To: <towertalk@contesting.com>
>Date: Sun, 28 Jun 1998 17:58:19 -0900
>From: Jim Reid <jreid@aloha.net>
>
>Aloha again from Kauai,
>
>Well, with my new MFJ-259, I am finding out all sorts of things
>about my antenna/feed line systems!
>
>Thought I would post the Z's of the various Gladiators as seen
>from here in the shack at the LMR coax input end. They look
>good to me, but I am not an expert at interpreting such. These
>taken after the various apparent losses reported in my previous
>posts to the reflector.
>
>Am a little puzzled about the rather wide frequency range over
>which some of the verticals show X=0 in the impedance read out,
>see below:
>
>TL160 Now have a lot of vines covering the vast reaches of the 126
> foot long radials; result seems to be a lowering of
> where I had set the lowest vswr frequency:
>
> f= 1.760, R=100 ohms, X=0, vswr=1.9:1
> f= 1.790, R= 82 ohms, X=17, vswr=1.7:1, lower?
>
Jim,
Sounds like you are having a lot of fun with your new MFJ259B. I
don't have much comment on the rest of your post but your TL160
measurements are not inconsistent.
The SWR for 100 ohm impedance load is down by what is probably
the amount of the line loss from 2.0:1 - makes sense.
The magnitude of the impedance for 1.790 MHz is:
SQRT((82^2)+(17^2)) = 83.7
and
87.3/50 = 1.67
so the indicated SWR of 1.7 also makes sense.
73, Eric N7CL
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