BCD436HP/BCD536HP: PL vs C (PL Tone vs CTCSS indicator)

[royldean]

This came up in the Pennsylvania discussion forum:

When listening to my local 2m repeaters, my 436 flashes "PL67.0" (or whatever the PL tone happens to be). However, when listening to the turnpike commission dispatch, it displays a solid "C136.5".

It appears that both of these are CTCSS tones, but why is there a distinction between the two indicators? Is PL only used for amateur bands?

 

[Jay911]

Are you certain it says "PL" on the display?

PL is "Private Line" which is (or was; I forget if it's lapsed) the Motorola trademark name for CTCSS. It's unlikely that Uniden would use that term in their radio.

I believe what's more likely is you're seeing C67.0 flashing on your 2M repeater, and C136.5 steady/"solid" on the dispatch channel. That's how mine displays tones, and here's what it means:

When it's flashing, it's because the tone is not programmed into the channel as stored in your radio - it's being auto-detected by the radio. When it's steady/solid, it's programmed into the radio and only signals matching that tone will be unmuted.

 

[royldean]

Are you calling me a liar!!!!



Of course I'm second guessing myself. You may be correct about me imagining "PL". But thanks for the explanation about the blinking - that makes sense.

 

[cmdrwill]

Some ham repeaters do not transmit a CTCSS 'tone' so the display/decoder in the scanner may false, that may be what you see displayed.

Jay119 IS correct, Motorola came up with Private Line back in the 60's and trademarked the system of encoding and decoding so you did not have to hear other users on the same frequency. In fact the first Private Line radio receivers had no carrier squelch in them..

Channel Guard
Quiet Channel
and others

CTCSS came along way later as other manufacture's played catch up. And they still could not call it PL.

 

[royldean]

Apparently I AM a liar. Just listened to a few minutes of the local 2m repeater. "C".

Sorry guys, my fault.