“Fire Tone Outs” is a generic term for those multi-tone signals often used by Fire/EMS (and others) to page out responses. These could be used to alert fire stations, personnel or both depending on the agency. While there are several different technologies that have been used over the years the most common over the last few decades has been “Two Tone”. This means there are two sequential tones, followed by a voice message. Sometimes there would be a long third tone used as an alert beep as some radios did not have an internal beep, they would just open the squelch when the proper tones were decoded. This tech was used by several companies back in the day with names like Motorola, Reach, GE, Bell & Howell, Federal and, most famously, Plectron. While Motorola eventually won out, Plectron was the industry leader for years and was synonymous with volunteer firefighters from the 60’s thru the turn of the century. Even to this day, decades after Plectron closed its doors, the name is revered among firefighters, radio hobbyists and historians.
For the most part each manufacturer used a similar format, a steady tone lasting a few seconds followed quickly by another tone of a couple seconds. While the timings were sometimes different the underlying technology was pretty much the same. There was also a “Group Call” function that would set all the receivers with the same first tone (called the “A” tone or second tone (“B” tone”), this was sometimes called “Long A” or “Long B”, and used to open multiple stations or groups with a single tone rather than multiple sets of two-tones.
Originally mechanical devices were used to generate and decode the tones. These included struck devices sized to provide a specific tone, much like how a tuning fork works. They were then amplified and sent to the transmitter using devices much like an electric guitar pickup or even a microphone.
Some receivers used reeds that would vibrate upon application of the received tone and complete a circuit if the correct tone was heard. This method was used by Motorola using “Vibrasponders”. Plectrons usually used tuned coils instead of reeds.
Motorola had used a different protocol, in which two tones were superimposed for the first portion and another two tones superimposed for the second. This was the original “QuickCall”, sometimes referred to as “2 + 2”. Later they sold a simpler system with a single tone followed by another single tone they called QuickCall 2 (“QC2 or “1 + 1”). This was the same tech used by their competitors and is what is still used by countless fire departments to this day. If you listen to the tones used by the TV show “Emergency” it is the original Quick Call 2 + 2 that is used for the Station 51 tones.
Before the BC396T and BCD996T came out in 2004 scanner hobbyists would use surplus Plectron, Motorola or other brand alert receivers or pagers, set to the frequencies and codes used locally. One could also buy tone decoders and install them in scanners or receivers to accomplish this goal. The trick was however getting the tone code frequencies.
Before the Uniden’s came out, I had several Plectron alert receivers of a couple models. One I bought already set up on the regional Fire Mutual Aid system called MABAS. One of the CARMA members I knew would set up surplus “Pageboy” pocket pagers, usually for the same MABAS codes. I also had a couple surplus Motorola and Plectron radios on the channels used at work. They were great radios, even if you did not use the paging function. Wallace Radio would sell you a refurbished Plectron set up with the frequencies and tones you wanted or retune your radio to suit. As far as I know Bob Wallace is still in business and is the EXPERT on Plectrons. See WallaceRadio, LLC.
Speaking of Plectrons, they were made in a little town in Nebraska called Overton, along US-30 near Lexington. Their factory was pretty much the only industry in town aside from the grain elevator and was on Plectron Street. When the company closed some of its people moved over to another company in nearby Lexington, now known as Veetronix, as far as I know there are still making alert receivers built on a Uniden BC350 chassis.
When I was a firefighter, I had one of the ubiquitous Minitor pagers assigned to me and was able to obtain some of the old Plectrons, rescued from the trash. They still worked fine and even the batteries worked. Before that, when I was in school still, my dad had a couple Plectrons from the town we lived in, one for fire calls and another tuned to the police channel.
After the BCD396T and BCD996T came out in 2004 I started to get really interested in Fire Tone Outs. About the same time, we were installing a new console for the 9-1-1 Center at work and one of the components was alert paging for the Fire Department. I had to figure out the codes needed for our town and all our neighbors we relied upon for mutual aid. Most had no idea what the tones were, all they had were the “Cap Codes”. These codes were derived from a group and code within that group so one needed a chart to figure it out. I got a copy of the CentraCom console manual (CentraComs were used by several of the other agencies in the area). That had a decent chart for deciphering these codes.
There was a good reason Motorola made it so difficult to figure these out. In the old days with mechanical reeds there was a limit to the number of reeds available, so they were sold in groups. Each group had reeds with specific tones that would not be resonate with each other. This carried over to electronically generated tones, while this eliminated the technical limitation on the codes used limiting the groups was a way to generate more income from those agencies that needed more than a single Group.
Our new console system from ModuCom had no such limitations, one just programmed in the actual tones needed to accomplish the goal, regardless of the manufacturer of the alert receivers. Some of our partners had Plectron gear (like us), others were all Motorola, some had Federal. There was even some agencies used DTMF (Touch-tone) paging.
For a couple weeks I studied the tone charts and was fascinated with it and was eventually able to figure out the codes used by all the departments in the area. I was then able to program them all into the new consoles. Concurrently I was looking for a way to decipher this stuff over the air. I tried to buy a Midian decoder that was offered at the time, but they would never respond to any inquiries. They had terrible customer support back then and would hang up on me when I called to ask about the product advertised on their website. It was a decoder that would decode and display the tones over the air, and I suspect it was never actually developed for sale.
