The last few days following our effort in the Cal QSO Party has been pretty interesting from a noise redux perspective. With Chuck here we managed to further quiet my nasty 60 Hz buzz from the FIOS battery backup charger. That alone resulted in a 2 S Unit reduction of my noise level on 20 Meters. The messing about with Gas Meter and AC cooling copper lines took out a nasty intermittent that really wiped out 30 Meters.
This afternoon on our regular CW Practice Sked, Chuck asked me how much the total effort had yielded to date all up and in WRT to noise reduction? To begin with, when I first started noise hunting I had no transmit feedline chokes, no ferrite around anywhere and I was using an inherently noisy antenna -a vertical. From that setup to current has seen a vast improvement. Just examining 20 Meters, I started with an S Meter reading of S-9 plus 10 DB. This measured in AM mode at 9 Khz bandwidth with Preamp 1 set to “On”. Today that reading is S-5 with the same set of measuring parameters. Along the way I calibrated my S Meter by building an Elecraft Xtal Calibrator and a Step Attenuator kit, also from Elecraft. I measured my S Units at 3 DB per step or 3 DB between S-1 and S-2 etc all the way to S 9. Above S-9 the DB measure on the S Meter compared favorably with the Elecraft Step Attenuator. Using 3 DB per S Unit I come up with a measured difference of 22 DB change in noise levels here based on active noise searching and antenna changes. Unfortunately, I did not note how much change the Vertical to Horizontal antenna switch made. All in all a respectable change up in received noise hereabouts.
When running a station with low power or low antennas it is doubly important to reduce the local noise cloud-that is whatever is in your control. I find that it has been well worth the effort.
Thanks for reading my Blog. Best, Chas W5PG