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Old March 1st 08, 05:26 PM posted to rec.radio.amateur.antenna
Ian Jackson[_2_] Ian Jackson[_2_] is offline
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First recorded activity by RadioBanter: Nov 2007
Posts: 568
Default Coax Switching Boxes (receive only)

In message a4gyj.2405$dB.986@trnddc01, Dale Parfitt
writes

wrote in message
...
Bob,
Receivers just aren't as 'picky' about switches as transmitters are,
so almost anything would probably work just fine. If you're into
making things instead of buying them, a look in the junk box would
probably be profitable. If not, then ... whatever grabs you.
- 'Doc

The one parameter receivers are "picky" about is port-port isolation.
Switches made for HF switching will likely have very poor port-port
isolation at VHF and above. The result is the receiver hears the selected
antenna and some of the unselected antenna. This may or may not be a
problem.
Dale W4OP

A decent cable TV A-B switch should have an isolation of at least
something like 40dB at 870MHz. [I think I measured an old Jerrold switch
as being around 70dB.] While probably less at 1.3GHz, it's probably
still sufficient.
--
Ian