So here's a weird one; I didn't know this was even a thing among analog FM systems.
The local law enforcement dispatch uses a single analog narrowband VHF frequency (155.5350 MHz) on their repeater output. They have several repeaters covering the county; two sites are above the local town and both completely blanket the local area with their signal. Both of these sites have the same transmitter power, both transmit the same CTCSS tone, and both transmit at the same time with all radio traffic.
I sometimes use an XTS3000 to listen in. When it receives traffic on this particular frequency, the signal is, I'm assuming, getting wiped out by the two transmitters being used simultaneously. It will receive clearly for a couple of seconds, then static quickly builds until the audio goes completely quiet, then will suddenly receive clearly for a couple of seconds, then static, then nothing, and repeat. It will do this cycle repeatedly in perfect time as long as the frequency is being used. This issue only started in the last few months; prior to that, never had a problem.
I can forcefully attenuate the signal by gripping the radio's antenna in my hand, and doing this causes the received audio to stop the on/off cycle described above, and I then hear everything clearly. So I am assuming that this fade in and out issue is due to the receiver getting overloaded by the two different equal signals off the two repeaters covering the local area.
For comparison, I have a Uniden SDS200 with an outside antenna that can actually "see" THREE of this system's repeater sites, all of which are transmitting same frequency, same CTCSS tone, and it is able apparently to ignore two of them and clearly receive just one no problem.
So finally the question: is there a setting of some sort that I'm missing in my XTS3000 CPS that somehow enables the radio to properly deal with the simulcast interference it's getting? Or is that ability too new for this model radio to do? Or is this maybe a problem with the two repeater site transmitters somehow not being configured correctly and causing the issues?
Interesting side note- the local fire dispatch uses the exact same setup as far as simulcasting sites with same analog frequency and CTCSS tone, but the XTS3000 has no problem receiving it clearly. Not sure if maybe the two fire transmitters are somehow more synced somehow so they don't have the same problem as the law transmitters, or maybe they just have different transmit power so one always wins, or some other cause.
Thank you for your help figuring this one out!
The local law enforcement dispatch uses a single analog narrowband VHF frequency (155.5350 MHz) on their repeater output. They have several repeaters covering the county; two sites are above the local town and both completely blanket the local area with their signal. Both of these sites have the same transmitter power, both transmit the same CTCSS tone, and both transmit at the same time with all radio traffic.
I sometimes use an XTS3000 to listen in. When it receives traffic on this particular frequency, the signal is, I'm assuming, getting wiped out by the two transmitters being used simultaneously. It will receive clearly for a couple of seconds, then static quickly builds until the audio goes completely quiet, then will suddenly receive clearly for a couple of seconds, then static, then nothing, and repeat. It will do this cycle repeatedly in perfect time as long as the frequency is being used. This issue only started in the last few months; prior to that, never had a problem.
I can forcefully attenuate the signal by gripping the radio's antenna in my hand, and doing this causes the received audio to stop the on/off cycle described above, and I then hear everything clearly. So I am assuming that this fade in and out issue is due to the receiver getting overloaded by the two different equal signals off the two repeaters covering the local area.
For comparison, I have a Uniden SDS200 with an outside antenna that can actually "see" THREE of this system's repeater sites, all of which are transmitting same frequency, same CTCSS tone, and it is able apparently to ignore two of them and clearly receive just one no problem.
So finally the question: is there a setting of some sort that I'm missing in my XTS3000 CPS that somehow enables the radio to properly deal with the simulcast interference it's getting? Or is that ability too new for this model radio to do? Or is this maybe a problem with the two repeater site transmitters somehow not being configured correctly and causing the issues?
Interesting side note- the local fire dispatch uses the exact same setup as far as simulcasting sites with same analog frequency and CTCSS tone, but the XTS3000 has no problem receiving it clearly. Not sure if maybe the two fire transmitters are somehow more synced somehow so they don't have the same problem as the law transmitters, or maybe they just have different transmit power so one always wins, or some other cause.
Thank you for your help figuring this one out!