Walt - thanks for the ideas.? C52, C55, L10 C61 and L12 all checked out good and within tolerance.? The spectrum on 15 looked as bad as on other bands.? Next I checked the 6.250 trap again and found that while I had adjusted it for a minimum, the slug was at the upper limit of travel away from the coil.? I checked C59 and found it a bit high at 35 uF, so replaced it with a 32 pF mica and now I get a true null much lower than before.? Even with all the noise present, I was able to get much better sideband suppression than before.? So really need to find the noise problem.? I pulled V5 and checked the purity of the CW and AM signals - as good as it can be with no noise or ripple at all.? I think V1 and V2 are good - scoped a sine wave all the way to the plates of V5 and it was still a nice sine wave there.? I'm going to clean the switch contacts again.? When I look at the output of T2 while feeding a 1,000 Hz tone into the mic jack in SSB mode, the output wave there looks good.? But, the? signal has an unstable look at the grid of the first mixer.? Of course it's going through a couple of switch wafers and runs of coax to and from the RF level control on CW and AM.??
Floyd
Floyd - K8AC