I had been getting reports that the HM-36
shipped with the IC-7200 ( IC-718, IC-7600, IC-7700, IC-7800) is low
and muffled. I checked on on the bench and the
reports are absolutely right. It is the "Chinese" HM-36 (check the
rear of your mic) that is the problem. It's better than the stock
but still isn't delivering the quality of audio that can show what
the radios are capable of. The Japanese HM-36 has better
There are a few mods out there to improve the mic,
but they still use the stock
element. None of them get you where you need to be. I use my
custom type #2 element - (the one I use in the HM-151 for the IC-7000)
- and it brings the HM-36 to life. The improvement
is significant. The frequency response opens up top and bottom.
Audio drive level is also increased by about +40%. It goes from
muffled - to clean and robust. You can then easily adjust the TX
sound to whatever you like with you rig's TX tone controls. For FM
and AM, you will have the top and bottom frequencies for great
audio. On SSB, you can dial it down for a narrower passband. Without
plenty of clean audio drive to begin with, you can't get there
The upgrade is actually
more complex than the one for the HM-151. This is because the DC
biasing resistor and audio coupler cap are incorrect as well. This
means that the resistor, the coupling cap and the element have to be
replaced. There is no room for an additional weight ballast inside
the HM-36 shell - because it already has one.
I know you have other options (on-line mods), but I can guarantee
if you use my Type #2 element, you will have much better audio.
(check my reviews :
I'm not modifying the Japanese-version HM-36
at this time.
Even though it's a more complex mod than the
HM-151, I'm keeping the price at only $39.50 plus shipping.
Insured Priority 2-3 day return shipping is $8.50, so the total is:
$48. Ship it to:
103 Georgian St.
Hot Springs, AR. 71901
Stock HM-36 - Chinese
HM-36 with AB5N Type #2 Element
I used a FT-897D as the receiver (7600 for TX). I set the stock
microphone for a S-5 signal coming in. When the element was changed,
it had enough increased drive to give a S-9+ RX signal at the same mic
level. The RX AGC then kicked in, lowering the background noise.
Rather than lower the record volume, I just left it as it was- to
show you the difference in drive. My observation is that the Type #2
element does these things:
audio drive by about 40%- More power output on SSB.
It has more clarity over the entire range - opening up the sound.
It provides a considerably more present and articulated audio.
It isn't quite as dramatic a difference as on the
IC-7000's mic - because the HM-151 on the IC-7000 is a much worse
stock performer. On the HM-36 Chinese edition, this will give you
the audio drive that can reveal what the radio's TX section is
capable of...and that is a much better signal.