NY State Police input frequency coming over Peterborough Fire repeater

[Jradioptbo]

The Tropo is so strong tonight.
There are comms from State Police hitting the input frequency to the Peterborough city fire repeater system, causing interference relaying it the output 154.250. What are the chances of having the same PL tone?
I believe Peterborough fire is aware of this.
I can hear cars being pulled over, and us highway references.

KUZ980 NY State Police
155.595 PL tone 146.2
Which happens to be the input into Peterborough Fire.

 

[Andy_SDS100]

I wonder what they will do about that?

 

[nd5y]

I wonder what they will do about that?

We have the same problem here. Not much they can do except quit using VHF and move to UHF or 700/800 MHz which have band plans where there will never be repeater outputs on your input frequency anywhere in the US or Canada.

They can change PL tones but that will only hide or shift the problem because are lots of other repeaters on 155.595 (in the US anyway) and if there is another good tropo opening they will get interference from somebody else.

Occasionally around here during band openings you can hear two VHF repeaters with the same PL and input/output frequencies reversed that lock up with audio feedback.

 

[DS506]

Explains what I was hearing last night. I don't recall the VHF freq. scanner stopped on a small PD with all noise, yet occasionally I could hear them over the noise. It wasn't just me, one officer told the other two cars and dispatch to move to the county (frequency).
I now think the noise was a more distant trunked control channel.

 

[sirsmiley]

Why are State Police using analog for police in this day in age?

 

[gary123]

Tech time:

At work one tech said going DMR will eliminate this type of interference. He's wrong. What will happen is the interfering signal will not be repeated due to issues like CC. BUT even if you hit the jackpot and match CC the ISW/OSW timing will prevent you/them from accessing each others systems.
The interfering signal is still there and if strong enough can capture out the local signal or cause such a high BER that the system(s) may be totally un-useable. The way the hardware is configured the user may not even know what's happening as there is no external indication of the interference. Remember the RX audio is muted until a decode able signal is received.

 

[sirsmiley]

Tech time:

At work one tech said going DMR will eliminate this type of interference. He's wrong. What will happen is the interfering signal will not be repeated due to issues like CC. BUT even if you hit the jackpot and match CC the ISW/OSW timing will prevent you/them from accessing each others systems.
The interfering signal is still there and if strong enough can capture out the local signal or cause such a high BER that the system(s) may be totally un-useable. The way the hardware is configured the user may not even know what's happening as there is no external indication of the interference. Remember the RX audio is muted until a decode able signal is received.

Still NYS needs to go to P25 or something in this day in age for privacy and encryption and frequency efficiency. Analog doesn't do very narrow. Only narrow and wide

 

[gary123]

LOL I'm sure many would disagree with the general concept if if they are encrypted we should be too. I am actually surprised that two adjacent users would be assigned the same freq. This type of thing is supposed to be co-ordinated. Services like State Police in the US and even Fire seem to have FCC licencing that allows for decent power (50-100W) where as Canada is limited to 30W ERP type of thing. Its not surprising the US user comes blasting in when conditions are favorable.

 

[FFPM571]

It's Skip or Ionosphere ducting the conditions are just right for it to happen. Its temporary. It used to happen occasionally on our fire repeater. A department in central Indiana had the same output and PL as the input of our fire repeater outside Chicago.

One morning they had a working fire that tied the repeater up for 3 hours The dispatcher was finally able to disable the receiver site that was getting most of the traffic and it was still pretty busy

Why are State Police using analog for police in this day in age?

Because it works.

 

[nd5y]

I am actually surprised that two adjacent users would be assigned the same freq. This type of thing is supposed to be co-ordinated. Services like State Police in the US and even Fire seem to have FCC licencing that allows for decent power (50-100W) where as Canada is limited to 30W ERP type of thing. Its not surprising the US user comes blasting in when conditions are favorable.

In the US frequency coordination is required for almost all PLMR licenses. Co-channel base stations or repeaters (both input and output) within 70 miles usually aren't allowed, but the distance can depend on antenna HAAT. It's impossible for frequency coordination to take into account tropo openings. There are too many licensees and not enough spectrum.

If there is a good tropo opening transmit power makes little difference. I have worked stations over 150 miles away with 25 watts or less. Sometimes while mobile. One time I had a 2 watt hand held and worked a repeater 350 miles away.

 

[Jradioptbo]

What's even more interesting is Rochester, NY Fire channel 2 is 154.250, Different PL tones. If you draw a straight line from Peterborough, Ontario to Rochester, NY, It's not far. Some of the towers in this area are high up. Including those near Oak Ridges elevation to the south.

You would figure FCC and ISED Canada would have better coordination, but it is up to the license user to complain to their radio service provider. Because as a license user, there is no guarantee of a protected contour, even if ISED has it that way.

Anomalies such as tropo. Engineering software is good to provide contour to geography data, on HAAT and TPO and so on, when putting up towers and repeaters. There's always that area of the equation the software cannot account for accurately.

But as more agencies switch to digital and change bands, it will help somewhat, but interference, is not 100 percent full proof

 

[ecps92]

Because it works ?

Why are State Police using analog for police in this day in age?

 

[IdleMonitor]

I routinely throughout the summer pick up an emergency service I believe from Elmira, NY on the output of a repeater (163.800 PL 110.9) in Greater Madawaska Twp that has the Renfrew County fire dispatch on it. I hear a fair amount of activity from there on this repeater. It comes an goes but is still frequent enough.

 

[PriorMike]

Still NYS needs to go to P25 or something in this day in age for privacy and encryption and frequency efficiency. Analog doesn't do very narrow. Only narrow and wide

They don't "need" to do anything.

 

[mrweather]

Used to happen on occasion when OPP were on low-band and there'd be interference from Missouri state police.

 

[chrismol1]

Still NYS needs to go to P25 or something in this day in age for privacy and encryption and frequency efficiency. Analog doesn't do very narrow. Only narrow and wide

LOL get outta here with that. Just because your locked down, doesn't mean us over the river need to be too. I know, crabs in a bucket. The NYSP does just fine with their current system and has current upgraded radios. Many do operate on P25 on the counties systems