[TowerTalk] Coax stub question

[David Hachadorian]

----- Original Message ----- 
From: "James C. Hall, MD" <heartdoc at nwtcc.com>
To: <Towertalk at contesting.com>
Sent: Tuesday, May 23, 2006 8:32 PM
Subject: [TowerTalk] Coax stub question


> There was a recent article (I thought)
> about using a switch to short or open the distal end of 
> the stub and for
> what bands this would be effective given a 1/4 wavelength 
> on a particular
> band.

That was probably from a posting that I made here on 
towertalk. A 1/4 wave 40 meter stub (~23 ft) has the 
following characteristics:

shorted: Passes 40/15, rejects 20/10
open: Passes 20/10, rejects 40/15

If your station wants to operate on 80, the 40 meter stub 
must be removed. To cover all the pass/reject combinations 
of 80/40/20, you would need two stubs, one 23' and one 46', 
with the ability to short/open the ends.

Dave Hachadorian, K6LL
Yuma, AZ










































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