I am seeing some strange artifacts when I run a spectrum scan on 160M. I see this on both the input and output of the filter. The scope trace shows a perfect sine wave so I suspect that this is some sort of error on my part in setting up the scan. The input run is around -10dbm directly tee’d off the input to the amp. The output is from a tap on the output of an amplifier that is putting 50W into a dummy load.
The 80M scan is what shows as a more normal run. (I don’t know how to remove the spikes at 12 and 31. Those show up on all of my LPF runs, not just 80M.
I am guessing that I don’t have the ref set properly? I am at 0db.
John – W9JSW