Hi Frank and gang,
I might be able to help provide some additional insight/direction. This is
not necessarily a case of having to show harmful interference, as the AM
Broadcasters are held to some very stringent spurious emission limits and
the stations actually go through a periodic inspection to show compliance.
If the IMD is being generated within their hardware and they exceed the
emission limits as stated in section 73 of the FCC rules then the station
must address the problem (no need to prove harmful interference to anyone
for it to be a problem that needs to be fixed). If I were in the area I
would try and confirm the IMD is originating from the property of the
transmitter site, and then make an attempt to measure the spurious emission
signal strength relative to the carrier frequency signal strength (an
approximation is fine) to show that the spurious emission likely exceeds
the allowable limits. After achieving this I would then contact the
station general manager to explain the situation including the fact that
ham radio operators over a pretty large geographic area are hearing their
out of band spurious emissions and then have him put you in direct contact
with the chief engineer of the station to look into the problem (this
sometimes requires a lot of digging before you are able to make contact
with the right people).
I have dealt with a few AM broadcast station as well as TV station problems
and the biggest hurdle is getting in contact with the chief engineer, but
after getting in contact with the chief engineer the problem gets addressed
but maybe not at the speed of light as many AM broadcast stations are in
dire financial times and they often don't even have a full time chief
engineer and the chief engineer most likely will not have the skill set to
fix the problem and he will likely need to call in a RF consultant . I
would certainly avoid getting the FCC involved as a first step unless
working directly with the station general manager and chief engineer fail.
This normally does not need to be a confrontational situation as the chief
engineer wants to make sure his station is in compliance. In a recent AM
broadcast station case I was involved with both the part time chief
engineer and RF consultant were hams which made life easy.
Just my opinion based on some past experience.
Don (wd8dsb)
On Fri, Jan 6, 2023 at 10:07 PM Frank W3LPL <donovanf@starpower.net> wrote:
> Hello AJ,
>
> Topbanders have done an excellent job of precisely identifying the source
> of the 1940 kHz intermod.
>
> I don't think its helpful for those of who are not being harmed to lodge
> a complaint with the FCC. Its the responsibility of those being
> harmed t file a complaint. Those being interfered with also have a knob
> on their radios that allow them to avoid interference.
>
> American amateurs suffering harm can file a complaint to the FCC.
>
> Canadian amateurs can lodge a complaint to their regulatory authority,
> that authority can then file a complaint to the U.S. government. It's
> a routine process used often.
>
> 73
> Frank
> W3LPL
>
>
> From: "A J" <iamfromcanadaalso@gmail.com>
> To: "Frank W3LPL" <donovanf@starpower.net>
> Sent: Saturday, January 7, 2023 1:39:11 AM
> Subject: Re: 1940 kHz intruder WWRU WKMD
>
>
>
> Hi Frank
>
> How do we define harmful interference?
>
>
>
>
> I know some of the guy's that talk on 1940 and at times it makes it
> impossible for them to talk.
>
> One of the gents is located near Barrie Ontario (480 miles) and at times
> he can not even hear others he is talking to. Others near Buffalo others in
> north west Pennsylvania.
>
> About 380 miles to my location. I had a friend near North Bay Ontario
> listen when I was trying to figure out where it was coming from or what
> stations it was he is 500 miles away and it is heard there.
>
>
> I hear it before ~1hr sundown and hear it about 45 minutes after sun rise.
>
>
> Other times I have heard it mid morning.( signal level from S3 to S9+10
> with ~12 db attn)
>
>
> Is it possible it is re-radiating from some other structure?
>
>
>
>
> Cheers AJ___ VE3HJ
>
>
> On 1/6/23 19:40, Frank W3LPL wrote:
>
>
>
> Hi AJ
>
> In my opinion, the next step is to determine if this intruder is causing
> harmful interference,
>
> Several of us can hear it weakly and intermittently hundreds of miles
> away,
> but so far no one has claimed that its harmful.
>
> 73
> Frank
> W3LPL
>
>
> From: "A J" [ mailto:iamfromcanadaalso@gmail.com | <
> iamfromcanadaalso@gmail.com> ]
> To: "Frank W3LPL" [ mailto:donovanf@starpower.net | <
> donovanf@starpower.net> ]
> Sent: Saturday, January 7, 2023 12:27:47 AM
> Subject: Re: Topband: Spur as it reappeared
>
>
>
> Hi Frank
>
> So what is the next step?
>
> What do we do?
>
>
>
>
> AJ___ VE3HJ
> On 1/6/23 18:44, Frank W3LPL wrote:
>
> BQ_BEGIN
>
> Hi George,
>
> Faulty day/night switches may well be the cause! You may have seen
> in my previous email that both stations switch patterns from day to night.
>
> This is the first time I've ever hears of two AM stations with two
> antenna arrays sharing the same small site
>
> 73
> Frank
> W3LPL
>
>
> ----- Original Message -----
> From: "George Hirst" [ mailto:geohirst@yahoo.com | <geohirst@yahoo.com> ]
> To: "Rick Stealey" [ mailto:rickstealey@gmail.com | <rickstealey@gmail.com>
> ] Cc: [ mailto:wd8dsb@aol.com | wd8dsb@aol.com ] , "donovanf" [ mailto:
> donovanf@starpower.net | <donovanf@starpower.net> ] Sent: Friday, January
> 6, 2023 11:39:10 PM
> Subject: Re: Spur as it reappeared
>
> I am “talking through my hat” here. The fact that it seems to suddenly get
> much stronger right about your (New Jersey) sunset make me wonder if it is
> related to the AM broadcast station(s) changing their antenna pattern(s).
> (I haven’t done the research to know if these stations are ones that are
> required by the FCC to change their patterns at night to “protect” more
> senior stations who share the sane frequency.) Perhaps there is some
> corrosion on the RF switches employed in that function that introduces
> nonlinearities. Those nonlinearities result in mixing products (ie. 1940
> kHz) which are then radiated. ????
>
> George - WF4U
>
> BQ_BEGIN
>
> On Jan 6, 2023, at 4:14 PM, Rick Stealey [ mailto:rickstealey@gmail.com |
> <rickstealey@gmail.com> ] wrote:
>
>
> Note the waterfall. The timestamp on the right is accurate. The
> horizontal line is a lightning burst. But notice the ugly signal that came
> up on 1940 before the carrier. Anyone have any idea what is happening
> there?
>
> <image.png>
>
>
>
> _________________
> Searchable Archives: [ http://www.contesting.com/_topband |
> http://www.contesting.com/_topband ] - Topband Reflector
>
> BQ_END
>
> --
> Knowledge is Power and Power is Knowledge.___AJ___1967
> Tell me and I will
> forget. Teach me and I may learn. Involve me and I shall understand.
> ___AJ___
>
>
> BQ_END
>
> --
> Knowledge is Power and Power is Knowledge.___AJ___1967
> Tell me and I will
> forget. Teach me and I may learn. Involve me and I shall understand.
> ___AJ___
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
_________________
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