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I have GM300 VHF radios but I want them to be DTMF with the keypad, if I get some mics with the keypads will this work or have the radios got to be a different model

thanks lance

lancerice wrote:I have GM300 VHF radios but I want them to be DTMF with the keypad, if I get some mics with the keypads will this work or have the radios got to be a different model

There's quite a bit of info here http://www.repeater-builder.com/motorol ... stuff.html on DTMF mics for the GM300.

The AARMN4026 DTMF mic for the newer Pro series won't work with the older Radius/Maxtrac radios. That mic uses pins 9 and 10 of the mic connector for the DTMF control; tones are actually generated in the radio if memory serves. IIRC, the older mics are 8 pin as is the radio's mic connector and generate DTMF in the mic and send it down mic hi to the radio.

This is the mic you would need for a GM300. The black ones meant for a CDM will work ust as a mic, but as stated, will not create DTMF tones

Separate DTMF encoders such as made by Midian are another option you could look into. These could be connected to the ACC connector.

I have the mic 601 has pictured and can confirm it works on a GM300. I don't use it because it is much heavier than the average mic. I haven't tried an MCS control mic on them but that "might" be an option as well?

601 wrote:This is the mic you would need for a GM300. The black ones meant for a CDM will work ust as a mic, but as stated, will not create DTMF tones

That mic on my GMs was creating a tone last I checked. If need be I can try and find it in the Moto $hit box here and hook it to the M120 VHF I have on the desk for testing.

thanks people for this, what I am looking to do is use the keypad to call radios but only the radios that I want to call, not all of them

would this be what I need, I am also going through a repeater

thanks lance

lancerice wrote:thanks people for this, what I am looking to do is use the keypad to call radios but only the radios that I want to call, not all of them

would this be what I need, I am also going through a repeater

thanks lance

That will depend on how the receiving radios are set up to decode and alert to DTMF. Each should have a unique ID, and if there are group or all calls, they would each be programmed for that as well. You should be provided with a list of these ID's.

If the repeater is DTMF controlled, you'll need to know that and have the codes, too.

I know these radios are capable of MDC (which this mic would be useless for) but to have DTMF calling I think you would need an extra addon somewhere as I don't believe it is built in.

GM300's, MaxTrac's, etc as stock do not decode DTMF. There was a DTMF decoder option board available for them when the radios were still in production, but out of the box, they don't support DTMF decode.

Taking a quick look at the GM300 user manual, it looks like you can do selective call from the front panel, but only the 16 channel models, can anyone confirm that? I've set them up for 2 tone alerting using an encoder console, never messed with the call lists though.

Lance, are your radios 8 or 16 channel models?

tsunami_australia wrote:I know these radios are capable of MDC (which this mic would be useless for) but to have DTMF calling I think you would need an extra addon somewhere as I don't believe it is built in.

I'm pretty sure that the OP was asking if he could add a DTMF mic so that he could transmit DTMF. Several of us already explained that he could do that and pointed out some mics that he could use and one that he could not use.

d119 wrote:GM300's, MaxTrac's, etc as stock do not decode DTMF. There was a DTMF decoder option board available for them when the radios were still in production, but out of the box, they don't support DTMF decode.

If I understood the OP correctly, he was only asking if he could add a DTMF mic to his GM300 so that he could transmit codes to other radios which presumably would be able to decode the DTMF. He didn't say anything about decoding DTMF with his radio.

jackhackett wrote:Taking a quick look at the GM300 user manual, it looks like you can do selective call from the front panel, but only the 16 channel models, can anyone confirm that? I've set them up for 2 tone alerting using an encoder console, never messed with the call lists though.

Lance, are your radios 8 or 16 channel models?

My 16ch UHF T band has MDC enabled. I meant to get it working with my Jedis but never got around to it. I have sent a few calls and confirm it is MDC call on PTT off'ing.

And yes the OP was asking about SENDING DTMF by what I read thus my original answer of yes that mic did work with my Radius'.

so for me to send DTMF I can buy these mics and that will send the DTMF to the other radios, But do all the radio need to be fitted with a DTMF decoder aswell?

Thanks Lance

lancerice wrote:so for me to send DTMF I can buy these mics and that will send the DTMF to the other radios, But do all the radio need to be fitted with a DTMF decoder aswell?

Thanks Lance

Yep. Gotta be something on the other end for it to be practical. Pitch - catch.

is there a certain type of decoder, for gm300's and gm350's

Lance, how many radios are you planning to do this on?

I have one repeater (2 x gm300's), 2 visar's and 7 gm300's and gm350's

If you are looking at a selcall type setup then look at the MDC1200 calling in the GM300 or upgrade to some MCS2000's and use the paging function. MCS2000's are not worth much any more (even going under $100 in Australia from time to time) which is surprising given they are still great radios but I guess the lowered prices of P25/MotoTRBBO gear has forced a reduction.

Those DTMF mics haven't been made in years, so you'd be hunting down used ones. The decoders for GM300s were rare even when they did make them, so you'd have to get aftermarket decoders.