Hi Steve,
I don’t have a QMX, but I started with the QLG1 and my U3S tx, and the interference was to my HF rig, the FT897. Lots of ferrite experiments but the unscreened setup I never cured. Then I built the QLG2, same interference so I built it into a screened box, extensive experiments with connector filtering etc gave some improvement, I finally fitted an on/off switch so when on WSPR and all have stabilised, I could turn it off to stop the interference. This one even interfered at 2m. Then I built the QDX and used the QLG3 with the optional screen, used a short as poss connecting leads and ferrite blocks, but I still get some tramlines in FT8 and WSPR MODES if it is left on. I also built a standalone GPS enabled QRPLabs clock (QLG2 I think), but it blotted out my DAB radio when placed close by until I fitted ferrite clamps every couple of inches along the 5v wall mount PSU I use.
If I listen on 2m FM, at the same time as I use any of the kit above, I hears a background pulsing noise every second, so I assume this is the data burst. It is only at 9600 baud so I don’t know why it causes so much grief. If I run my FT896 Cat control at the same baud rate to my PC, I get no interference from that at all. It’s a mystery.
73 Ken g4apb?
