Hey Tim,
Not yet.? I was tracing all the paths on the LPF control board to make sure I didn't have a problem with one of those 0179's.? I found a problem with the SWR xfmr in the tx path, so I fixed that, it had cut off rf output to 20W PA.? I put my nanoVNA on the antenna and got a good result on both RX and TX to and from RF board connections.? This was with everything installed.? This made the pulsating audio much better too.? When I pump several mV I/Q into the RX input on main, I get a good signal but the noise is still there.? I had replaced the ADC and resoldered all the SMA's on MAIN but no change.? Main is not generating noise as the noise goes away when I pull the RX I/Q in cable (silly, but I'm looking for the noise source).
So what I saw was that raising the RF gain raises everything and increasing RX attenuation reduces everything.? I did do an RX CAL as recommended but no change.? I still need to look into that a little more.
I have a single point ground, so I don't think there's a problem there.? I haven't hooked up a sig gen with a bunch of attenuators to see what the sensitivity really is. I need to get out of the basement and hook up to a full up antenna (in the garage!) and a good ground.? I could easily pick up W1AW on 40M in the basement with my V11 so I'm determined to get this figured out for the V12.? I don't have a cover on my case yet (metal chassis) but I have a hard time believing that noise is getting in given that all the connections are shielded.? I saw some traffic about noise coming from the display, but I waved my hand in there and there was no change in any signal.
I need to rearrange my board positions which would shorten the power lines, coaxes and the BANDS cable.
Hope is not a plan, but I'm hopin'.
Mark
KU3O
