3000 PiL). It was cold outside and
I was travelling a lot, so I only put down three radials?each 130 feet. I
wanted to see what would happen, establish a baseline from which I knew I
could improve with more radials.
I have 200 foot of lowloss coax from the shack, but I still don?t want to
give up any of my 100 watts to SWR losses in the coax?so I use the remote
coupler.
Well, the results were astounding on 160 for my first attempt?45 countries
with 100 watts, including lots of EU and a 4X at his sunrise. I also heard
and worked some excellent DX on 80 with it.
In March, we had a horrific windstorm and the wire broke. So I restrung it.
Since putting it back up, I was unable to get the remote coupler to tune the
inverted L on 160. I tried changing the length of the wire to vary the
resistance/capacitance to see if that would be more couplerfriendly. I
used lengths from 114 feet, 132 feet, and 174 feet. No success. I added
four additional radials. Still no tune with the remote coupler.
So I decided to start a serious investigation. Using an MFJ259 tonight at
the base of the antenna, I see 1 ohm of resistance and 400 ohms of reactance
at 1.8 MHz, for a length of 174 feet of wire. At 3.5 MHz, I see 25 ohms
resistance and 85 ohms reactance.
>From the readings, I have the following thoughts.
* I would expect a higher resistance with the longer wire above ¼
wavelength on 160, say around 100 ohms, because an endfed ½ wavelength wire
should be seeing 5000 ohms. Why the low resistance?
* I would expect a much higher resistance with the wire on 80 meters,
maybe 500 ohms. Not 5000, because it is NOT a half wavelength endfed, but
certainly higher than 25 ohms
* Even with just 6 radials, I should see 10 or 20 ohms of resistance
on 160
Any assistance/guidance appreciated. I have time before 160 season starts,
but I want to be READY! Thanks in advance
Mark Lunday
WD4ELG
wd4elg@arrl.net
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UR RST IS ... ... ..9 QSB QSB  hw? BK
