Identifying Transmission

[Lyman]

As you can see from the attached, how can I tell if I am listening to Salisbury or Plymouth?

Thanks,

Lyman

 

[Tryton]

you would have to program in the PL tone, because both use the same freq's..

 

[garys]

Where are you listening from? There aren't too many parts of the state where you are likely to hear both.

Gary

 

[LPD7]

If you can hear Both, put on the ATT, this will block out the Distant signals, and you will here only the one you are closest to if you cant program in the CT PL Code

 

[Lyman]

Thanks Gary, LPD7. I am in Methuen, which would pick up both Plymouth and Essex County. LPD7, I see you're in Lowell, right around the corner.

I am still curious though as to how one identifies the PL Tone.

Lyman

 

[Junior08]

483.7375 PL 203.5 is Plymouth County Sheriff's Dept/BCI (Bureau of Criminal Intent)

483.7375 PL 146.2 is Salisbury Police.

The PL tone is programmed into EVERY radio that is used by each department. That is, The Plymouth County Sheriff's Dept has EVERY radio in their fleet programmed with a PL tone of 203.5, so there is no interference from another agency that may be using the same frequency. Same with Salisbury.

If you have a scanner that decodes PL tones, set it to 483.7375 and see what PL tone it decodes. This will tell you who you are hearing. I'm guessing you will more than likely be hearing Salisbury, based on your location.

 

[LPD7]

If you listen closley, you will hear a hum, almost "under" the transmission, that is the "PL Hum" and it carries a code that allows members of that frequency to hear only on THAT PL code. For Example, Methuen Police use 482.4625 witha PL of 146.2 (Common about NE MA Towns) and they only people that can transmist to Methuen Units needs the PL code to do so (Dont try and talk on the radio though ) if you program in the PL Code, you WILL NOT hear anything that does NOT carry that PL Tone on their transmission.

What kind of Scanner do you have?

 

[Lyman]

483.7375 PL 203.5 is Plymouth County Sheriff's Dept/BCI (Bureau of Criminal Intent)

483.7375 PL 146.2 is Salisbury Police.

The PL tone is programmed into EVERY radio that is used by each department. That is, The Plymouth County Sheriff's Dept has EVERY radio in their fleet programmed with a PL tone of 203.5, so there is no interference from another agency that may be using the same frequency. Same with Salisbury.

If you have a scanner that decodes PL tones, set it to 483.7375 and see what PL tone it decodes. This will tell you who you are hearing. I'm guessing you will more than likely be hearing Salisbury, based on your location.

Thank you, Mark. The PRO-96 will decode these and I see that they are listed in the database.

483.7375 is silent for the moment but when listening to some active frequencies I notice that some but not all will have "CT xxx.y" as is the case with the Cambridge Police on 470.31250 which will have "CT 131.8". What is the "CT 131.8" that I see? Curious also why, as mentioned, this additional number will be present on some but not all transmissions.

Thanks again,

Lyman

 

[Lyman]

If you listen closley, you will hear a hum, almost "under" the transmission, that is the "PL Hum" and it carries a code that allows members of that frequency to hear only on THAT PL code. For Example, Methuen Police use 482.4625 witha PL of 146.2 (Common about NE MA Towns) and they only people that can transmist to Methuen Units needs the PL code to do so (Dont try and talk on the radio though ) if you program in the PL Code, you WILL NOT hear anything that does NOT carry that PL Tone on their transmission.

What kind of Scanner do you have?

Matt, thank you. Is it the frequency that is common around NE MA Towns or the PL?

Thanks again for the help!

Lyman

 

[ecps92]

CT vs PL

Yes, Bearcat call PL a CT

PL - Private Line [Motorola Terminoloy]
CG - Channel Guard [General Electric Terminology]
CTCSS - Continuous Tone Coded Squelch System [EIA Standard] http://en.wikipedia.org/wiki/CTCSS <<- Great Reading source
CT - Connect Tone or Channel Tone [Bearcat]

Thank you, Mark. The PRO-96 will decode these. 483.7375 is silent for the moment but when listening to some active frequencies I notice that some but not all will have "CT xxx.y" as is the case with the Cambridge Police on 470.31250 which will have "CT 131.8". Is the "CT 131.8" that I see that PL Tone? Curious also why, as mentioned, this additional number will be present on some but not all transmissions.

Thanks again,

Lyman

 

[LPD7]

The PL Code is Common around that Area, since the 1970's the NEMLEC Affiliated towns have utilized the 146.2 PL Code, from the Lowell Area all the way up to The North Shore

 

[Lyman]

Thank you to everyone for your help in answering this question; much appreciated!