[Icom] Additional Info, Icom (HM-36) Hand Mic

[William J. Wickstrom]

"Bill I loved the info on the hand mic I still have mine and am wondering
what was the thing in there for, a spacer or what? I might take mine
apart and remove it, what do recommend? I have the OLD PRO,,,hahaha and
love it."
David S. McCallum [w7sac@juno.com]
"Hi William,
What a suprise!
Thanks for the great info on this issue. I had no explanation for the
obvious
low drive and poor frequency response of this microphone. I expected that
aside from the inconvenience of the hand-held mic, it should sound
as good as a desk mic. I'll take a look inside for a physical solution!
73,
Don Rasmussen"

Hi, David and Don:
	I recommend removing it, as I have done. It's a very simple
"surgery"---simply remove the three (3) screws that hold the case together,
carefully separate the two case halves. Inside the front case half you'll
find a steel retaining ring and a heavy steel reducer plate into which a
rubber shock-mount grommet containing the electret element itself is
pressure-fitted. Gently pull this grommet from the reducer plate (there is
no need to remove the retaining ring screws). Carefully push the element out
of the grommet using a pencil eraser end through the hole on the front side
of the grommet. Discard the "cue stick tip" and reassemble the mic in
reverse order of disassembly.
	As to your question about what function this piece of felt performs: as
near as I can figure, it is supposed to act as a "pop filter", reducing
breath and wind noise. In my experience, it reduces a lot more than that! If
you're concerned about an increase in these "explosives" after this
modification, cut a small plug of OPEN-CELL (very important!) foam of the
appropriate size and install it where the felt plug was. Be careful not to
compress this foam. To do so gives you the same problem you just tried to
alleviate.
	For anyone who cares, I am an audio engineer by profession, but operate
almost exclusively CW (even mobile!). I just love the mode! I am NOT one of
the "hi-fi on SSB" cult (c'mon, you frustrated DJs), but I do want the
outgoing audio from my station to sound as natural as the modes (and the
law) allow. I sure was surprised and disappointed to receive reports on my
new $2800.00 radio of "gosh, what's wrong with your rig?" using the HM-36!
Now that mic sounds dramatically better! Unsolicited reports like
"outstanding audio" and "what kind of mic is that?" are the norm. Don't
misconstrue-this is still a COMMUNICATIONS microphone. This modification
simply makes it a better one. Coming soon: HM-103, HM-77 and HM-88A.
	Man, I just love my Icom radios---'706mkII and Delta100H mobile, '756proII
and, '290H and '2100H in the shack (looking for a great deal on a '970H/A
;-) ). It's Icom all the way!

73 all!
William J. Wickstrom, Chief Engineer,
Surge Performance Sound.
surgesound@ameritech.net

William J. Wickstrom, W1IK,
USECA Morse Instruction Coordinator
w1ik@arrl.net

William J. Wickstrom
NNN0AHCT
Amateur Call W1IK
w1ik@arrl.net