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WBAP 820 board op ASLEEP again? Can hear 990 'splatter' easier that way anyway ...

J

_Jim

Guest
Back half of 2nd hour of nationally syndicated program
had LOW AUDIO coming out of first commercial break.

And just for the record, when this happens, you can
REALLY hear the 'crap' that is radiated by 990 KFCD
that centers on/about 836 KHz that 'FMs' low enough
in frequency to be heard under WBAP's audio when 990's
program audio picks up.

There is also some crap coming out of 990 that appears
about the 1140 (+150 KHz above 990) area, although I
have not documented that aspect as heavily with RF
spectroscopy (spectrum analyzer photographs) as I have
done with the errant RF energy down in the 836 KHz area.

Surmising, it appears that there is some spurious or
'switching' frequency component 'run amuck' in the 990
transmitter, and it affects/is audible under the follow-
ing stations down into at least into central Plano east
of US-75:

1) 820/WBAP,
2) 850/Super Tejano and
3) also as high as 1190 (Mighty)
 
RF Spectroscopy of 990 'spurious' signal on 836 LHz

First picture, showing garbage emanating from 990 when
program audio on 990 is absent (quiet passage with no
audio):

Mvc-038f_cp.jpg


Verifying that this garbage (the blip in the center of the
screen) is coincident with the on-air program audio coming
from 990 is a no-brainer. It is quite easy to make the
connection between this signal and 990's audio while watching
the spectrum analyzer OR listening with a narrow band receiver
to this 'crap' AND a radio tuned to 990.



<hr noshade>



Here the garbage is absent, although its not really - it is
at this point that the 'garbage' is FMing (spread) down
to 820/WBAP's frequency and up to 850's as well. The effect
is a 'scratch' that can be heard during quiet passages on
820, 850 OR 1190.

Mvc-040f_cp.jpg
 
Re: 990 interference

I don't notice it on my mono AM receivers, but on my C-QUAM AM Stereo one, I do hear a program beneath WBAP's. Is that what this is? VERY irritating. What's 990 sending out that makes this happen? I know HD was the last thing to ever cross Schum's mind (right down there with other acronyms like IRS, W-2, W-4, 1099, FICA, FET, etc) so it can't be that, right?

Does someone need to call the FCC and report this?

> Back half of 2nd hour of nationally syndicated program
> had LOW AUDIO coming out of first commercial break.
>
> And just for the record, when this happens, you can
> REALLY hear the 'crap' that is radiated by 990 KFCD
> that centers on/about 836 KHz that 'FMs' low enough
> in frequency to be heard under WBAP's audio when 990's
> program audio picks up.
>
> There is also some crap coming out of 990 that appears
> about the 1140 (+150 KHz above 990) area, although I
> have not documented that aspect as heavily with RF
> spectroscopy (spectrum analyzer photographs) as I have
> done with the errant RF energy down in the 836 KHz area.
>
> Surmising, it appears that there is some spurious or
> 'switching' frequency component 'run amuck' in the 990
> transmitter, and it affects/is audible under the follow-
> ing stations down into at least into central Plano east
> of US-75:
>
> 1) 820/WBAP,
> 2) 850/Super Tejano and
> 3) also as high as 1190 (Mighty)
>
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

A veteran chief engineer in this market has told me that 990 has been operating illegally off & on over the past few months to obtain stronger signal measurements to show to the eventual owner.
 
Re: 990 interference

> I don't notice it on my mono AM receivers, but on my C-QUAM
> AM Stereo one, I do hear a program beneath WBAP's. Is that
> what this is? VERY irritating. What's 990 sending out that

You may be hearing it, depending on the program material
appearing on 990 KFCD.

Take a second receiver tuned to 990 and see if there is any
'match' to what you're hearing. It took me a few weeks to
finally put two and two together and isolate source of this
interference. In the process I cleared 770 KAAM and Super-Tejano
850 or any other station except 990. Of this fact I am absolutely
with 100% certainty pointing the finger at 990 as the source
of this interference (I don't do this lightly; the icing on
the cake was the coincidence I witnessed while observing the
spectrum analyzer and listening to the interference on 836 KHz
and noting 100% coincidence with 990 program audio. Noteworthy
as well is the fact that this interference is not receive-site
specific, like noticable at the office only or at home only).


> what this is? VERY irritating. What's 990 sending out that
> makes this happen? I know HD was the last thing to ever

It appears they have spurious 'components' approximately +-150 KHz
from their assigned frequency of 990 KHz coming out of the transmitter,
perhaps as a result of a fault of a PWM (pulse width modulator)
transmitter that has some sort of problem with the Pulse Width
Modulator low pass filter circuitry.


> makes this happen? I know HD was the last thing to ever
> cross Schum's mind (right down there with other acronyms
> like IRS, W-2, W-4, 1099, FICA, FET, etc) so it can't be
> that, right?

Right.

It is is some sort of technical problem and not a result of
any attempt to do stereo or AM IBOC HD or any other format.


>
> Does someone need to call the FCC and report this?


