Are there any circumstances I would need to program a PL tone with the associated frequency in my scanner (RS Pro-164)?
PL Tone programming question
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tvengr
Well Known Member
If there is more than one user on the frequency, the tones can be used to monitor each user separately. Quite often, fire departments will have several repeaters using the same frequency and you will be able to select each repeater separately. With no tone, you will be using the squelch adjustment to quiet the noise between transmissions. With a PL tone, there will be no noise no matter what the squelch setting is since the squelch will open only when receiving the PL tone.
I just found out some of the frequencies from one of the communication centers in my area uses a RAN digital PL tone.
Since my RS Pro-164 is an analog scanner, I am assuming it will not pick up digital PL tones?
Since my RS Pro-164 is an analog scanner, I am assuming it will not pick up digital PL tones?
tvengr
Well Known Member
A frequency using a RAN (Radio Access Number) is NXDN which is a digital format which your scanner cannot receive. PL (Private Line) is the Motorola name for CTCSS (Continuous Tone-Coded Squelch System). They are one and the same. Likewise, DPL (Digital Private Line) is the Motorola name for DCS (Digital-Coded Squelch). They are one and the same also. Although your scanner is analog, it can use DPL or DCS.
That's what I figured, so for those on the NXDN, I won't bother programming the PL tone.
tvengr
Well Known Member
NXDN uses RAN, not PL. You can't receive NXDN on your scanner anyway, with or without a RAN.
Right, that is what I meant to say.
Serves me right for trying to put frequencies in ARC300 at 3a without first having a cup of coffee
I found that most of the FAA ATC frequencies have CSQ listed under the tone here on radio reference. From what I understand, CSQ stands for Constant Squelch, which means the frequency is constantly open (Please do correct me, I am still learning ).
Does this mean I can leave the PL/DPL column blank in ARC300 instead of on search?
).Does this mean I can leave the PL/DPL column blank in ARC300 instead of on search?
paulears
Member
CSQ is carrier squelch, as in the gate opens on reception of a carrier above a certain level - with or without audio. any form of selective squelch is probably of little use for people interested in hearing interesting stuff. I suppose it could be useful on a system that shares interesting stuff with the dull? A local user has the engineers and the cleaners on the same frequency with different tones, and the constant "number 3 is done", "number 49 is done", "36 has run out of toilet paper" gets uninteresting very quickly.
Thanks for the explanation.
Listening to ATC is interesting to me personally (and I am sure some other users on this forum), so no issue with the above for me
tvengr
Well Known Member
Carrier squelch works this way: When there is no signal present in a FM system, you hear RF noise. The RF noise is amplified and changed to a DC switching voltage which turns off the audio amp so you do not hear the noise. The squelch control is adjusted to provide the proper amount of noise needed to turn off the audio amp. When a signal is received, the receiver is quieted and the noise disappears. With no noise, the audio amp is turned back on to monitor a transmission. The squelch control should be turned up just enough to quiet the noise with no signal. Past that point, only signals of a higher level will be received and you will miss any transmissions with inadequate signal strength to open the squelch.
ecps92
Member
AM (Air Traffic) would not use PL/DPLI found that most of the FAA ATC frequencies have CSQ listed under the tone here on radio reference. From what I understand, CSQ stands for Constant Squelch, which means the frequency is constantly open (Please do correct me, I am still learning
Does this mean I can leave the PL/DPL column blank in ARC300 instead of on search?
PL/DPL is for FM frequencies
That is handy to know.
Another question I had is can you listen to a frequency without programming a PL tone?
I ask because some of the aviation related frequencies that I would like to listen to uses DMR as the PL tone.
Since my Pro-164 scanner is analog, I was wondering if I could program the frequency without programming the PL tone, since it is digital.
I ask because some of the aviation related frequencies that I would like to listen to uses DMR as the PL tone.
Since my Pro-164 scanner is analog, I was wondering if I could program the frequency without programming the PL tone, since it is digital.
You are confusing modes with squelch tones. Your scanner will not receive any digital modes (DMR,NXDN, P25).
On an analog mode channel you can use pl or digital pl to filter out other users.
Aviation AM channels 108-136 mhz do not use any form of pl tones.
On an analog mode channel you can use pl or digital pl to filter out other users.
Aviation AM channels 108-136 mhz do not use any form of pl tones.
I was not specific enough and I apologize in advance for that.
I also have a bank of airline ground ops and some have this listed
under tone:
CC 7
TG 1001
SL 1
Since I know that is a digital tone (possibly connected to a trunking system) which my scanner cannot decode (Analog scanner), I was wondering if I could program the frequency in without the tone.
You are still confusing mode with squelch tone.
If you see "CC" (color code) in a listing, then that frequency is DMR. Your scanner cannot decode DMR. If you program that frequency in (and are close enough to hear it) you will hear a loud annoying buzzing sound.
Now I understand and it is what I figured before I posted.
Not sure why it did not click until now.
paulears
Member
For scanner users, the aim is usually to hear as much as possible. All of the tone systems are designed to do the reverse - NOT annoy you with messages that are not for you. With aviation the only sorts of tomes you could hear on HF long range links are tones designed to identify the sender - so an airline ops centre might find it useful to know which aircraft is calling them. On normal VHF air band, just forget tones - they're not in use. On non-digital business channels again, you won't need tones.