I then was told about a program called Audition by Adobe and a similar program called Audacity that was open source. I tried both but preferred Audition so bought it. I paired that with the fabulous ScannerRecorder software. I would set up a scanner on a fire frequency and record it with ScannerRecorder for a time, this could be over a few days or even a month. I would then open the resulting recordings with Audition and view the waveforms. Two Tone transmissions were easy to spot visually, and you would just click on the tone’s waveform and the software would display the tone. I got so good at this that I could view a waveform and know it was one I saw and measured before. I could even tell what transmitter they were using as some had characteristic artifacts that would fingerprint them.
Pretty soon I had figured out all the known tones used within the range of my scanners at home, so I brought a radio and a laptop to work and connect the radio to the antenna at the top of the tower and let ScannerRecorder do its thing. I then was able to decode fire tones from a 4-state area.
Now this method had a limitation. The software would indicate the tone but there was enough tolerance, usually a few percentage points, so that determining the exact tone transmitted was sometimes difficult. For instance, 615.8 Hz. Is a common Plectron tone while 617.4 is a common Motorola one. If the tone measured was 616.2 for example, was it the Plectron or Motorola one? For scanners it usually didn’t matter as the tolerances were wide but for work purposes it had to be more exact as that could be a life-safety issue. I then developed a chart of the common tones, color coded by manufacturer. By looking at both tones I could usually figure out at least one of the tone’s origins, and then extrapolate the other’s true code. There was also the timings to look at, different companies systems used slightly different timings for the first and second tones and the spacing between them.
While this was effective it was not absolute. As newer consoles and encoder systems were developed that get away from the limitations in the tones it was common to see tones from different manufacture’s preferred tone sets mixed together. As a Plectron agency we tended to use integer tones like 1200/1400 Hz. while our neighbor used Motorola codes like 979.9/651.9. Later one of the departments needed new tones as they were getting opened by a distant agency on the same freqs that had the same tones, so we switched them to a mixed Plectron/Reach code as we liked the way they sounded together. We really wanted to use the Station 51 tones, but they were QC-1 and we needed to stay with the format. (Yes, we were that vain…)
After all this I wrote an article on how to find and decode fire tones for the CARMA Newsletter and then was approached by Monitoring Times to write an article for them. This ended up being the cover article for the August 2006 edition.
Here in the Phoenix area where I live now the use of Two-Tone paging is very limited, calls at the main airport (Sky Harbor) occasionally use it and a few more rural agencies use it as well. Back in the suburban Chicago area Two-Tone was almost universally used but is much less so these days with trunking systems and other tech being used. It had been fun figuring out the codes, but Uniden took all that fun away when they introduced the ability to search for fire tone out codes directly on the radio, it was then too easy to be fun anymore!
For the most part each manufacturer used a similar format, a steady tone lasting a few seconds followed quickly by another tone of a couple seconds. While the timings were sometimes different the underlying technology was pretty much the same. There was also a “Group Call” function that would set all the receivers with the same first tone (called the “A” tone or second tone (“B” tone”), this was sometimes called “Long A” or “Long B”, and used to open multiple stations or groups with a single tone rather than multiple sets of two-tones.
Originally mechanical devices were used to generate and decode the tones. These included struck devices sized to provide a specific tone, much like how a tuning fork works. They were then amplified and sent to the transmitter using devices much like an electric guitar pickup or even a microphone.
Some receivers used reeds that would vibrate upon application of the received tone and complete a circuit if the correct tone was heard. This method was used by Motorola using “Vibrasponders”. Plectrons usually used tuned coils instead of reeds.
Motorola had used a different protocol, in which two tones were superimposed for the first portion and another two tones superimposed for the second. This was the original “QuickCall”, sometimes referred to as “2 + 2”. Later they sold a simpler system with a single tone followed by another single tone they called QuickCall 2 (“QC2 or “1 + 1”). This was the same tech used by their competitors and is what is still used by countless fire departments to this day. If you listen to the tones used by the TV show “Emergency” it is the original Quick Call 2 + 2 that is used for the Station 51 tones.
Before the BC396T and BCD996T came out in 2004 scanner hobbyists would use surplus Plectron, Motorola or other brand alert receivers or pagers, set to the frequencies and codes used locally. One could also buy tone decoders and install them in scanners or receivers to accomplish this goal. The trick was however getting the tone code frequencies.
Before the Uniden’s came out, I had several Plectron alert receivers of a couple models. One I bought already set up on the regional Fire Mutual Aid system called MABAS. One of the CARMA members I knew would set up surplus “Pageboy” pocket pagers, usually for the same MABAS codes. I also had a couple surplus Motorola and Plectron radios on the channels used at work. They were great radios, even if you did not use the paging function. Wallace Radio would sell you a refurbished Plectron set up with the frequencies and tones you wanted or retune your radio to suit. As far as I know Bob Wallace is still in business and is the EXPERT on Plectrons. See WallaceRadio, LLC.
