Replacement remote mic impossible?

[KF4ZHL]

pins on Standard C5900 modular 8 pin microphone jack:

1. 13.8 V
2. Control
3. Speaker Output
4. PTT
5. Ground
6. Audio Input
7. Microprocessor Interface (Data)
8. Microprocessor Interface (Clock)


I can't seem to find ANY microphone that has the same basic specs as the Standard mic. I can change around pins, and I can even adjust voltages, but I can't make the radio and mic controls "talk" to each other if they don't use the same method to communicate.

I thought maybe Yaesu mics might work, but I can't find a description on what the control pins do. They are simply labeled SW1 and SW2.

Should I give up the dream of an operational replacement control mic for this radio?

[W9GB]

Ken -

MANY newer radios are replacing the microphone with a remote data entry/audio input device that looks like a microphone (and largely proprietary interface).

Assuming that they are still using standard analog audio and DC PTT -- then these are the ONLY relevant pins/functions !

4. PTT
5. Ground
6. Audio (MIC) Input

Unless you can find a schematic for the original Standard microphone -- you will have to reverse engineer it. That will require a VOM and dis-assembly of the Standard microphone.

w9gb

[KF4ZHL]

Ken -

MANY newer radios are replacing the microphone with a remote data entry/audio input device that looks like a microphone (and largely proprietary interface).

Assuming that they are still using standard analog audio and DC PTT -- then these are the ONLY relevant pins/functions !

4. PTT
5. Ground
6. Audio (MIC) Input

Unless you can find a schematic for the original Standard microphone -- you will have to reverse engineer it. That will require a VOM and dis-assembly of the Standard microphone.

w9gb

Ah, yes. Those were the words I knew I was going to hear. "Proprietary interface" means that I may be lucky enough to find a mic with a built in DTMF tone generator that I can get to run on 13.8 volts. Oh well. Thanks for the help sir.

[W9GB]

Those were the words I knew I was going to hear.
Same message has been repeated at Dayton and countless inquiries at Heil Sound and amateur radio dealers.

"Proprietary interface" means that I may be lucky enough to find a mic with a built in DTMF tone generator that I can get to run on 13.8 volts.
There have been NO industry agreed standards for microphones (e.g. wiring, wire color, element usage) -- outside of professional audio adopting the 3-pin XLR connector a few years ago.

Nothing preventing you from using your electronics knowledge and ability to use test equipment to decode the interace, build your solution, and then use it --- amateur radio is permitted this luxury.

Audio/microphone market has been a competitive capitalist market -- the personal computer marketplace and telecom industry were dominated by virtual monopoly companies (IBM, AT&T) until 1980s. Some of their product standards became indusry standrds (de facto), while many standards were developed in late 1980s and 1990s -- for the plug-n-play consumer enviornment that exists today.

7. Microprocessor Interface (Data)
8. Microprocessor Interface (Clock)
When I saw these two lines on the connector -- I immediately think of the IBM PS/2 6-pin miniDIN keyboard interface (whcih has those same lines) --
BUT the 13.8 VDC is not at the traditional +5 TTL/CMOS supply voltage.

I also ask the deisgn question -- did the original designer "buffer" these 2 uProcessor lines --
so that a customer mistake at the connector (or third party devices) does not destroy the radio's uProcessor?

I thought maybe Yaesu mics might work, but I can't find a description on what the control pins do. They are simply labeled SW1 and SW2.
Should I give up the dream of an operational replacement control mic for this radio?
BTW -- Vertex/Standard merged over 10 years ago and produces the Yaesu radios.
Have you even asked Yaesu / Vertex USA for product support ? a schematic ?

You need to work on the electronics schematic level ... I learned to read schematics (1970-1972) in high school ... before I became a radio amateur
and have kept my knowledge current with changes in the electronics technology (from vacuum tubes to ICs) over the past 40 years.

w9gb