Repeater Hang Timer Beep?

[Ghost117]

I've heard this sound a lot on repeaters and I think it has something to do with the hang timer or something like that. I've seen some other posts about it but not explained fully. In the clip it's after a field unit is done transmitting and dispatch keys up the repeater while the hang timer is still transmitting. Hoping someone with more knowledge on repeaters can shed some light on the function of it.

Repeater Hang Timer Beep - Clyp

Listen to Repeater Hang Timer Beep | Clyp is the easiest way to record, upload and share audio.

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[n5ims]

I'm not able to play the audio but from your description it sounds like you're asking about a "Courtesy Beep" or "Courtesy Tone" (Repeater Courtesy Beeps and other Tone Information). They are placed on repeaters to let users know when the time-out timer has been reset and it's safe to transmit. Quoted is from HamUniverse.com (How to Use Amateur (Ham Radio) Repeaters- A New Ham's Guide to Repeaters) that explains it quite well.

Most repeaters have a "Courtesy Tone" (a short...beep or series of beeps) that will help in determining how long to pause. The courtesy tone serves two purposes. Repeaters have a time out function that will shut down the transmitter if the repeater is held on for a preset length of time (normally three or four minutes). This ensures that if someone's transmitter is stuck on for any reason, it won't hold the repeater's transmitter on indefinitely. (Don't laugh, many microphones get lodged in the fold of car seats and keep a repeater busy until it times out. Of course if it is not noticed soon by the mobile operator.....the control operator of the repeater may have to shut down the repeater until the problem is corrected.) When a ham is talking and releases the push-to-talk switch on their radio, the controller in the repeater detects the loss of carrier and resets the time-out timer. When the timer is reset, the repeater sends out the courtesy tone. If you wait until you hear this beep (normally a couple of seconds), before you respond, you can be sure that you are pausing a suitable length of time. After you hear the beep, the repeater's transmitter will stay on for a few more seconds before turning off. This is referred to as the "tail". The length of the tail will vary from repeater to repeater but the average is about 2 or 3 seconds.
You don't HAVE to wait for the "tail to drop" before keying up again, but make sure that you hear the courtesy tone (if used) before going ahead. Note: If you don't wait for the beep, the time-out timer may not reset. If you time-out the repeater, YOUR conversation AFTER the time-out will not be heard. The repeater time-out function does not care if you are still talking or not; and the station on the other end may rib you about hogging the machine and you will have wasted all those words! What is Doubling? When two stations try to talk at the same time on the same repeater, the signals mix in the repeater's receiver and results in a buzzing sound, squeal, distorted sound or severely jumbled and broken words.

While most are simply a short beep (or possibly two), others can be quite fancy. Some are even useful if you understand their "code". For example, in the old days when most radios were crystal based, it was often difficult to set the frequency to exactly the repeater's input frequency and some repeaters used a two tone sequence to help users adjust their crystals. A lower tone followed by a higher tone indicated that your frequency was a bit too high while a higher tone followed by a lower tone said it was too low, and when you got it right, both tones were the same pitch. Current radios don't need this, but you still might hear different tones or often now days different audio clips depending on what state the repeater is in. For example, there may be a unique tone sequence or spoken phrase indicating that a net is in progress (perhaps even what net it is) or is being linked to other repeater or repeaters. Some local repeaters will use a special tone or audio clip stating that the area is under a weather alert of some kind so folks know to monitor in case a SkyWarn net is activated, when the tone or clip will change to indicate a SkyWarn net is in progress.

 

[n5ims]

I wanted to keep this separate from the above information since it's a totally different, but related, topic. Many police (and similar) agencies will have an alert tone broadcast when the associated channel is to be kept clear during an active emergency. For example, they may close the channel when officers are involved in a chase or entering a location during an especially dangerous situation (felony arrest of multiple heavily armed suspects for example). This tone is unique and tells other officers that may not know about the incident to know that the channel is closed and to take their traffic elsewhere. Times like these, you don't want a traffic officer giving a long description of the car and driver being pulled over for a burnt out tail light delaying a "shots fired, officer down" call after breaching the door at the armed suspect call's location.

 

[nd5y]

The double beep when the dispatcher keys up is tone remote function tones.
It's not a ham type courtesy tone.
It's not made by the repeater.

 

[cmdrwill]

Defiantly Tone Remote keying tones. When the dispatcher keys up from the console and the tones are normally filtered out of a good working system so you would not hear them.

