Tone out to unit mapping

[bhoglan]

Hey all,
I'm working on getting things working to monitor my fire department.
Reception is absolute garbage here on a vertical or discone so I used the database to find the transmitter location and pointed a Yagi out that way and connected it to an RTL-SDR dongle to monitor that one frequency. Success! It's like the dispatcher is sitting right next to me now.

So now I want to try and map the QC tones to their assigned units. I'm guessing that's not something I can just call and ask for. So I started recording in SDRConsole and played it back with a tone analyzer app running to get the frequencies. It works, mostly, but I'm hitting some cases where I'll hear two pairs of tones but they call out 3 units. Or two units and a station. Other cases have been different tones heard for the same unit call.

How do you all go about these mappings?
Also, is there generally any rhyme or reason to the assignments? Like department one always has (random number) 1513hz as the first tone then the unit is identified by the second tone?
Or is it usually more like "hey, tone pair 34 isn't assigned. That'll go to E91 now"?

 

[RaleighGuy]

How do you all go about these mappings?
Also, is there generally any rhyme or reason to the assignments? Like department one always has (random number) 1513hz as the first tone then the unit is identified by the second tone?
Or is it usually more like "hey, tone pair 34 isn't assigned. That'll go to E91 now"?

That is a great question that there is no standard answer for. I can tell you that there is usually a "rhyme or reason" to assignments, however it depends on the department and it's size. THIS LINK is a good example of how a larger department does it, but smaller departments might do it different. Learning the rhyme or reason is something you need to listen to and figure out for your department.

 

[IC-R20]

Like Raleigh says it varies with each department. The key is to just keep listening as much as you can and eventually you start to figure out things.

Lot of my local departs share a common Second tone with some having the stations spaced 20hz apart on the first tone but even then there’s quite a few exceptions.

Here’s a list from my own tone mapping efforts last year Fire Department Pager Tones

 

[dryfb]

Some of the ways I've seen two tone set up is one tone for medical calls, and one for fire so 2 different pairs but 1 department. One FD has an EMS tone, then for a fire/rescue call they send out the EMS tone and an additional tone for fire units.

For my county fire dispatch, each FD gets one pair, and each EMS station/dept gets one pair. The way they do it is that each town/city/village has the first tone the same for both EMS and fire. Then, the second tone in the pair is 457.9 for fire and 600.9 for EMS. So Green Springs fire is 832.5/457.9 Hz, then Station 7 EMS which is in Green Springs, uses 832.5/600.9. Might be easier to understand by looking at my wiki efforts; Seneca County (OH) - The RadioReference Wiki

Otherwise I've seen depts have no rhyme or reason to tone assignments and some seemingly picked willy nilly. I just kept on recording and finally noticed a pattern once I looked at all the tones next to each other.

 

[bhoglan]

Some of the ways I've seen two tone set up is one tone for medical calls, and one for fire so 2 different pairs but 1 department. One FD has an EMS tone, then for a fire/rescue call they send out the EMS tone and an additional tone for fire units.

For my county fire dispatch, each FD gets one pair, and each EMS station/dept gets one pair. The way they do it is that each town/city/village has the first tone the same for both EMS and fire. Then, the second tone in the pair is 457.9 for fire and 600.9 for EMS. So Green Springs fire is 832.5/457.9 Hz, then Station 7 EMS which is in Green Springs, uses 832.5/600.9. Might be easier to understand by looking at my wiki efforts; Seneca County (OH) - The RadioReference Wiki

Otherwise I've seen depts have no rhyme or reason to tone assignments and some seemingly picked willy nilly. I just kept on recording and finally noticed a pattern once I looked at all the tones next to each other.

This two tone pairs per unit scheme makes total sense! I did a ride along on a medic unit hundreds of years ago (2003?) and the sleeping rooms had a button on the wall where if it was pushed in you were EMS and if the button was out you were fire. It controlled which tone outs on the station PA would play in your room.

Thanks for the advice to both of you.

I'm thinking of an automated solution using Whisper speech to text to at least note the tones and units. It would also get the call type in the tone out narrative.
I'll add that to the "never gonna get to it" section of my to-do list.

Thanks again!

 

[IC-R20]

This two tone pairs per unit scheme makes total sense! I did a ride along on a medic unit hundreds of years ago (2003?) and the sleeping rooms had a button on the wall where if it was pushed in you were EMS and if the button was out you were fire. It controlled which tone outs on the station PA would play in your room.

Thanks for the advice to both of you.

I'm thinking of an automated solution using Whisper speech to text to at least note the tones and units. It would also get the call type in the tone out narrative.
I'll add that to the "never gonna get to it" section of my to-do list.

Thanks again!

There used to be a pretty decent program for that on the wiki here that did just that, without the transcription though. It would note the tones then record the audio after for the call narrative. TwoToneDetect - The RadioReference Wiki

 

[DC31]

The v75 of TTD has unknown tone sets detection built in.

Post in thread 'New TwoToneDetect in the works - Python based'
TwoToneDetect - New TwoToneDetect in the works - Python based

Enable it in the Configuration section.

 

[ofd8001]

There is no set pattern as a rule.

That said, a long time ago our county wanted to re-do tones from a Plectron based set to a Motorola Quick Call II. At the time, there were some 16 or so suburban fire departments.

To keep from a combination of tones conflicting and inadvertent opening of pagers, we set each department to have its own first tone. (The first tone would never be repeated as a second tone). Then, each station within a department had its own fire tone as well as its own EMS tone. (We wanted to alert volunteers about fires, but not med calls.)

If the second tone was higher in pitch than the first, it would be a medical call. Second tone lower would be for a fire.

As the years progressed, volunteers disappeared from the picture and a lot of department mergers happened. So the "system" pretty well got trashed, for lack of a better word.

 

[bc780l]

Try:
ComTekk Multi Tone Decoder
Been using for some time. Decodes properly and records files for later analysis.