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Unstable / Off Frequency on 1040

A

audioguy

Heard for several days now... an off frequency station on 1040 riding on top of WHO. The carrier drifts slowly up and down about 200 Hz. It was most evident between about 6 a.m. and 7 a.m. EDT in SW MI. Anyone else hear this or have an idea where it is coming from?

Still haven't caught the guy on 1290 and it's still off frequency as well.
 
Its most likely from Mexico. Here in South Texas, it is almost impossible to do any decent amateur, low cost DXing due to all of the Mexican AMers blasting northward. When I discovered DXing in 1974, I could regularly receive WLS, WSM, WSB and many others. But recently, forget it. Maybe its because our stations use less power and the Mexicans maintain full power?
 
Been hearing it for a while now, however, I hear the het during the sunset hours. Haven't checked lately, but it wasn't there during the night hours. This leads me to think it may be a daytimer.

There seems to be a growing number of frequencies with hets. I just assumed they were Cuban or maybe Mexican stations.
 
I hear the FCC complained, but the Mexicans responded by demanding that we give them all amnesty! :D
 
This morning I was able to catch the unstable station as it came on the air right at 6 a.m. EDT. So apparently it is either a daytimer or a station that increases power/changes pattern at that time.

Can anyone confirm if a 6 a.m. switch means that the station would be in the Eastern time zone? That would be helpful to know.

Apparently this station must be operating off-frequency during daylight hours, would make them a sitting duck for a frequency check.
 
audioguy said:
This morning I was able to catch the unstable station as it came on the air right at 6 a.m. EDT. So apparently it is either a daytimer or a station that increases power/changes pattern at that time.

Can anyone confirm if a 6 a.m. switch means that the station would be in the Eastern time zone? That would be helpful to know.

Apparently this station must be operating off-frequency during daylight hours, would make them a sitting duck for a frequency check.
Click to expand...

AM broadcast stations in the US are required to be within ±20Hz of their assigned frequency, which is subaudible. This is pretty odd that their carrier is off so much that they are heterodyning other stations on 1040. Modern broadcast transmitters built in the last 30+ years should have an indicator/alarm if the frequency drifts near or beyond the ±20Hz. And there is no excuse for a remote control/monitoring operation: my understanding is that the FCC requires Full Control of frequency, power, modulation, etc. remotely, and if a station cannot control these parameters they must be able to shut the transmitter down immediately if the problem cannot be corrected quickly!

It would be necessary to find out the schedule for the station in question: http://www.fcc.gov/mb/audio/bickel/srsstime.html For example, on 1040, WYSL Avon-Rochester, NY, has a sunrise time of 4:45 a.m. ET in May, but 4:30 a.m. ET in June. So it's not WYSL. They have an excellent operation over there at WYSL, not gonna happen with them! Stations could also sign on with daytime power later than sunrise according to the FCC SRSS table for a specific station, so there are several variables at play here.

One can look up a specific AM station here: http://www.fcc.gov/mb/audio/amq.html and there is a link "Approximate Sunrise & Sunset Times" on the result page for that station for its sunrise/sunset times. radio-locator.com or http://www.fcc.gov/mb/audio/amq.html would be a couple of good places to start to give a list of all the stations on one specific frequency.
 
Stormy, thanks for the tips on how to find the sunrise/sunset times. I did a search on 1040 looking only for stations with W calls, and that shortened up the list considerably.

Based on received signal strength, I'd say the interfering station is either east or west of my location. I'm going to say east, due to the time the interference starts (6 a.m.). Looking at the list of stations that came up, I'm guessing that WJTB North Ridgeville OH is a good possibility. They have a local sunrise of 6 a.m. for May (EDT). They're also a daytimer (with critical hours). I've got to check out a few others, but I think I will start with them.

Both the 1040 and 1290 hets are way off frequency. Far beyond 20 Hz. I'm estimating 200-400 Hz in the case of the 1040 station.
 
I just identified a second possibility, WZSK, Everett, PA. Both stations have 6 a.m. local sunrise times. Anyone living within daytime range of either WJTB or WZSK please let me know if you can determine whether either of these stations is operating off frequency. Thanks!
 
kilokat7 said:
I think I determined this was WJTB Ohio back in April after picking up some audio. See the middle of this thread:
http://boards.radio-info.com/smf/index.php?topic=165736.0
Click to expand...

If someone is absolutely sure that it is still WJTB after a month of this still happening, please let them know!

Someone who is actually getting the interference do call the station (216-327-1844) and tell them they are off frequency. It's best that someone who is actually experiencing the interference describe it to them...I'm sure they would appreciate knowing that fact so they can correct it, and possibly avoid an FCC fine.
 
Here's exactly how the presumed WJTB carrier appeared as recorded on April 2nd, 2010 at 10am EST:

http://amdxer.com/misc/1040khz_02AP10_1359UTC.jpg

This is way outside the ±20Hz tolerance, and it's visually clear how unstable the carrier is. Those who have heard this drifter can attest to this just by listening to it rise and fall over a short period of time. It's interesting to be able to "see" it using the waterfall display on the SDR.
 
Beside annoying listeners to others stations on the same frequency, they are hurting their own signal, as their audio will beat against
the het for the stations who ARE on freq, reducing their own effective coveage area.
 
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