 

[12dbsinad]

Defiantly Tone Remote keying tones. When the dispatcher keys up from the console and the tones are normally filtered out of a good working system so you would not hear them.

Exactly. You "shouldn't" hear them. The only time you may is if you do a key, release, and then an immediate re-key.

 

[Giddyuptd]

Dont forget pre ptt side tone, consoles have them also which emits depending on the console, repeater settings, mdc with pre ptt side tone which can emit over air partially etc.

Bk relms newer p25 will actually emit their throw up sound ptt pre sidetone partially.

 

[n1das]

Defiantly Tone Remote keying tones. When the dispatcher keys up from the console and the tones are normally filtered out of a good working system so you would not hear them.

Definitely defiantly?

Exactly. You "shouldn't" hear them. The only time you may is if you do a key, release, and then an immediate re-key.

I've often heard this referred to as the "Motorola Tweet" sound when using tone operated remotes.

 

[12dbsinad]

I've often heard this referred to as the "Motorola Tweet" sound when using tone operated remotes.

There are instances that you will hear this "tweet" and it isn't specific to Motorola. What you're hearing is a blip of the guard and function tone. You can hear this a lot with older voted systems during dispatch re-key.

I miss this. And the voter clicks, partially muted MDC1200, etc.. newer radio systems are boring sounding, same mono tone, rag stuffed in noise sound.

 

[KG4INW]

I miss this. And the voter clicks, partially muted MDC1200, etc.. newer radio systems are boring sounding, same mono tone, rag stuffed in noise sound.

I still have a few users who, in certain quiet areas with their volume up all the way, will get the talk permit tone to echo and be audible over their first syllables!

 

[RKG]

As others have noted, what the OP is hearing is the "key up" function tones generated by the dispatch console channel card. Normally, a subscriber (or eavesdropper) won't hear those tones, because they are sent before the station's transmitter begins transmitting. When you will hear them is when the dispatcher quickly keys in response to a transmission by a subscriber, before the "tail" attached to the subscriber's call drops.

The audible "chink" sounds is the "High Level Guard Tone," a short burst at 2175 Hz. This is sometimes followed by a short burst of an EIA function tone, though on a simple key up of a one-channel station no EIA tone is required (and, in fact, was not present in the OP's clip). Finally, the console channel card will send a "Low Level Guard Tone" at the same 2175 Hz but at a low enough level that it won't be heard by human ears. The LLGT keeps the transmitter up as long as the consoles Tx button, pedal or icon is pressed.

 

[Project25_MASTR]

Exactly. You "shouldn't" hear them. The only time you may is if you do a key, release, and then an immediate re-key.

Depending on how the remote adapter is interfaced, that may be the exact issue. If you listen to the recording you can tell the repeater hasn't dekeyed yet. With some lower end repeater controllers, any audio coming in will be pass through to the transmitter. Some remote adapters are similar in that they just pass the function tone on the TX audio line (notching only 2175 Hz). If the repeater was keyed still and the function tone was simply repassed through to the TX audio of the repeater...remember, 2175 is being notched out, you get exactly what was just experienced.

As others have noted, what the OP is hearing is the "key up" function tones generated by the dispatch console channel card. Normally, a subscriber (or eavesdropper) won't hear those tones, because they are sent before the station's transmitter begins transmitting. When you will hear them is when the dispatcher quickly keys in response to a transmission by a subscriber, before the "tail" attached to the subscriber's call drops.

The audible "chink" sounds is the "High Level Guard Tone," a short burst at 2175 Hz. This is sometimes followed by a short burst of an EIA function tone, though on a simple key up of a one-channel station no EIA tone is required (and, in fact, was not present in the OP's clip). Finally, the console channel card will send a "Low Level Guard Tone" at the same 2175 Hz but at a low enough level that it won't be heard by human ears. The LLGT keeps the transmitter up as long as the consoles Tx button, pedal or icon is pressed.

The low level guard tone is quite audible. It is called a low level guard tone as it is 20-30 dB below the high level and function tones. The reason you don't hear it in regular audio transmissions is because there is a 2175 Hz notch filter in the remote adapter. Notches out the LLGT but merely attenuates the HLGT.

If you analyze the audio, you'll find the 40 ms 2175 Hz HLGT burst is present. You'll also find the 140 ms 1950 Hz F1 tone is present as well. What is not present is the continuous 2175 Hz LLGT. When normalized, you will also find the function tone is referenced at 0 dBm where the HLGT is referenced at -22 dBm (i.e. a notch filter providing roughly 22 dB of notch/attenuation at 2175 Hz).