Strange Transmit Spectrum Display with Pixel Loop antenna on XVTR port

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  • Updated 3 years ago
  • Answered
With a Flex 6300, with a Pixel Loop antenna on the XVTR port, the Panadapter transmit spectrum looks like this:

With the Pixel Loop on ANT2 port I get the normal display:

The Pixel Loop antenna is wired KEY to TX, which turns off power to the amplifier.

  Has anyone seen this?  Is it affecting my actual transmit signal?

73, Javier

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Javier, KC2QII

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Posted 4 years ago

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Steve - N5AC, VP Engineering / CTO

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Official Response
This is not an indication of transmit purity. I'd have to go research the exact relay positions in this configuration to say what the cause is for sure, but the display you get in transmit is based on where the RX ends up. If it receives a lot of signal, you can end up in a mild overload condition which is what the top looks like to me. As a general rule, don't rely on the spectrum during transmit as a lot of factors, many external to the radio, can make this display show conditions more reflective of a receiver effect than a transmitter effect. You're better off to understand what is typical for your installation and investigate if you see large differences.