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Re: Reflection?

I am assuming you have replaced your test leads to rule them out. With a period of 42Mhz, the mismatch is only 10' or less away. Is the test point directional or resistive? Resistive TP's can cause standing waves with short periods. If the TP is only 20dB down I would follow cableho's advice and try sweeping with a 10dB pad. If that dos'nt fix the problem I would rule-out the connector on the output. Try sweeping off a tap adjacent to the amp if you can find one. I have seen systems that were forced to cut in taps after every amp so they could sweep the system.

Just in case you or anyone reading this is interested, you can measure the distance to the fault causing a standing wave by using the following formula: Distance to fault (in feet) = 492 times the velocity of propagation of the cable divided by the period of the standing wave(distance in Mhz between two wave peaks) D=492(Vp)/f In this case assuming the Velocity of propagation was 87% D= 492(.87)/42 = 10.19' Just remember this figure may be longer than actual due to variables inside the amp.
Good luck
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Posted in reply to: Reflection? by uppity prick
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