[Icom] Help for ICOM HM-12 Microphone

Wed, 27 Nov 2002 14:15:18 -0500

The earlier ICOM rigs didn't have many lows.  The TX audio bandwidth is
2.4k.  In some of the rigs there is a switch to change it from 2.4 to
2.7, I think.  

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of [email protected]
Sent: Wednesday, November 27, 2002 12:41 PM
To: [email protected]
Subject: RE: [Icom] Help for ICOM HM-12 Microphone

I took it out and the output doubled, but it is still too weak at the
lower
frequencys.  I can get full modulation only with a shrill whistle.  With
voice it is only about 25% modulation.

Original Message:
-----------------
From: Brad Humphries [email protected]
Date: Tue, 26 Nov 2002 16:36:02 -0500
To: [email protected]
Subject: RE: [Icom] Help for ICOM HM-12 Microphone

You really don't need the .047 cap. Since you are using an electret.
Take that out and your output will jump!

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Ken Meyer
Sent: Tuesday, November 26, 2002 4:14 PM
To: [email protected]
Subject: Re: [Icom] Help for ICOM HM-12 Microphone

I have a brand new Icom HM-12 mic, 
Still in the plastic wrap, $45.00 shipped
to your door via UPS ground. 
73   Ken     [email protected] 

----- Original Message ----- 
From: <[email protected]>
To: <[email protected]>
Sent: Tuesday, November 26, 2002 2:04 PM
Subject: [Icom] Help for ICOM HM-12 Microphone

I pulled the microphone apart and discovered what appears to be an
electret
element so I tried putting in an electret from Radio Shack when I found
the
red wire had 8.0 Volts coming through a 1K resistor it seemed to match
the
schematic for an electret mike.  After puting it back together using the
RS
element and a .047 cap in series to the audio line I had modulation once
again, so I think I am on the right track, but it is very low output.

So I need some advice or I still need a HM-12 mobile mike for the ICOM
725

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Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/

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Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/

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Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/