[TowerTalk] [CQ-Contest] Coax Stubs for SO2R

Jim Thomson jim.thom at telus.net
Wed Sep 9 20:41:59 EDT 2015


Date: Thu, 10 Sep 2015 01:00:26 +0200
From: "Peter Voelpel" <dj7ww at t-online.de>
To: "'Mike Smith VE9AA'" <ve9aa at nbnet.nb.ca>,
<towertalk at contesting.com>, <cq-contest at contesting.com>
Subject: Re: [TowerTalk] [CQ-Contest] Coax Stubs for SO2R

That stub is to stop interference from 20m, not to block 40m interference on
rig B!
Against 40m qrm you will need that halfwave open stub (tuned for the 40m
qrg) on rig B.

73
Peter

##  Nonsense.   A .25 wave shorted stub on 40m, is a .5 wave shorted stub on 20m,
and a 1 wavelength shorted stub on 10m.    He wants to kill the 2nd harmonic of the 40m TX
signal from interfering with his 20M  RX.   Hes doing it correctly, but why the stub doesnt
work is still a mystery.

## BTW, there is no such thing as a 1st harmonic.   Its 2nd, 3rd, 4th, 5th etc, etc. 

Jim   VE7RF



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