I dug some more into the PC board and figured it out.

3 is Mic GND
4,5 are no connection
6 is Mic +

So to my IC756ProII it's:

Motorola RJ-45 : Icom 8 Pin Mic plug
1 : 6
2 : 5
3 : 7
6 : 1

All others are not connected.

The mic sounds great. Much richer audio than the stock hand mic, and
because of the embedded preamp My mic gain sits around 10 o'clock as
opposed to the usual 3 o'clock with the Icom HM-36.

Now to decide if I really need those up&down buttons...


Thanks Rich for the part number update!

'73
Pat, VE3PMK





Rich wrote:

1. Item Number. BMN1000A * The item BMN1000A has been
replaced with
MBMN1000C. Selecting this item will add MBMN1000C

MICROPHONE, VORTEX II
Unit of Measu 1 EA


"lg" wrote in message
news
I've tried google and yahoo but can't seem to find the pinout.

It's a desk mic with a long gooseneck and two buttons (PTT & Mon)
There's no cord, and I've got it pulled apart on the bench here and have
figured out most of the RJ-45 connector on the back. The two right and
leftmost pins (1&2, 7&8) are for the PTT and Mon respectively, and it
appears 4&5 are NC. The mic audio appears to be on 3&6, but I can't
quite decipher the polarity as there's a bit of a preamp circuit on the
board. The other puzzling thing is the fact that the ground of the PCB
(which is also common to one side of the mic element) does not come out
to the RJ-45 connector.

Anyone here have Motorola experience that can share the pinout with me?
The circuit board itself is labelled "BLN7150A C2546585"


reply here or email

Thanks!
Pat, VE3PMK