Panadapter RF Pumping

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  • Question
  • Updated 5 years ago
I've got an interesting thing going on in my panadapter. With or without a slice the RF signal goes up and down continuously at about 3 dB. This more prevalent 20 meter and above bands. 40 meters doesn't seem to be doing it. Does anyone know what could be causing that. It would be interesting to know.
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Bob G W1GLV

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Posted 5 years ago

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W4EY

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Suggestion: If you have an external RF Power (Watt) meter between your FLEX and the antenna, see if the FLEX is generating RF. If the FLEX is causing the 3db RF Signal, you should see a slight movement on your external RF meter. If it is not the FLEX, it is possibly your computer generating harmonics from the internal motherboard. I had the same type of this problem with RF signals generated on the Panadapter screen until I added RF Chokes to all my computer and FLEX interface cables.
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Bob G W1GLV

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Installed a bunch of toroids and the problem disappeared. Thanks
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Al K0VM, Elmer

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Does it still go up and down with no antenna connected?? It could be a local noise source external to the radio.

AL, K0Vm