"Excess power detected on receiver"

  • 1
  • Problem
  • Updated 2 months ago
Operating Flex 6400 on Win 10 Home v1803
Smart SDR
Simple all band vertical antenna and only antenna connected to Antenna 1 port on 6400

Plain jane setup.

Low and behold I go to make a CW contact and for each tap of the paddle I get a cascading series of Smart SDR error messages

"An Error Has Occurred"  "Excess Power Detected on Receiver (>+20 dBm), transmitter has been unkeyed and receiver disconnected to protect hardware" 

What the ....  there is no other radio transmitting .. this only happens when I hit the CW key and attempt to transmit .. this is a head scratcher as I don't know of any changes to the config

Tim ... HELP ... I'm unable to transmit ... rx only ...



Photo of Ed W2MKM


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Posted 2 months ago

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Photo of mikeatthebeach .

mikeatthebeach .

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Try Downloading to a Lower Version of Software and see if it happens
Then Upload to a Higher Version and see if still there 
73 Mike
Photo of Ed W2MKM


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Thanks Mike .. but is this a known issue?  I've successfully worked CW on this radio since I got it ... and have updated to v2.3.7  some time ago .. I've only come across one other issue with the same description and it was when there was another radio operating nearby ... this is not the case ..

This is a new one for sure

Respectfully the procedure you note seems like "not sure .. but give it a try" ..

Photo of Bill -VA3WTB

Bill -VA3WTB

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It is not a version problem.
Do a factory reset, and bring back your profiles that you saved.
Photo of N8SDR


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Sounds to me like a lot of common mode, Is there any balun on the vertical? how is the vertical grounded? can you try winding a loop of coax before the radio , 6-8 turn in 8 inch loop or so. 
Photo of Craig Williams

Craig Williams

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For me it always turns out to be a bad PL-259.
Photo of Ed W2MKM


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Certainly a solution I’ve considered but this has been a stable setup for some time.

This occurs with little or no output power.

Seems like a mouse turd floating around the memory of the 6400 and I will try a factory reboot and go from there

I will advise ASAP