🚀 go-pugleaf

I have an aviation headset (Telex) with a dynamic microphone element that is
known to be good.  That is, I wire it to my mic input on my tape deck and get
good stuff.

The problem is that aviation radios and intercomms are back in the stone age
of carbon microphones and aviation headsets must have a level and impedence
converter to make the dynamic (in some cases, electret condenser) microphone
look like the big old carbon hand-held units.

I have adequate room in one of the earcups for a small circuit board - there
was one there for this purpose at one time, but it is now gone (long story).

I believe that there is nom. 9v across the mic leads, supplied by the airplane
intercomm.

Can somebody help me out with a simple pre-amp design?  I have assembled
electronics and had a couple analog electronics courses in college, but I don't
even have my books any more.

Thanks in advance,

-- jdm

-- 
In real life:  John D. Miller, Graphic Software Systems (GSS),    Beaverton, OR
...!{tektronix!verdix}!sequent!gssc!jdm                          (503) 641-2200
          ~~~~~~~~~~~~~  Pilots do it in three-space ~~~~~~~~~~~~~~