What is a tone?

[emt_531]

I noticed that several CalFire frequencies had a "tone" associated with them. What exactly is a tone, and does it need to be programmed in with the frequency. I have RS Pro-96

 

[SAR923]

A tone is short for a CTCSS tone, a subaudible tone that tells a receiver to only open squelch if it sees the right tone. CDF (I refuse to call them CalFire ) uses multiple tones on the same frequency to cut down on stations and units having to listen to calls from other ranger units. You don't have to program in the tones unless you only want to listen to the specific ranger unit that uses that tone and don't want to hear any other traffic on that frequency. With no tone, you just hear everything that's in range, which can be quite a lot given CDF's excellent repeater system.

 

[Twister_2]

Kind of like Specific Area Message Encoder...or SAME for weater radio.

 

[n1das]

What exactly is a tone

http://en.wikipedia.org/wiki/Tone

 

[jcop225]

The PRO-96 might not take tones, I have the PRO-95 and it does not, which is most annoying when trying one station that is being crossed by another. In my opinion if you could program in tones you'd know.

 

[Dubbin]

The PRO-96 might not take tones, I have the PRO-95 and it does not, which is most annoying when trying one station that is being crossed by another. In my opinion if you could program in tones you'd know.

The PRO-96 does except CTCSS/DCS tones.

 

[chrismol1]

Listen to the EMS or fire dispatch frequency, you will hear 2 sounds that sound like when you press the numbers on a telephone. Then the transmission will come throught from dispatch with the message. Like say there are a bunch of fire districts in one county as there are everywhere. and they ALL use the SAME dispatch frequency. It wouldnt be practical to alert someone to a fire or EMS call that is on the otherside of the county. So each district has their own tones that set off their Minitor pager. that allows them to only here the call directed in their vicinity of their district. its bascially SelCal, selective calling

 

[SAR923]

No, chris, you've got it wrong. The tones on CDF frequencies are CTCSS tones so that stations from other ranger units do not have to listen to distant ranger units that are on the same frequency. What you are describing has nothing to do with CTCSS tones. They are selective two tone combinations that only set off the radios at specific station or on specific pagers. You can have no CTCSS tones on the frequency but the receiver will only be activated when it hears the correct two tone combination.

 

[chrismol1]

No, chris, you've got it wrong. The tones on CDF frequencies are CTCSS tones so that stations from other ranger units do not have to listen to distant ranger units that are on the same frequency. What you are describing has nothing to do with CTCSS tones. They are selective two tone combinations that only set off the radios at specific station or on specific pagers. You can have no CTCSS tones on the frequency but the receiver will only be activated when it hears the correct two tone combination.

Yeh, i've been talking about the other kinda tones not CTCSS tones
yeh CTCSS

 

[gmclam]

CT programming

emt_531, you do not "need" to program the tones, but I find it helps properly identify what I am receiving - especially with CAL FIRE. I am not sure where in California you are, or what you monitor, so I am not able to provide an exact example. But for me, using a PRO-97, I have the following programmed:

x00 151.4000 110.9 CAL FIRE OROVILLE
x01 151.4000 103.5 CAL FIRE MARIPOSA
x02 151.4000 search CAL FIRE TAC 10

x10 151.4600 136.5 CAL FIRE SANTA ROSA
x11 151.4600 123.0 CAL FIRE MARIPOSA
x12 151.4600 search CAL FIRE TAC 12

In my examples the order of programming is important; in that the "search" mode (no tone) is programmed last. I program a frequency several times (in these examples 3) and program specific CT values. If no CT is received, it must be a TAC channel.

This is just one example of using CT programming. There are many other applications.