It's been going on now for at least a month that I will
attest to. I didn't until last week have a chance to
muster some test real gear and a variety of receiving
equipment to finally converge on an answer as to who
was causing this inference, so now I suppose I could
make an informed complaint about it as well.

Regards, _Jim



>
> > Back half of 2nd hour of nationally syndicated program
> > had LOW AUDIO coming out of first commercial break.
> >
> > And just for the record, when this happens, you can
> > REALLY hear the 'crap' that is radiated by 990 KFCD
> > that centers on/about 836 KHz that 'FMs' low enough
> > in frequency to be heard under WBAP's audio when 990's
> > program audio picks up.
> >
> > There is also some crap coming out of 990 that appears
> > about the 1140 (+150 KHz above 990) area, although I
> > have not documented that aspect as heavily with RF
> > spectroscopy (spectrum analyzer photographs) as I have
> > done with the errant RF energy down in the 836 KHz area.
>
> >
> > Surmising, it appears that there is some spurious or
> > 'switching' frequency component 'run amuck' in the 990
> > transmitter, and it affects/is audible under the follow-
> > ing stations down into at least into central Plano east
> > of US-75:
> >
> > 1) 820/WBAP,
> > 2) 850/Super Tejano and
> > 3) also as high as 1190 (Mighty)
> >
>
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

> A veteran chief engineer in this market has told me that 990
> has been operating illegally off & on over the past few
> months to obtain stronger signal measurements to show to the
> eventual owner.
>

That would roughly coincide with time period I've been
hearing the 'splatter' on WBAP, as described earlier in
this thread!

I think I noticed this 'stuff' appearing a couple of months
back, but you know how these things go - if you don't write
it down then, with so much else going on some things just
slip through the cracks.

Regards, _Jim
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

> A veteran chief engineer in this market has told me ...


Hmm... maybe we should get an FIM 41 out and run the monitor points for that station. I'm sure if the potential buyers aren't interested in that data, the FCC would be!!!<P ID="signature">______________
vide0 killed the radi0 star</P>
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

> > A veteran chief engineer in this market has told me ...
>
>
> Hmm... maybe we should get an FIM 41 out and run the monitor
> points for that station. I'm sure if the potential buyers
> aren't interested in that data, the FCC would be!!!
>
AHHHHH Is it time for another heel clicking modulated adventure of the Radio Avenger???? Edward?
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

> Hmm... maybe we should get an FIM 41 out and run the monitor
> points for that station. I'm sure if the potential buyers
> aren't interested in that data, the FCC would be!!!


Well after writing the above post, I got a phone call. From what I understand, since they quit paying everyone (including the engineering staff), nobody has even so much as BEEN to the transmitter to run monitor points or check on it. Goodness knows what it's doing. Supposedly the weeds are so tall one cannot even make it to the transmitter building from the road, and the doghouses are in all forms of disarray. The phasing cabinets are older than I am, and don't work worth a darn.

Also, they evidentially do not have a way to remotely control the transmitter from the control room. (Read: THIS IS ILLIGAL) I wonder how many OTHER laws they're breaking!?!?! I hope whoever buys this POS knows full well what they're getting themeselves into. Or they should be ready to bulldoze and start over!<P ID="signature">______________
vide0 killed the radi0 star</P>
 
Re: 990 interference

> > Does someone need to call the FCC and report this?
>
>
> It's been going on now for at least a month that I will
> attest to. I didn't until last week have a chance to
> muster some test real gear and a variety of receiving
> equipment to finally converge on an answer as to who
> was causing this inference, so now I suppose I could
> make an informed complaint about it as well.
>
> Regards, _Jim

Ya gonna lodge a complaint againsst all the dead air you timed with a stopwatch too?
 
Re: RF Spectroscopy of 990 'spurious' signal on 836 LHz

> I think I noticed this 'stuff' appearing a couple of months
> back, but you know how these things go - if you don't write
> it down then, with so much else going on some things just
> slip through the cracks.
>
> Regards, _Jim

Funny, considering you're so good at timing dead air on a radio station, and you remember it, all to the exact second, so well...
 
All seemed quiet today; problem most likely solved; Thanx to all involved

Initial indications are that the 'scratch' under WBAP/820 is
gone, and 1190 seemed clear as well, but testing tomorrow
during daylight hours will indicate for sure.

Again, thanks to all involved. I'm just glad that annoying
scratch is gone.

Regards, _Jim
 
Re: 990 interference

> Ya gonna lodge a complaint againsst all the dead air you
> timed with a stopwatch too?
>
ummm... methinks you have issues. Take a chill pill!!<P ID="signature">______________
vide0 killed the radi0 star</P>
 
Re: 990 interference

> > Ya gonna lodge a complaint againsst all the dead air you
> > timed with a stopwatch too?
> >
> ummm... methinks you have issues. Take a chill pill!!

No, it ain't issues. This goes back to _Jim's post where he timed dead air on a station and then reported it here. Some of us enjoy giving him a hard time about that. :)
 
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