I'll keep this as non-political and non-government as I possibly can.
However, references to existing rules are reality.
QUOTE (from Dave Crawford's latest email): Treat them (wal warts and
SMPSs) as intentional
radiators rather than unintentional. In other words,
assume they are going to radiate, no
matter whatever else you do.
I'd like to politely point out that the regulations already in place don't
require changing wrt to Part 15 devices (unintentional radiators) and most
other aspects of CFR 47. If the regulations already in place were
enforced, the problem would not be so evident. ARRL (which is sorely
underfunded) is doing their best for us amateur radio operators in this
respect. Much of their efforts are not visible to the average amateur, but
are quite evident within this group* (Ed Hare, et. al.). Again, no
regulation emission limits will eliminate all RFI to amateur radio
operators. The levels of RFI back three or four decades ago were quite
acceptable. I've been licensed going on 65 years and write from
well-remembered experiences. No doubt the "digital revolution" has raised
the level of RFI to an intolerable level especially if one resides in any
of our large cities. Again, if the rules and regulations already in place
were enforced, we wouldn't be in this predicament. The rules and
regulations to solve this "come lately" problem already exist.
Specific RFI problems which have precipitated this RFI explosion in recent
decades are:
1) Wall warts (these days, they are all switch mode power conversion units
with little or no
consideration to EMC/RFI).
2) Virtually all SMPSs (see #1), embedded or stand-alone.
3) Suppliers of completed products with embedded SMPSs (Existing rules and
regulations make it
clear the supplier of the product is responsible for the final EMC/RFI
solution - this is a statement
of fact.).
4) Any and all electronics containing digital circoitry.
5) The entire home solar power industry. Here, ARRL has made major
strides with Solar Edge and a
few installers. We need far more visibility of the problem from
grass roots installers to the
designers of these systems! Awareness of the problems is a necessity!
6) China (won't elaborate here, but all of us EMC/RFI engineers are
acutely aware of the problem.)
7) Exemption of all home appliances (yes, a rule change is required.)
8) Customs (allows "components" through with no attention to EMC/RFI -
yes, this is a rule change)
7) What have I missed (do I dare, once again, mention enforcement of
existing rules and
regulations?)
IN SUMMARY: Any and all digital electronics and switch mode circuitry.
* ARRL should offer some regular presentation in its publications (QST, On
The Air, QEX, and possibly Contest Journal) on its efforts taken regarding
ongoing EMC/RFI efforts at the League. At present, there are none. This
lack of visibility gives the average amateur the impression that the ARRL
is totally uninvolved in this problem. That could not be further from the
truth. ARRL has a highly capable RFI/EMC lab and is highly involved with
the problem.
Hopefully, I've kept government and politics out of this response. I
tried.....
Dave - WØLEV
On Sun, Jul 28, 2024 at 5:18 PM David E. Crawford <dcsubs@molniya1.com>
wrote:
> While the admin admonitions against "politics" are well-taken, the whole
> process of change will be inherently political. But it can and should
> be done without denigration, including discussions within this forum,
> which I believe is the intent.
>
> Human nature brings a certain inertia to the administrative state where
> the authority lies for the solution of these issues. One must get them
> "interested" in the process first, and the NAB and ARRL are indeed the
> entities best situated to get the FCC's attention in the US -- if not
> them, then who? Since electronics are a world market, the ITU and other
> bodies enter the equation too. Change in this realm is hard, but
> please don't let anyone off the hook by declaring it "too hard" on their
> behalf.
>
> On the technical side of things, the cheap switcher supplies now found in
> or on everything are some of the lowest hanging fruit. Part 15 put
> down roots before those were ever invented, now the world is different,
> and it needs an update. Some ideas about switcher changes that could be
> made (as in mandated):
>
> Treat them as intentional radiators rather than unintentional. In other
> words, assume they are going to radiate, no matter whatever else you do.
>
> Allocate them some (= very few) frequencies similar to what is done with
> ISM devices. I don't think the ISM freqs themselves are good
> candidates because of the QRM that ISM devices could suffer.
>
> Put some strict freq stability and harmonic content limits on that
> radiation. So, instead of wandering noisy blobs, we have multiple, clean
> CW
> carriers sharing a single or very few strategically-chosen freqs, and
> therefore much easier to work around. And they can put out reasonable
> levels of RF on those freqs without it causing problems to others.
>
> Pay attention to the conducted emissions, not just the radiated, and put
> strict limits on them, so that some load device receiving a "signal"
> from a supply doesn't turn a clean signal into a dirty one and re-radiate
> that. Or, that a long power cable doesn't become a radiator outside
> of the supply-radiated RF limits either.
>
> Stop treating the supplies as "components" buried in someone else's
> hand-waving qual paperwork, but treat them as individual devices requiring
> qualification before they can be used.
>
> A lot of these supplies are based around canned chipsets now -- how can
> their designs be influenced to help mitigate the dirty RF problem before
> they ever see a host device?
>
> ...
>
> These general concepts can really apply to just about anything electronic,
> not just switchers.
>
> The low frequencies really are worth recovering, especially if we someday
> find ourselves without a functioning low earth orbit comm capability
> due to military conflict and we need the terrestrial/groundwave bandwidth
> back.
>
> Best regards to the group.
>
>
>
> On 2024-07-28 07:57, Hare, Ed, W1RFI via RFI wrote:
> > <While getting the FCC to change may be hard, I think we need to try.
> > Just because it is hard does not mean we look away. If we had that
> > attitude with the moon I guess we may never have gone there.>
> >
> > I agree. My comments were not intended to say that "we can't do it,"
> but that changing the rules is probably the most difficult – and time
> consuming – solution to change. As I said, resistance will not be futile.
> >
> > Rules changes will not happen until FCC believes they are necessary.
> The first step in moving FCC to that conclusion is to make them more and
> more aware of the impact of the present rules. With recent increased
> interest by OET and the FCC Regional Directors, that process is beginning
> to bear some fruit. It will take more.
> >
> > Ed
> >
> --
> -----------------
> David E. Crawford
> Indian River City
> Florida Libre
> -----------------
>
>
> _______________________________________________
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> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
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