I did before and after testing using the big coax choke from COMTEK, and it did not help. The noise I was seeing on the 40 and 15-meter bands was still there and at the same level.
Unfortunately I was no longer able to use my Flex 6600M on 40-meters as it refused to find an acceptable match (in the past it would be about 1.5:1. Not the fault of the CMCC, of course, but an indication that my station ground is part of the antenna system, and was being isolated by the CMCC.
Back to the plain-old coax jumper, and some head scratching regarding my station ground.
