Cambridge MA P-25 Radio System

[KB1OQA]

I have Cambridge MA's P-25 Radio System programmed into my Uniden BCD996XT Scanner. Although I live some distance away, I am receiving some of the Talkgroups on this system. I'm using an outside antenna connected to the radio with LMR-400 cable.

Some of the talkgroups generate actual communications I can hear, while others show on the screen with no audio present.

It appears that there may be a mixture of analog and digital control channels programmed. My question is:
If I installed just the five control and alternate P-25 control channels, would signals be received, or is it necessary to install the voice channels as well?

 

[KB1VLA]

A true P25/9600 bps system cannot have analog talkgroups, you may be receiving talkgroups that are data only, and not voice. But to answer your question, only the CCs need to be programmed into your scanner, the voice channels don't need to be added.

 

[ecps92]

Only program the info from the P25 system, what little is left on the analog system will be moved over. Police/Fire and EMS are already on the P25 System. If you have problems, on the 800 you might want to listen to the UHF Patched channels instead

I have Cambridge MA's P-25 Radio System programmed into my Uniden BCD996XT Scanner. Although I live some distance away, I am receiving some of the Talkgroups on this system. I'm using an outside antenna connected to the radio with LMR-400 cable.

Some of the talkgroups generate actual communications I can hear, while others show on the screen with no audio present.

It appears that there may be a mixture of analog and digital control channels programmed. My question is:
If I installed just the five control and alternate P-25 control channels, would signals be received, or is it necessary to install the voice channels as well?

 

[KB1OQA]

Not to belabor this, but:

RR has a list of Cambridge P-25 CC's comprised of one main and three alternates, while another site has a listing of one main and one alternate CC. Which is the best to use?

Thanks for those who replied - Good Info.

 

[KB1OQA]

One Final Question: Any changes required as far as the Band Plan is concerned? I checked that setting, and all I saw was frequencies. I think, based on other areas, there should be choices, such as Standard, Splinter, Rebanded 800, and Custom.

I wasn't the one that set this up, so any added info would help.

 

[ecps92]

IF the site with the two is
City of Cambridge - Scan New England Wiki
the reason for two is that those have been the only two actually heard in use as a Control Channel, Until they use others, they would not be listed.

My limited understanding of P25 systems is that Any of the Frequencies could become potential alternate control channels. Not sure how true that is, but... YMMV

Not to belabor this, but:

RR has a list of Cambridge P-25 CC's comprised of one main and three alternates, while another site has a listing of one main and one alternate CC. Which is the best to use?

Thanks for those who replied - Good Info.

 

[gordon115]

If you have only the P25 control channels programmed the radio shouldn't be receiving analog talk groups, 860.7875 is the analog control channel don't program that into your radio unless you want to hear the analog system. There is very little activity left on analog and most of what is left is simulcast on the P25 system.

If the radio is stopping on a talk group and you don't hear audio the signal is probably too weak at your location or it could be an encrypted or data transmission; some PD & FD talk groups use encryption but not very often. In Wayland you are probably on the fringe of where the system can be heard on a scanner.

Gordon

 

[jmorrissey23]

All traffic on the Analog system was terminated at the beginning of the month, therefore you should make sure you have 857.2875 programmed in as the Control Channel and not 860.7875

 

[jmorrissey23]

My limited understanding of P25 systems is that Any of the Frequencies could become potential alternate control channels. Not sure how true that is, but... YMMV

I believe that is only true with Harris P-25 systems. Moto P25 systems should have a limit to four control channels at a time.

 

[ecps92]

Ahhh, yes that is where I heard that. thanks.

I believe that is only true with Harris P-25 systems. Moto P25 systems should have a limit to four control channels at a time.