At 06:02 PM 5/23/00 -0500, you wrote:
>I have a rack mounted amp in the basement, under the hamshack and it has a
>rack mounted Bird hooked to it. I wanted to watch the output from the shack,
>so installed another dual section bird line section, and ran some shielded
>cable upstairs. About 15 ft max.
>Didn't have any cables made up that long, so spliced together 3 old Collins
>patchcables with RCA plugs per lead,and ran them to the dual needle Weston
>meter upstairs, which is mounted in a Bud box.
>No problem, everything as it should be. Then made and installed 2 nice
>looking jumpers the correct length from RG174, and everything got goofy. The
>meter barely reads anything.
>
>Cables check AOK with an Ohmmeter and have about 1.5 Ohms round trip
>resistance. The capacitance is quite high on the little coax though.
>
>The Collins cables have a little lower resistance, but much lower
>capacitance.
George: I see two problems. First the signal from the Bird to the meter
is 30 microamps or less and the phono plug (or any other connector) needs
to be noble metal ( gold, silver, etc) for it to be reliable. Second a
high C in the cable going to the meter will change the pick up frequency
in the cavity. Best to use low cap shielded network cable if you are
concerned with rf pickup.
de Norm N8RGR
>Why would this be?
>
>What would you have to do to monitor a real remote amp, say 300 feet away?
>
>Thanks for your thoughts on this.
>
>K0FF (George)
>
>
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