Full band pulsing interference in my town

[WRKL926]

I have noticed a pulsing interference in my town (Butte, MT) that affects all GMRS channels. It does not sound like your typical Morse code keying but repeats regularly at ~1Hz. While it only covers a few blocks in the center of town, it is detectable up to SQL 5, which confuses me. Any ideas what this might be?

 

Thanks,

 

WRKL926

Butte, MT

[tweiss3]

Could be a large multitude of things, from a new traffic signal to a cable box to an invisible fence. You best bet would be to get a 70cm yagi and do some foxhunting. See if you can find the offending item, within reason. If you get close but have issues pinpointing it, you can pickup a TinySA and try to locate it by frequency and db level.

[jas]

I was just about to post about a similar problem and found your topic. Not trying to hijack the post by any mean, the problem I have seems similar but only it's only in one channel.

 

I 'm using a new Midland MXT275, which if I'm not talking I run on scan.  It's weird but there is never anyone on channel 21 (462.700), with one glaring exception. It started as best as I can describe it, a loud machine gun like tone lasting about 3-seconds. At first I thought OK, a repeater tone and left it at that. Now it has become really annoying. I can hear it everywhere in two counties, distances up to 40 miles.  And now it's very frequent, sometimes two or three bursts in a row spanning a couple three minutes. It is very loud!

 

Then I thought well I never hear anyone on that channel so it might be the radio, or some other inside the vehicle interference (that could still be the case). I tested the radio on that channel talking to my wife on her  HT and it all works perfect both ways.

 

I'm at a loss and would appreciate suggestions.

 

Best,

 

JAS

[tweiss3]

I was just about to post about a similar problem and found your topic. Not trying to hijack the post by any mean, the problem I have seems similar but only it's only in one channel.

 

I 'm using a new Midland MXT275, which if I'm not talking I run on scan. It's weird but there is never anyone on channel 21 (462.700), with one glaring exception. It started as best as I can describe it, a loud machine gun like tone lasting about 3-seconds. At first I thought OK, a repeater tone and left it at that. Now it has become really annoying. I can hear it everywhere in two counties, distances up to 40 miles. And now it's very frequent, sometimes two or three bursts in a row spanning a couple three minutes. It is very loud!

 

Then I thought well I never hear anyone on that channel so it might be the radio, or some other inside the vehicle interference (that could still be the case). I tested the radio on that channel talking to my wife on her HT and it all works perfect both ways.

 

I'm at a loss and would appreciate suggestions.

 

Best,

 

JAS

If you are close to Canada, north of line A (I happen to be 1000' north of line A) you cannot use frequencies 462.650, 467.650, 462.700 and 467.700 MHz as printed on your license. Those are channels 19 and 21, both simplex and repeaters.

 

Your interference may be from Canada's commercial/governmental license pool and may be telemetry data. You must just accept it.

[jas]

If you are close to Canada, north of line A (I happen to be 1000' north of line A) you cannot use frequencies 462.650, 467.650, 462.700 and 467.700 MHz as printed on your license. Those are channels 19 and 21, both simplex and repeaters.

 

Your interference may be from Canada's commercial/governmental license pool and may be telemetry data. You must just accept it.

 

I'm on the West Coast of Florida so that is highly unlikely!  I'm going to try to make a recording of it and figure out how to post that.

 

Best,

 

JAS

[WRAK968]

The easiest way for us to come up with a rough idea of what is happening is for someone to post a recording of the audio in question. This will allow us to hear the signal in question and we may be better able to pinpoint what the signal is.

[WRAK968]

I was just about to post about a similar problem and found your topic. Not trying to hijack the post by any mean, the problem I have seems similar but only it's only in one channel.

 

I 'm using a new Midland MXT275, which if I'm not talking I run on scan.  It's weird but there is never anyone on channel 21 (462.700), with one glaring exception. It started as best as I can describe it, a loud machine gun like tone lasting about 3-seconds. At first I thought OK, a repeater tone and left it at that. Now it has become really annoying. I can hear it everywhere in two counties, distances up to 40 miles.  And now it's very frequent, sometimes two or three bursts in a row spanning a couple three minutes. It is very loud!

 

Then I thought well I never hear anyone on that channel so it might be the radio, or some other inside the vehicle interference (that could still be the case). I tested the radio on that channel talking to my wife on her  HT and it all works perfect both ways.

 

I'm at a loss and would appreciate suggestions.

 

Best,

 

JAS

Doing a run on your license I see your in Pinellas County. Seems their FD and EMS pagers are telemetry based and are licensed between 460 and 463. Neighboring Hillsborough has several telemetry systems in 460's as well, including DMR repeaters in the 462/467 range very close to GMRS. That doesn't include all of the DMR repeaters in BOTH county's which could also be UHF band. Any of these could be the cause of your interference.

[jas]

Doing a run on your license I see your in Pinellas County. Seems their FD and EMS pagers are telemetry based and are licensed between 460 and 463. Neighboring Hillsborough has several telemetry systems in 460's as well, including DMR repeaters in the 462/467 range very close to GMRS. That doesn't include all of the DMR repeaters in BOTH county's which could also be UHF band. Any of these could be the cause of your interference.

 

Thanks! Based on what you posted I did some more research on this.  I found the exact tone on a video in YouTube, although it's much louder and clearer in person. The video is about programming Illegal FRS digital radios.  The signal is strong enough in most parts of our county to exclude an FRS radio on simplex, unless the radio is connecting to a repeater. Then again it could be any other radio that has both the capability to transmit on 462.700 and also digital. Then again, it still points to a repeater because of the distances.

 

Here is the video. I queued it to start at 14:30, a few seconds before you can hear the tone:

 

https://youtu.be/R_fYaK84VU4?t=870

 

Best,

 

JAS

[WRCZ387]

Good Afternoon

 

jas, I'm in North Clearwater/Dunedin & I have heard the signal on .700 also

 

It's often enough that I locked out .700 on my scanner,

as I usually have the repeater outputs scanning continuously

 

73

Greg