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On Tue, May 9, 2017 at 11:49 AM, Greg Stahlman [email protected] wrote:
Problem is, solar MFGR’s are exempt from Part-15, BUT, the operators are not! At least that’s the way I read it.
100uV/M is a LOT! Especially when trying to run weak signal stuff! My neighbor’s is about 18db over night time noise floor!
I heard good things about “Micro Inverters” vs the more common “Optimizers”, which are basically a DC-DC converter on the back of the panel, and they were right! I had a 7KW system put on my roof but demanded they use Microinverters and I hear NOTHING!! Very quiet!
The Optimizers are a HUGE nuisance from 80M through 6M and even on 2M.
Regardless if they fall under the 100uV/M, the main rule of Part 15 states simply “…must not cause harmful interference, even if it results in the improper operation of the interfering device.”
73
From: AMSAT-BB [mailto:[email protected]] On Behalf Of Robert Bruninga Sent: Tuesday, May 09, 2017 7:30 AM To: [email protected] Subject: [amsat-bb] Solar RFI?
RFI from Solar?
With solar now cheaper than coal, solar is exploding in to neighborhoods with favorable progressive policies.
But, they can produce lots of RFI with significant impact on Hams operating HF.
With 16 kW of solar on my roof, I feel in a good position to be proactive in documenting the overall impact of solar on HF operations.
We’ve seen QST articles on the very high RFI levels from solar systems that use microinverters and optimizers located at every single panel on the roof which are a nightmare to filter, while string inverters are easy to filter at the one location on the ground.
My thoughts are to come up with a standard test that Hams near solar installations can do to document any RFI. Although none of us will have standard calibrated antennas or receivers, we can at least make comparative measurements to background noise levels. Either with the array on and off or between day and night at a fixed distance from the array.
I believe the part 15 limits for unintentional radiators is for 100 uV/m at a distance of 30 meters (100 feet). On a 1 meter portable antenna I calculate that is equivalent to 36uV or within a dB of S9. That’s a lot of noise (if I did that right)…
And if it was a full size dipole say on 20m, then the allowable noise would be 20 over S9 (again, if I did that right) Wow.
If anyone wants to submit measurements Ill collect them.
My suggestion is to take a portable HF rig (FT-817 or TH-F6 or TH-D74) and an approximate 1m whip antenna and report at 100 feet from the array, the S readings with the array on and with it off (or day vs night).
I welcome more expertise in this area. Although this is not an AMSAT issue, this is the only email group I’m on that might have people with those easy portable HF radios.
Bob, WB4APR _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
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Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb