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Re: [TowerTalk] remote control of antenna switch via "wired" UHF

To: <>, "TowerTalk" <>
Subject: Re: [TowerTalk] remote control of antenna switch via "wired" UHF
From: "K0DAN" <>
Date: Mon, 23 Jan 2012 10:40:29 -0600
List-post: <">>
About a month ago someone posted links to an inexpensive RC 
TX/RX/relay-board (around $50?) and I think this is what you're referring 
to? Can't find those links anymore, would you please resend?

Thanks and 73


-----Original Message----- 
From: Pete Smith
Sent: January 01, 2012 09:18 AM
To: TowerTalk
Subject: [TowerTalk] remote control of antenna switch via "wired" UHF

I am planning to build, in the next couple of days, the couplers needed
to test this idea.  To revisit it, I have qn inexpensive RF-controlled
8-way band switch, and several people suggested that I should couple the
RF from the "remote" to my feedline, and pick it off the other end, to
eliminate path losses over the ~300 foot range.

This seems plausible to me, but as usual I'm having trouble figuring out
the specifics.  Say I take a piece of RG-59, remove the jacket and the
shield braid, and then couple the output from the remote to the center
conductor moni-match style.  Should I lay the coupling wire parallel to
the center conductor, or should I wind it around the insulated center
conductor?  What sort of total length for the coupling wire would give
best results at ~315 MHz?  Any difference in the design of the coupler
on the receiving end?

I assume I should pull the braid back over the "coupler" section - is
that right?  If I have common mode chokes (#31 toroids) on both ends of
the feedline, will it be better to have the couplers between the chokes,
or doesn't it matter, since the UHF RF will presumably be going by
differential mode?

73, Pete N4ZR

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