[ICOM] Mic wiring required HM-14

[Gary Fiber]

Reed,

Going from memory and its been a while.

You can verify the Up / Down wire by placing an ohmmeter between it and the 
ground wire. with the PTT not depressed you should have a short when the up 
button is depressed and 470 ohms resistance when the down button is 
depressed. PTT is easy again use your ohmmeter between the Red and Green 
leads there should be a short when you depress the PTT button and an open 
when you release it. White is conventional for mic audio input on Icom. I 
seem to remember the DTMF chip got is voltage from Pin 1 on the HM-14. Yes 
Pin 2 on the radio also has 8 Volts on it and it is used to power 
amplifiers like in the SM-8 but I don't remember Icom using it in the HM-14.

If I am wrong others here will correct me.

White - Pin 1 Mic Audio
Black - Pin 3 Freq UP / Down
Red    - Pin 5 PTT
Green - Pin 6 Ground
Shield - Pin 7 Mic audio ground

Pins 2 ( 8 volts ), 4 ( squelch Switch ) ,and 8 ( Receiver Audio ) are 
empty on the HM-14 mic connector.

Gary K8IZ


>Buddy of mine dropped of an HM-14 mic that as he said on the phone,
>just needs a wire soldered.  HA !  What an understatement. Somehow
>he was able to pull all the wires off the inside of the 8 pin connector. Can
>anyone direct me to a site that might show the wiring for this mic ?  I have
>tried the old google trick, but can't find anything. He did bring the manual
>for the IC-228H radio, but it doesn't show the mic wiring, only the wiring
>in the radio. It's not an easy job of following the wires in the actual mic
>case,
>believe me, I have been trying.
>
>What I really need to know is what colour wire goes to what pin number.
>
>Thanks in advance for any help.
>
>7 3
>Reed

Gary Fiber K8IZ
GROL PG-19-6691
Washington State Resident