Pl tone

[Joseph11]

Hmm, mine take less time than it takes for the person to start speaking, it is instant in all my Pro-92/2067 radios.

You're lucky, do you have the original PRO-92?

 

[Voyager]

If the police are transmitting, they're still "covering up all of the guys transmissions on my scanner" - you just don't hear it.

PL doesn't gain you anything - it loses you transmissions on which the PL isn't decodable.

But, if the PL isn't decodable, you won't be able to understand or hear the transmission you want to hear anyway, so no great loss other than not hearing the heterodyning or not hearing the transmissions you don't want to hear.

Joe M.

 

[Voyager]

Not all radios will do that. I think it depends on the sensitivity. Just about all of my amateur radios still have a tail at the end of a transmission, even with ctcss invoked. One of my handheld scanners which does not have CTCSS seems to eliminate the tail.

Most scanners that decode PL have search functions as well. If you don't have one, look at the database section of this site or a local web page that covers frequencies for your area. Most pages include the CTCSS/CDCSS info.

As for the above quote, most ham rigs do not have Reverse Burst (AKA STE or Squelch Tail Elimination). Just about all other radios do. IOW, hams are the exception, not the rule. Most ham radios also do not respond to Reverse Burst since they don't have the programming to recognize it exists. That's really sad since it is so easy to add to the decoder processing.

Joe M.

 

[SAR923]

In addition to what has already been mentioned about the advantages of having a CTCSS/DTS capable scanner, a big advantage for me is being able to eliminate other noises being picked up by the receiver that would make a frequency otherwise unmonitorable. I have several low band CHP frequencies that are picking up low level noise from things like my neighbor's light dimmer's. By using a CTCSS tone setting, the scanner scans and I only hear the CHP transmissions, not that blasted humming noise.

 

[loumaag]

You're lucky, do you have the original PRO-92?

I do; and a "B" model as well as a 2067 (which has the "A" model firmware). As I said, they all seem to decode CTCSS, DCS, and LTR stuff pretty much instantly. The original has all of the problems with Motorola systems that led to the "A" and "B" models. (But at least it will work after rebanding. :lol: )

 

[Al42]

But, if the PL isn't decodable, you won't be able to understand or hear the transmission you want to hear anyway

Why not? PL only prevents you from hearing certain transmissions - it doesn't allow you to hear transmissions you can't hear without it. You can still hear a transmission, even if the heterodyne between 2 transmitters is close enough to the PL frequency that your PL decoder won't work. And, if the signal strengths are close enough, or the capture ratio of your receiver is bad enough, you can understand both of them at the same time. Turning on PL at that point just squelches your receiver and you miss everything.

 

[Voyager]

Why not? PL only prevents you from hearing certain transmissions - it doesn't allow you to hear transmissions you can't hear without it. You can still hear a transmission, even if the heterodyne between 2 transmitters is close enough to the PL frequency that your PL decoder won't work. And, if the signal strengths are close enough, or the capture ratio of your receiver is bad enough, you can understand both of them at the same time. Turning on PL at that point just squelches your receiver and you miss everything.

Why not? Well, if the signal you want to hear is covered up be a stronger signal, nothing you do will allow you to hear it. Using PL prevents you from having to listen to signals you don't want to hear - like the one covering up the weaker signal. If the signal is heterodyning enough that the PL isn't decodable, you won't be able to understand the audio on the signal you want to hear. PL decoders are pretty good at ferretting out the correct code. If the signal doesn't pass a tone at 100 Hz, it most likely won't pass voice frequencies, either.

Joe M.