I have encountered an unusual situation with my new Flex 6400 received last week. Please bear with me, my explanation is a bit complicated.
My wife is now using my old 6300 and we both work mainly cw. Our stations are in separate rooms, about 40 feet apart. She uses a 20 meter dipole/40 meter inverted vee combo with a single feedline at 30 feet and works only those bands. Untuned SWR is below 2 to 1 on both bands.
My antennas include an 80 meter dipole/40 meter inverted vee fed at 50 feet; a 160 meter inverted L, 60 feet vertical and 100 feet out; and, a Classic 33 tribander at 45 feet. Untuned SWR is below 2 to 1 on all bands. We have operated this antenna configuration for over 2 years with her running 100 watts on a Kenwood TS-440SAT and me running the 6300.
We frequently work cw at the same time for a weekly CW event. Prior to receiving the 6400 I had never encountered an error message regarding “Excess power detected on receiver” using the 6300 during our operating. I typically start on 80 meters and she starts on 40 meters. During our first session with the new Flex stations configuration, operating on 80 meters, I immediately started receiving the Excess Power Detected message on my 6400 computer with her every dot and dash sent on 40 meters. I could not continue operating until the last error message was cleared and she stopped sending.
My investigating has revealed the following: With her 6300 on 40 meters cw, a single 30 wpm ‘dit’ results in my 6400 producing the error message, with a new error message for every dot or dash sent, but only when I am connected to my 80 meter dipole/40 meter inverted vee combo. I found I get the message regardless of the band I select from 160 meters to 6 meters when she is transmitting on 40 and I have the 80/40 antenna selected. I have no problem whatsoever on any band when she is on 20 meters.
If I switch to my 160 or tribander antenna, with her on 40, I have no problem whatsoever on any band. I tried reversing our antennas, put her on the 80/40 combo and me on her 40/20 combo to see if my sending on 40 would affect her 6300 receiver. It does not. My 80/40 combo is approximately 100 feet from her 40/20 combo and within 20 degrees of parallel.
I tried a different computer running SSDR on our lan, and a
wireless notebook on the lan, with the same results. However, when I tried my Maestro I had no
problem with interruption.
I am at a loss to explain this phenomenon. It seems that there is some circuitry in the 6400 that is extra sensitive to a 7 mHz signal when running SSDR 2.1.33 when I am receiving on any band while using my 80/40 antenna. I also tried SSDR 2.1.32 with the same results.
Other than this issue, I am very pleased with the 6400.
Any comments or suggestions will be appreciated. Thanks.