View Full Version : IC-2700/ HM-90A
07-18-2013, 04:23 PM
I purchased a IC-2700 radio and it came with the HM-90A mic (can operate wireless or wired). I am trying to work it wired I have it plugged in to the radio and mic directly. The address is set correctly, but it still doesn't communicate to the radio. PTT does not transmit and no other buttons (changing frequency, volume, squelch, ect) do not communicate to it either. Does any one have any suggestions as to what the problem is or how to figure it out? I am going to talk to some local hams and see if they have a microphone that is compatible to rule that out, but haven't been able to get a hold of them yet.
HOPEFULLY, your IC-2700H has the Infrared Recever for that microphone !!
EX-1759 Infrared receiver required for the HM-90. Discontinued
HM-90A Wireless microphone (requires EX-1759). Discontinued
07-19-2013, 05:02 PM
You can also operate wired (direct from the radio to the microphone) and that is what I am trying to do. It isn't working. I tried it last night with a different microphone and it worked, so the issue appears to be in the mic cord or microphone. Going to have the wires checked today.
This HM-90A microphone appears to use an internal rechargeable Ni-Cd or lithium cell that powers u-processor when not connected to a cable. Just like your cordless telephones at home.
Icom HM-90 microphone : schematic diagrams
ICOM AMERICA - AMATEUR RADIO EQUIPMENT SUPPORT
Icom America Inc.
2380 116th Ave NE
Bellevue, WA 98004. USA
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