[ICOM] IC-756 Hand Mic Problem

[Rolly (W7DGX) & Sandra Goodspeed]

The HN=36 does not have a battery.  It gets the required microphone voltage 
of the 8 volt regulate supply in the transceiver.

Rolly W7DGX


----- Original Message ----- 
From: "David J. Ring, Jr." <n1ea at arrl.net>
To: "icom Reflector" <icom at mailman.qth.net>
Sent: Friday, May 18, 2007 9:48 PM
Subject: Re: [ICOM] IC-756 Hand Mic Problem


> Does the ICOM hand microphone(s) use a built-in battery?  Or do they
> have a adjustment for audio level (as does the ICOM desk microphone).
> The battery is used for an audio amplifier in the desk microphone.  I
> don't know why ICOM didn't use the voltage that goes to the microphone
> to power the electret condenser element though but perhaps it was to
> avoid r.f. modulation of the audio pre-amplifier in the base (?).
>
> My suspicions would be that the voltage to the ICOM hand (mobile)
> microphones was missing - but I believe the Heil microphone also gets
> its power from the ICOM transciever - which leaves a problem with else
> - wiring or batteries.
>
> I'd suspect a battery problem (if indeed the mobile microphone has a
> battery) or less likely a wire fault (highly unlikely since you used
> two microphones), an audio level adjustment at the microphone (again
> highly unlikely because of two microphones tried), or a fault in the
> transciever power feed for the microphone - but that would assume that
> the Heil had a battery to send the higher level (than a dynamic
> microphone) to the transciever.
>
> Good mystery!
>
> 73
>
> David N1EA
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