nd5y
Member
The city were I live has a Harris P25 simulcast system.
I noticed sometimes while running Unitrunker the "signal strength" bar graph will drop out. I thought this was strange because the scanner/Unitrunker location is less than a mile from one of the sites and it is strong enough to overpower the other simulcast sites so it's not a distortion issue.
I started listening to the control channel audio and found that every once in a while the audio (cc data stream) stops for up to a second or so and there is either a dead carrier or what sounds like a ~1200 Hz square wave type tone. I tried to record this but of course it won't happen when I want it to. The attached file has some very short dropouts and tone but it can last up to about 2 seconds.
The system has four transmit sites and another four or so receive sites. Site backhaul is by microwave. I don't know if there is any wire or fiber to backup the microwave paths.
The CC audio dropouts/tone appears to occur at random intervals and durations so I don't think it is some type of simulcast alignment function. I can't tell if this is happening on all four transmit sites at the same time. Could the CC audio dropping out be a result of the controller failing or losing contact with sites? Has anybody else seen anything like this?
I noticed sometimes while running Unitrunker the "signal strength" bar graph will drop out. I thought this was strange because the scanner/Unitrunker location is less than a mile from one of the sites and it is strong enough to overpower the other simulcast sites so it's not a distortion issue.
I started listening to the control channel audio and found that every once in a while the audio (cc data stream) stops for up to a second or so and there is either a dead carrier or what sounds like a ~1200 Hz square wave type tone. I tried to record this but of course it won't happen when I want it to. The attached file has some very short dropouts and tone but it can last up to about 2 seconds.
The system has four transmit sites and another four or so receive sites. Site backhaul is by microwave. I don't know if there is any wire or fiber to backup the microwave paths.
The CC audio dropouts/tone appears to occur at random intervals and durations so I don't think it is some type of simulcast alignment function. I can't tell if this is happening on all four transmit sites at the same time. Could the CC audio dropping out be a result of the controller failing or losing contact with sites? Has anybody else seen anything like this?
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