[amsat-bb] Solar Ham Radio Interference
normanlizeth at gmail.com
Mon Nov 21 00:36:51 UTC 2016
Blatant plug for the engineering team here:
Site overview here: https://youtu.be/sZp7xqP6F7k
Underneath the poles for RFI survey 1: https://youtu.be/n7zCSf280XI
50' away for RFI survey 2: https://youtu.be/DpwA4PoKUE4
Condx: Dipole resonant on 10m about 5' off the ground, Sweepstakes
weekend so there was a lot of activity on 20m. The RFI surveys are
trips through the upper portion of the 20m band.
Inverters producing 10kW during the test. Not sure the inverters or
panels are producing any RFI of note. Based on what I saw, there is
little to complain about. The noise floor is lower directly under the
panels than it is 50' away. Nothing lower in frequency is useful
during the day and so was ignored.
The next 20kW will be done the same way. Next year. Wife wanted a car.
Get 50kWhr per day, rain or shine. Best day is 82kWhr.
Today's yield: https://www.flickr.com/photos/n3ykf/30774099190/in/dateposted/
Last year when I did this survey the first time, the neighbor had grow
lights running. Ugly RFI. Amazing what a few words will do.
His end is here:
On Fri, Nov 18, 2016 at 8:10 PM, Robert Bruninga <bruninga at usna.edu> wrote:
> 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 at usna.edu]
> Sent: Sunday, October 23, 2016 12:55 PM
> To: Amsat BB
> Cc: bruninga at 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
> 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 at yahoogroups.com Bob, WB4APR
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