Pl/dpl?

[dswaddling]

I searched the Software forum and found discussion about PLs and DPLs, but no explanation of simply what they mean, so I've come to this forum to ask: I have a PSR-300 scanner and am using Butel's ARC300 software to load it. There's a column in the frequency listings headed "PL/DPL." What does this mean and how does it work? Thanks!

 

[aaknitt]

Continuous Tone-Coded Squelch System - Wikipedia, the free encyclopedia

Continuous Tone-Coded Squelch System - The RadioReference Wiki

Squelch - Wikipedia, the free encyclopedia

DCS - The RadioReference Wiki

 

[rabidmoose57]

It's a squelch thing.......

Simply put it's a squelch feature that keeps groups of people using the same frequency from driving each other nuts. The PL refers to the Motorola Private Line analog squelching system. DPL refers to the same companies Digital Private Line squelch. Over the years instead of refering to all the varous squelching schemes individually, the terms PL & DPL have become the standard short hand for the whole community. It helps out when scanning, especially when you have several agencies nearby that use the same frequency, it lets you seperate out what you want to hear from the rest.Hope this helps.

 

[dswaddling]

That's very helpful. Does it mean that, in use, one would have to know the frequency of the tone that a particular group is using? And then, if that frequency is loaded into the scanner it will mask out all other transmissions on that channel?

 

[texasemt13]

Does it mean that, in use, one would have to know the frequency of the tone that a particular group is using?

Yes and No. Most scanners have a search feature. Some commercial radios require it to be programmed in. Depends on the receiver.

And then, if that frequency is loaded into the scanner it will mask out all other transmissions on that channel?

Yes, if the frequency AND tone (even though the tone is a separate frequency we simplify this by calling them "tones") are programmed in, then the receiver will only pick up that frequency with that specific tone. However, a useful feature of scanner is the search, which shows if other users might be switching to a different tone (the Texas Alcoholic Beverage Commission does this in the Dallas area). But, as I suspect you are experiencing, if two nearby agencies use the same frequency but different tones, they will not interfere with each other and only a receiver which is not discriminating between tones, will be able to tell that two groups occupy the same frequency.

 

[dswaddling]

That's a great explanation. Thanks so much!