NEW ISSUE:
Previously QST and my emails discussed the rise in the noise floor from home solar and my suggestions to avoid purchasing a system with micro-invrters or elecronic "optimizers" on every panel on the roof, and stick with the wuieter or easier-to-fix all DC wiring and central inverters.
THAT’S NOT ALL! It was pointed out at the ARISS meeting this weekend that one must also watch out for their NEIGHBORS! That is, if you want to keep your clean noise floor for your own hamming and your own solar, you must also be vigilant of your surrounding neighbors.
The time to make friends so you can guide their future investment is NOW, well in advance before they make an irreversible decision.
Ill try to remember to go out and see how far the noise radiates from some of the other solar panels in my neighborhood. Although my DC system with central inverters is much quieter, I should go out and see how far beyond these houses, the various system's interference can be detected.
Bob, Wb4APR
-----Original Message----- From: Robert Bruninga [mailto:bruninga@usna.edu] Sent: Sunday, October 23, 2016 12:55 PM To: Amsat BB Cc: bruninga@usna.edu Subject: Solar Ham Radio Interference
Not Satellite related, but people often ask about any RFI from my solar arrays at home. Interest stems from an RFI issue in April QST and my letter in Sept 2016 QST.
Well, FINALLY, the jury is in. For the first time since installing solar, I finally got all my full-sized dipoles up in the air again. And listened with the arrays on and off.
Yes, I have inverter noise about 12 dB above the noise floor every 38 kHz on 80 meters,. But couldn't really find anything on 20 meters. I did not do a thorough search, but enough to finally say, "yes, there is some noise..."
I post this because my 16kw of arrays are conventional series string arrays and much quieter than the "optimizers" on every panel all over the roof noted in the April QST article. I always thought my string array was quiet, but now I have some data noted above. This could easily be fixed with some clamp-on ferrites down in the basement on the wires going into the inverters...
But for my rare HF operating, the solar AC disconnect switch is about 3 feet from the kitchen door. Easy enough to pull if I want HF silence. I could also install a 40 amp disconnect relay from a switch in the shack... But with my rare operating style, I'll probably do nothing. Of course it is perfectly quiet at night ;-)
It took me 6 years to get around to this test, so don't hold your breath waiting for me to add some clamp-on filters to the inverter wires and see what that does.
For those into solar, come join us on SolarDIY@yahoogroups.com Bob, WB4APR