The other day I saw something quite ironic at our local post office.
There on the door, a bright red sign with white lettering was posted.
It stated that cell phones are banned inside the post office lobby
because they interfere with the point-of-sale terminals the clerks
use. At least someone besides the hams is getting blamed in this
rare case. Various electronics manufacturers have been very
successful in lobbying and getting themselves exempted from any
meaningful RFI immunity requirements. The resulting lax
environment has come nearly full circle with this proposed new
data service. If this mode is permitted, it strongly reverses the
effort made to get various digital equipment reasonably well
suppressed as RFI emitters. The proposed service is a joke, in
that regard. Manufacturers have spent millions on RFI reduction
mandated by the US FCC, over the years, for their digital gear.
Power line modems pretty much turn this on its head. It may not
affect the majority, but certain hams and others will probably
experience significant interference on the HF bands. This proposed
gear is probably especially a dog on top band. No doubt, the bulk
of the energy would be towards the lower end of the spectrum,
where the various insulating materials distributed throughout the
signal paths are the least lossy. The emissions will probably be
similarly oppressive like incandescent light dimmers using
triacs. Goodbye 160 meters, if you happen to end up with a
neighbor with one of these! I hope they stop this thing before it
gets too entrenched. It will probably take some litigation. I have
my doubts whether the hams could successfully fight it if the FCC
does not care to. We have certainly had little or no success
getting manufacturers of susceptible equipment to act responsibly
by installing shielding and filtering in previous efforts. As low band
DXing involves weak signal work in an already noisy slice of
spectrum, this is certainly not good news. Let us hope it dies
the same ignoble death as LEOSATs. 73, David K3KY
P.S. de W4ZV...excerpts of a private message from DF2PY:
"I just want to bring some good news. The powerline technique is almost
abandoned now. The Mannheim experiment is a thing of the past. Even big
companies like Siemens are out of it now and gave up on it officially.
A company from Israel bought the rights but things are quiet since.
Bandwidth and speed are not matching the expectations."
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