[aprssig] Fwd: The end of daytime HF?

david vanhorn kc6ete at gmail.com
Thu May 3 23:06:48 EDT 2018

I work in a 1 story building which is covered in solar panels. The
inverters are mounted on the wall outside my lab.  I design avalanche
beacons at 457kHz. I am trying to detect signals that are barely there.
 While the solar panel is my "go to" culprit when I see interference (rare)
we have never actually had detectable noise.

That said, I agree that this is a potential issue for the reasons you
raised.   Perhaps we can interest the FCC on enforcing ALL electronic
imports like they are supposed to already be doing. This would align with
the trump agenda and would work in favor of us domestic companies who do
the hard work, make quiet products, and actually get them tested in a real

My designs are so quiet they are almost unobservable in testing but one of
my competitors is noisy enough to deafen any other unit within a meter or
so when it is in receive mode.   Personal electronics are a constant
problem for us because of the high noise levels.     The "smog" from all
these devices is also destroying AM broadcasting .

What if the FCC actually grew some teeth and did their job?

On Thu, May 3, 2018, 8:22 PM Robert Bruninga <bruninga at usna.edu> wrote:

> I don't want to be an alarmist, but we need the Hams with the proper
> knowledge to get involved in this disturbing news.
> The National Electric Code now requires electronics on every module of a
> solar array communicating  via signalling on the DC power lines to assure
> EACH pair of panels can shut down independently.  This is to make all
> possible faults never allow more than 80 volts anywhere in the system.
> This is effective 1 Jan 2019
> This is the nail in the coffin of simple DC series string arrays which are
> the quietest systems and almost demands microinverters or optimizers on
> every panel.  Refer to the QST article a few years ago about how disastrous
> optimizers are to RFI and HF operations with modules all over the roof..
> Here is the Solar news:
> https://solarbuildermag.com/bos/nec-2017-module-level-solar-system-shutdown/
> Also, what is going to happen to an array that has signaling all over it
> in the near field of HF?
> Although you can avoid it by going solar before then, you may have
> problems when your neighbors go later.
> I hate  to be an alarmist but we all know what happens when ham radio and
> commercial systems are incompatible and even though Ham radio might be in
> the right, we are only 1 in 600 and no one is going to side with us.
> We took on broadband over power and squelched that dumb idea, but now this
> has the potential for equal demise of Ham radio.  It should be fixable, but
> we also know that there is high competition in the solar market and the
> modules that are made the cheapest  will be popular and will likely not be
> adequately filtered.
> Sorry for posting to the APRS group but it is the only HAM email reflector
> I subscribe to besides AMSAT..
> If nothing else, we need to find out what systems are terrible emitters
> and nip them in the bud.  Maybe all it takes is driving by solar systems
> you see and turing on your AM radio on a weak signal channel and seeing if
> the background noise peaks near that home.  But also it has individual
> peaks, so it might also be nice to tune around too find the max and then
> check the range.  I find the noise can go hundreds of feet along the power
> lines....
> You cant miss  em... just sounds like a 60 Hz buzz on all the harmonics of
> the inverter switching frequency.
> Bob
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