MOH P-COMM interference

[mrweather]

Anyone in the Streetsville area of Mississauga notice an open carrier on 150.100 the past couple of days? I don't think it's a local RFI issue because I can also hear it while driving around the area.

 

[derevs]

Anyone in the Streetsville area of Mississauga notice an open carrier on 150.100 the past couple of days? I don't think it's a local RFI issue because I can also hear it while driving around the area.

I have locked it yesterday and today.
Because of the buzzing sound it appears to be some sort of jammer.
Anyone else around the province noticing this buzz?

 

[randyf]

All good in the middle east.

 

[mciupa]

All is well in NW Toronto.

Squelch set at 2 on my 536. It flies by that frequency. I'll keep it on Hold for now.

Spoke too soon. Sitting on the frequency and heard six key clicks.

 

[ATCTech]

That sounds very much like a transmitter stuck on connected to a partially grounded landline or partially failed power supply in the radio itself. "Been there, done that" with ATC stuff many times. It's all but a needle width from S9 out here. Loud and, well, clear, if you like hum.

 

[mrweather]

Thanks all for the feedback. Since P-Comm is simplex I figured it was something nearby (a few km at most). Makes me wonder whose transmitter is stuck? It's definite a fixed location (or maybe a parked ambulance somewhere) as the signal strength hasn't changed.

 

[ATCTech]

Unless the ambulance is 2km from me, it's a fixed-base transmitting site. There are loads of sites, but two jump out at me based on signal strength Fonthill, and 262 Britannia Road East in Mississauga, coincidentally or otherwise the location of Fleetnet site 09..... take it from there of any further speculation.

 

[gary123]

Might also be a hospital transmitter. There is still some old obsolete hardware still gathering dust at several facilities.

 

[ATCTech]

It's cleared now.

 

[mrweather]

It's cleared now.

It did the same thing last night but came back this morning.

Credit Valley hospital isn't far from me. Could be something there.

 

[ChuckWillis55]

I have locked it yesterday and today.
Because of the buzzing sound it appears to be some sort of jammer.
Anyone else around the province noticing this buzz?

Not just happening in the GTA area. It seems to be affecting other areas as well. The London CACC said it sounds like an open mic. It affected communications with the London air ambulance this morning. They could not communicate with ground ambulances on scene at an incident outside of Waterloo. Because they could not communicate directly, they had to return to base. I heard them talking to Med-Com on the helicopter channel advising of the situation - no P-Com, no sat phone.

 

[jasoyeom]

I'm also hearing the hum on 150.100 here in Norfolk. A little weak but it's there for sure.

 

[jasoyeom]

The hum is back with at pl code of 179.9 here in Norfolk county.

 

[ChuckWillis55]

Just checked and I hear it too.

 

[ATCTech]

PL code of 179.9 Hz sounds like your radio is interpreting 60 Hz hum at a harmonic of 180 Hz? Not an unusual event. That noise from what I recall sounded an awful lot like a bad cable pair or failed power supply rectifier somewhere in the system causing 60 Hz electrical noise to modulate the transmitter(s).

 

[gary123]

A poor audio coupling or ground can cause the hum as well.

Maybe we should DF the interference just for the fun of it. It's not too hard to do. While mobile, measure the signal strength in your area. When you have a full scale signal remove the antenna or change from a VHF to a shorter whip to reduce the signal levels. When that gets full scale remove the antenna open the squelch and hunt again. Also the signal may be coming from an EMS station or a hospital, so start concentrating hunting in those immediate areas.

Drive safely, you do not want to get nailed for distracted driving or worse, smash up your vehicle.