Alert tone added to CDM1250

[Andy2712]

We would like to add an emergency alert tone to our CDM1250's that we would be able to broadcast over a fire ground channel from a command vehicle. Something like a warble tone would great and maybe just a single button for the boss to press. I don't want to confuse them too much. Is there a simple encoder or similar we could add to the radios? Thanks.

Andy

[pfd radio]

We programmed a 1000 Hz tone and send it out as a call alert. You can encode tones through the QCII calling feature. I think it is more than a single press on our radio.

It is a radio call button and then the enter/select button and then PTT on the mic - (we are using it on CDM1550's, but I don't see why you could not do that with 1250's)

We use MDC1200 signaling and have any "ALL CALL" Call Alert and all of our portables start to beep until they are reset (I like this one better than just an alert tone) HT1250's with a unique alert (think it is #4) at a fixed alert volume.

[pfd radio]

You could probably program a button to Call Alert member #1 on your call list - and make it a QCII single tone to make it easier for the incident commander.

On our HT1250 we use "Alert 4" for call alerts - It ramps up and down and it distinctly different from our air pack pass alarms.

[HLA]

another thing to remember is if you're already using mdc you won't be able to use it and qcII

[Andy2712]

I really would rather they just had a button they pushed and the "tone" would be broadcast across the radio. Trying to use mdc wouldn't work because of the amount of mutual aid companies that could be on the scene.

[pfd radio]

Just to clarify we use the QCII format just to generate an attention getting tone. Just a way to generate an audio tone.

Our "ALL CALL" (MDC) is a Call Alert addressed to "FFFF" which is any MDC radio on the frequency and within range.

[HLA]

no you didn't understand what I was saying, on the recieve radios, if they are set up to recieve and decode mdc, you can not decode qcII on that same channel, it's one or the other, 1250's can't do two signaling systems on one channel. and as far as the transmitting radio that's generating the tones, you're not gonna get it to work that way with one single button, you're gonna have to use the menu and from experience, it's easier to generate that with a ht1250 or ht1550 than a mobile. you might want to think more about a side tone instead of qcII

[thebigphish]

He won't have to worry about the radios decoding anything, if the onscene radios are CSQ (or equivalent) an HT/CDM pumping out a singletone as an encode, every radio on the channel (meeting the preexisting signalling systems requirements) will hear the tones as audio.


(Our local PD had to do this, as the butcher shop that put in the console couldn't program QCII in correctly, and they resorted to recoding a .wav file of the tones, and blasted them out OTA for the units - talk about poor alerting compliance! - glad i'm done with that.)

HLA, you're exactly right that the radios won't decode multiple systems, but he may not need them to be.

[pfd radio]

HLA - I thought he just wanted an attention getting "Audio Alert" tone. Not actually have it open radios (like you would ordinarily do for QCII). I have programmed a singletone on some XTS radios where the person would push the repeater access button (once again not using it for repeater access) just to generate a 1000 Hz tone. Similar to an Alert tone.

You are also correct you probably can't do what he wants with a single push of a button - on that radio.

I'm sure you could use an oscillator and send it through the aux audio as well - small box with a momentary push button. This would accomplish what he wants. You could probably use a 555 timer to to make it oscillate Hi-Lo as well.

[HLA]

ya i'd say he's looking more for a side tone. if he does use qcII, and it sets off the recieving radios, they're gonna have to push some buttons to reset it. even autoreset takes some time and they will miss whatever info is being transmitted?

[Andy2712]

The small box with a momentary push button that would oscillate hi lo is exactly what I want. How do I do that?

[thebigphish]

Buy a tone generator, wire it in an aux input in the back, and program the radio accordingly.