Data interference on OPC Common 142.770

[phyberoptics]

Anyone else noticed the data interference on 142.770? It sounds like a control channel from an adjacent frequency. I've heard it in Mississauga, and Orangeville (not sure if that's from the same transmitter site or where that even is). Heard it on several radios too, so I don't think I'm halucitooting.

 

[highstupid]

I as well have heard this but I hate to lock that channel out and miss something


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[mciupa]

Anyone else noticed the data interference on 142.770? It sounds like a control channel from an adjacent frequency. I've heard it in Mississauga, and Orangeville (not sure if that's from the same transmitter site or where that even is). Heard it on several radios too, so I don't think I'm halucitooting.

It's been a problem since I wrote this:

08-14-2016, 12:46 PM

If you give 142.770 a listen, you will notice a persistent "noise" being transmitted for seconds at a time, then it breaks and shortly resumes again.

Kind of annoying when you are trying to scan.

 

[exkalibur]

It's coming from the TPS tower at Yonge and the 401. That's what you get for having a CSQ repeater in Toronto...

 

[motomeso]

It sounds like local intermod coming from the site. If they had the repeat disabled like they're suppose to it wouldn't be an issue.

On a side note, you can hear that damn tower just about everywhere.

 

[gary123]

I have heard it in Kitchener and Goderich and London occasionally. Maybe someone will make a call to Metro Telecom .

can anyone identify the source of the data on the repeater input? ie 138.755 or whatever?

 

[Jammin_Jay]

i believe The comm centers can activate the repeater, by switching it off or on, and also in sequence with others depending on the radio traffic from that area that warrants it from which ever agency opp and local police that are in that tower location. I dont believe they are picking up this noise in the comm center or they would have acted upon this asap. You can check the input, but not sure thats it, could be leakage from intermod. Who knows. The amount of Intermod in Toronto terrible it would require 15 x filtering to supress 10 percent of it, lol. I think the input frequency is standard 4.020 split negative, which would make it 138.750

 

[gary123]

Thats the issue is it intermod? or is it an adjacent freq. The fact the repeater is repeating it is fixable but obviously someone does not want to or cannot disable the repeat function at that site. Identifying the actual signal that is being picked up by the input will go a long way to eliminating this headache.

 

[DaveH]

If the problem is at the site e.g. intermod, we could listen to the input 138.750 from a distance and might not hear it.

Repeater offset is -4.02MHz in this case, but there are lots of exceptions in Fleetnet.

I recall several years ago, military aircraft on the US side operating in the 138MHz range were interfering with a Canadian ground repeater; forgot the frequencies and other details, would need to dig back into my notes. Probably not the cause of the OPC repeater problems here but worth keeping in mind.

Dave

Also, knowing any other transmitters at that site could provide a clue.

 

[exkalibur]

Well the interference sounds very similar to an NXDN signal, so that might be a clue.

 

[motomeso]

If a tree falls in the forest and nobody heard it, did it really fall?

Thats the issue is it intermod? or is it an adjacent freq. The fact the repeater is repeating it is fixable but obviously someone does not want to or cannot disable the repeat function at that site. Identifying the actual signal that is being picked up by the input will go a long way to eliminating this headache.