[arm-allstar] radioless node dtmf

Jay Urish jay at unixwolf.net
Tue Mar 5 23:39:24 EST 2019


Doug,

Have you ever looked at the motorola mics? They do encode DTMF.

https://www.ebay.com/itm/Microphone-AARMN4026B-DTMF-for-Motorola-Radio-CDM1250-CDM1550-CDM1550LS-CDM750/292196846880?hash=item44084a0d20:g:8wsAAOSwdOlcXY~L



On 3/5/19 8:55 PM, "Doug Crompton via ARM-allstar" wrote:
> We are about to release our complete radio-less node and in a production
> setting finding an inexpensive  DTMF mic that has real DTMF out and works
> well is almost impossible. The clones are often junk. We started off with
> Alinco mics and the ones offered on the Internet are Chinese clones and
> unreliable using DTMF. We ended up using a Yaesu mic and an Arduino to
> decode the voltage matrix from the mic and create DTMF tones. It works very
> well but is not something the average user would want to do.
>
> If you are building your own on a "onesey" basis you should be able to find
> a mic - Kenwood, Alinco, etc. that works. For a powered mic you need 5V to
> the mic.  I know some say 8V but all you need is 5V and that is all you are
> going to get over USB anyway. See the pin out for your particular mic. Keep
> in mind that many mics do NOT encode DTMF.  Yaesu and icom especially. They
> either send voltage levels or a data stream to the radio and the DTMF is
> created there. So not all mics will work for the DTMF audio directly out
> which you need. Levels are very important for DTMF. Go into the Asterisk
> client and observe the keys being decoded as you push them. They obviously
> should all work. In some cases you may need to open the mic and set the
> DTMF level internally if there is a pot to do that.
>
>
> *73 Doug*
>
> *WA3DSP*
>
> *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
>
>
> On Tue, Mar 5, 2019 at 3:00 PM "Alan Matthews via ARM-allstar" <
> arm-allstar at hamvoip.org> wrote:
>
>> hi group
>>
>> a bit of a dumb question, but I'll ask anyway.
>>
>> I have just finished a radioless allstar node, is there anyway to use DTMF
>> tones for linking. I'm using my icom mike from my 5100. The only way of
>> connecting as far as I can tell is via allmon.
>>
>> thanks Alan
>>
>>
>>
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