MARCS Voice Channels

[freqhunter]

I have run across something that has me scratching my head.

Last Saturday night Scannerbob and I where watching activity on the Elyria MARCS tower. My PSR-500 and his Pro-106 are programmed exactly the same. In fact he cloned his from mine. Several times OSP 47 came up with one voice channel shown on his, another shown on mine. This happened at least twenty times.

How, or way, would the same tower, programming, receivers & antennas show two different voice channels on the same transmission?

 

[hoser147]

It is interesting. This was at the same time and traffic? A shot in the dark but maybe they have them patched together.

 

[freqhunter]

Yep! Same time....... same sandbox!

 

[K8JSM]

Possibly he was hearing another repeater site simulcasting on another frequency. I'm new to MARCS, so I'm just offering a guess.

 

[Mike-KC8OWL]

A question and a thought - were both scanners programmed in Control Channel mode? If so, maybe one of the scanners is not representing the assigned voice frequency correctly. Since the system tells the receiver what frequency to tune to for the voice traffic in CC mode, maybe one of the scanners has a flaw in the code that interprets the assigned frequency and then displays same (the radio is tuned to one freq but is showing anohter).

Assuming the scanners were in CC mode, did you have a chance to program in all the assoicated voice frequencies and watch to see if the same thing happened?

Take care ... Mike

 

[freqhunter]

Both my PSR-500 and Scannerbob’s Pro-106 have been programmed exactly the same. In fact Scannerbob’s 106 was cloned from my 500. Neither where running in CC trunking. All frequencies are loaded in both.

 

[wlmr]

Were both frequencies broadcasting the info un-encrypted? If a clear and encrypted talkgroup are patched together, the system uses two frequencies. One of the frequencies carries the clear audio, one the encrypted. Both will indicate the same talkgroup on a scanner.

 

[freqhunter]

Both where in the clear.

We are going to add a 3rd 500/106 to the mix on Friday. It will be interesting to see if this happens again!

 

[Mike-KC8OWL]

Post the results .... I'm curious to see what happens.

I'll pay more attention to what my 2096 vs. 396 does on the same towers too