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Fw: Topband: Inverted L for TX

To: <topband@contesting.com>
Subject: Fw: Topband: Inverted L for TX
From: w8ji at contesting.com (Tom Rauch)
Date: Sat Mar 29 16:23:54 2003
>  > Your trouble may be that the MFJ259 usually will give erroneous
readings on
>  >160M because of BC station pickup on the antenna. That meter is not
useable
>  >at my QTH on any 160M antenna.
>
> I have had this problem with ALL soldid state instruments used on my 160m
> antenna.

If you have a problem with RFI, it is antenna size (system) related....it is
not related at all to the dial setting of the analyzer.

The problem centers around the fact virtually all analyzers use
non-frequency selective detectors. He did say the antenna tested OK on 80,
which rules out an RFI problem with the antenna.

You can test for this problem by going into the freq counter mode of the
259B or 269, which shuts off the local oscillator. If you see any reading on
the SWR meter the reading is corrupt.

I can't recall the antenna description, but as I recall it sounded to me
like the antenna described would not have a reasonable SWR on 160 with the
addition of a simple series capacitor. It might require a multiple-component
matching system, or a change in length.

73 Tom

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