I am not sure how I could be "spectacularly incorrect" in the comment
you quoted, when I did not draw a conclusion from the data presented,
but reported only what I found...
Jim already pointed out that my initial comment:
"The problem with that approach is that most AM stations are strong
enough to override RFI, in most locations, on the AM broadcast band."
was overbroad, and I should have added in my experience. I corrected
that oversight on my part with the comment you quoted.
You drew the conclusion from that corrected comment, that I am saying it
won't happen to others, and that I am saying it is not an issue for the
broadcast industry... I used to be assistant CE for a local TV station,
(prior to retirement after 40 years in the BC industry), so I was in the
Broadcast industry... Not AM, but TV, and I was exposed to AM CEs all
the time at SBE meetings, in 40 years not one of them brought up a
single RFI incident... Not to say there were none, just not enough to
prompt even a passing discussion...
In the primary coverage area for one of our 50KW AM locals, I have sat
in the driveway, or at the curb, less than 50 feet from the lights
causing major RFI, and heard nothing while tuned to an the 50KW
station-- in all cases, save one...
I desperately hope the broadcasters get in the mix more than they are
already. One of the first things I do, is to check the AM radio,
looking for a local station that I can contact to involve them... I
just have not had that happen more than once in the last 15 or so
events... That is what I am saying.
I am not saying that it is not a problem for broadcasters, just that for
me, it has not been a venue I can use to help solve the issue because it
is not happening for me. It will not happen to everyone either.
I hope this clears up my position in this...
73, and thanks,
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources
On 12/16/19 3:48 AM, Rob Atkinson wrote:
<Respectfully, in every case here but one, (and I have been involved
in maybe 10 to 15 in the past three years), the RFI from grow ops were
unheard on the AM band with a local station tuned in, and while in
front of the offending grow op. I am sure that in some cases it is
hearable on an AM channel, but so far here, (and I have expressly,
checked at each location), I have had very little luck with this. It
is one of the first things I check for, so I can involve the CE of the
AM station being affected...>
Dave you could not be more spectacularly incorrect. You're mistake is
generalizing based on your own limited experience. The broadcast
industry is extremely concerned about the noise floor. Around here,
even 50 KW AMs are affected, and you don't have to be outside their
primary service contour to tell. All you need do is google SBE AM
noise floor. This is probably the single biggest issue in medium
wave AM today.
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