Speaking of Plectrons, they were made in a little town in Nebraska called Overton, along US-30 near Lexington. Their factory was pretty much the only industry in town aside from the grain elevator and was on Plectron Street. When the company closed some of its people moved over to another company in nearby Lexington, now known as Veetronix, as far as I know there are still making alert receivers built on a Uniden BC350 chassis.
When I was a firefighter, I had one of the ubiquitous Minitor pagers assigned to me and was able to obtain some of the old Plectrons, rescued from the trash. They still worked fine and even the batteries worked. Before that, when I was in school still, my dad had a couple Plectrons from the town we lived in, one for fire calls and another tuned to the police channel.
After the BCD396T and BCD996T came out in 2004 I started to get really interested in Fire Tone Outs. About the same time, we were installing a new console for the 9-1-1 Center at work and one of the components was alert paging for the Fire Department. I had to figure out the codes needed for our town and all our neighbors we relied upon for mutual aid. Most had no idea what the tones were, all they had were the “Cap Codes”. These codes were derived from a group and code within that group so one needed a chart to figure it out. I got a copy of the CentraCom console manual (CentraComs were used by several of the other agencies in the area). That had a decent chart for deciphering these codes.
There was a good reason Motorola made it so difficult to figure these out. In the old days with mechanical reeds there was a limit to the number of reeds available, so they were sold in groups. Each group had reeds with specific tones that would not be resonate with each other. This carried over to electronically generated tones, while this eliminated the technical limitation on the codes used limiting the groups was a way to generate more income from those agencies that needed more than a single Group.
Our new console system from ModuCom had no such limitations, one just programmed in the actual tones needed to accomplish the goal, regardless of the manufacturer of the alert receivers. Some of our partners had Plectron gear (like us), others were all Motorola, some had Federal. There was even some agencies used DTMF (Touch-tone) paging.
For a couple weeks I studied the tone charts and was fascinated with it and was eventually able to figure out the codes used by all the departments in the area. I was then able to program them all into the new consoles. Concurrently I was looking for a way to decipher this stuff over the air. I tried to buy a Midian decoder that was offered at the time, but they would never respond to any inquiries. They had terrible customer support back then and would hang up on me when I called to ask about the product advertised on their website. It was a decoder that would decode and display the tones over the air, and I suspect it was never actually developed for sale.
I then was told about a program called Audition by Adobe and a similar program called Audacity that was open source. I tried both but preferred Audition so bought it. I paired that with the fabulous ScannerRecorder software. I would set up a scanner on a fire frequency and record it with ScannerRecorder for a time, this could be over a few days or even a month. I would then open the resulting recordings with Audition and view the waveforms. Two Tone transmissions were easy to spot visually, and you would just click on the tone’s waveform and the software would display the tone. I got so good at this that I could view a waveform and know it was one I saw and measured before. I could even tell what transmitter they were using as some had characteristic artifacts that would fingerprint them.
Pretty soon I had figured out all the known tones used within the range of my scanners at home, so I brought a radio and a laptop to work and connect the radio to the antenna at the top of the tower and let ScannerRecorder do its thing. I then was able to decode fire tones from a 4-state area.
Now this method had a limitation. The software would indicate the tone but there was enough tolerance, usually a few percentage points, so that determining the exact tone transmitted was sometimes difficult. For instance, 615.8 Hz. Is a common Plectron tone while 617.4 is a common Motorola one. If the tone measured was 616.2 for example, was it the Plectron or Motorola one? For scanners it usually didn’t matter as the tolerances were wide but for work purposes it had to be more exact as that could be a life-safety issue. I then developed a chart of the common tones, color coded by manufacturer. By looking at both tones I could usually figure out at least one of the tone’s origins, and then extrapolate the other’s true code. There was also the timings to look at, different companies systems used slightly different timings for the first and second tones and the spacing between them.
While this was effective it was not absolute. As newer consoles and encoder systems were developed that get away from the limitations in the tones it was common to see tones from different manufacture’s preferred tone sets mixed together. As a Plectron agency we tended to use integer tones like 1200/1400 Hz. while our neighbor used Motorola codes like 979.9/651.9. Later one of the departments needed new tones as they were getting opened by a distant agency on the same freqs that had the same tones, so we switched them to a mixed Plectron/Reach code as we liked the way they sounded together. We really wanted to use the Station 51 tones, but they were QC-1 and we needed to stay with the format. (Yes, we were that vain…)
After all this I wrote an article on how to find and decode fire tones for the CARMA Newsletter and then was approached by Monitoring Times to write an article for them. This ended up being the cover article for the August 2006 edition.
Here in the Phoenix area where I live now the use of Two-Tone paging is very limited, calls at the main airport (Sky Harbor) occasionally use it and a few more rural agencies use it as well. Back in the suburban Chicago area Two-Tone was almost universally used but is much less so these days with trunking systems and other tech being used. It had been fun figuring out the codes, but Uniden took all that fun away when they introduced the ability to search for fire tone out codes directly on the radio, it was then too easy to be fun anymore!
