This page is dedicated to gathering info on DTMF microphones that are used with Motorola's mobile radios. You will find that there are only a few designs that they use, and most of the microphones can be used on other radios, with the correct cable attached.

HMN1010, 1011, 1024, 1014 1022, 1032, 1018, 1019, 1020, 1033, 1034 1021, 1023, 1025, 1026 DTMF Microphones

The manual part number that covers all these microphones is 68P81114E07.

Jumper Settings

• Placing JU3 in Position A defeats limited tone operation. In Position A, tone duration lasts as long as touch-pad key is depressed. In Position B, tone duration is controlled by timer U3
• Placing JU4 in position C selects a PTT hold time of 1.4 seconds. Placing JU4 in Position D selects a PTT hold time of 2.5 seconds
• Placing JU5 in Position F selects a * , #, time of .5 seconds. Placing JU5 in Position G selects a time of 1.25 seconds
• Removing JU2 will inhibit any tome generation if more than one keypad button is depressed
• The small variable pot R32 controls the Dev output of the microphone. A special tunning tool 66-84974L01 is required

You will also find that the above information holds true for the MCX1000 DTMF microphone (VLN1017A) and for the Maxtrac Backlit DTMF Microphone (TDN8310A).

VLN1017A DTMF Microphone

If you have a VLN1017A DTMF microphone from a MCX1000 and are looking for a schematic for it... look no further. It is available in the service manual, or, you can look at Tone/Logic Board and the Microphone/Beeper Board schematics. This board layout will make locating the proper jumpers a bit easier. Note that if you have a Maxtrac TDN8310A DTMF microphone, it uses the same schematics, with slightly different part numbers.

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