I will agree with your statement that the microphone pre-amp circuit
is closer to older none "Pro" Icom models and that we may have to
deal with that situation all over again.
Yes I know quite well that it is a "inexpensive" microphone but it is
the only one that has all of the control features built in that I use
while I am mobile
The interesting find that I ran into with my own unit was that when
I replaced the "stock" Icom element with a salvaged Cell phone
(Nokia) single hole element my audio went way up and it was clear and
crisp not distorted and mushy on FM (I have a normal voice, not bassy
or high pitched).
For testing purposes I installed a mini Teflon insulated socket on
the mike PC board so as to keep things nice and tidy and decided to
test the elements externally using the same voltage/current setup
that Icom has in the hand mike (got the info from the schematic).
The results indicate that some elements, I tested 5 different
electrets' that I have in the shack have built in amplifiers (3) and
the stock Icom model is not one of them nor is the R*t Shack unit.
The Salvaged Nokia element has a built in pre-amp and thus the
better higher level audio with no need to run "compression" on SSB.
I decided to build a small single stage pre-amp and match the level
to the Nokia (dead bug style and then heat shrinked) I hooked it to
a extra H-5 element and it works quite well thank you very much but
no space for the element.
At this point I see that all one needs to do is get a electret
element that has a built in high level (some elements can be adjusted
by supply voltage) and substitute the stock element to solve most of
the 7k audio hassle, or splurge the $30 and have it done by one of
the board members who first did it for his radio and now offers this