I would expect it to work OK with 75 ohm cable. An open-circuited 1/4 wave
line looks like a short at its sending end and you would be looking for a
null as the line reaches a 1/4 wavelength, so I would expect the method to
work fine with 75 ohm line. In fact, the 50 or 75 ohm line, if we consider
it to be lossless would be operating at infinite VSWR so I wouldn't think
the modest difference in characteristic impedance would make any real
difference.
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of
mapa50@windstream.net
Sent: Friday, February 14, 2014 12:18 AM
To: topband@contesting.com
Subject: Topband: Palomar R-X Noise Bridge
I have a question about using the noise bridge. I have used it cut stubs to
1/4 wavelength using 52 ohm cable with no problems. I now need some stubs
using 75 ohm cable which I have on hand.
Will the same procedure work for 75 ohm that works for 52 ohm cable, or
will the different impedance need to be accounted for. I started to cut
cable and this question came to me. My first thought is that it will work
fine, but I am not sure. I did some searches on the web but found nothing
about it. Any help would be appreciated.
Thanks, Pat Armstrong
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