skyav8r wrote:

Howdy,
I have an Aeromech 8140B20 encoding altimeter with a KT76 transponder.
Mode C is intermittent with ATC. Is it more than likely this is an
altimeter problem or transponder problem? Sometimes when it is not
reporting, i cycle the transponder off then back on and it starts
reporting again. Thanks in advance,
Brian
Also, sould an aeromech and aerosonic encoding transponder interchange
as far as the connections are concerned?




Old encoders do go intermittent. I finally replaced mine to cure the
problem. But mine would not always come back alive upon a recycle, or it
would report all sorts of weird altitudes to ATC.

I bought another transponder on e-bay to try a "swap test". When swapped
the problem persisted. You might try swapping with an airport buddy who
has the same unit to try to cheaply isolate the problem. Since these
units slide out of their trays, the swap is usually easy.

If it is the encoder, you of course have to replace or overhaul the
altimeter, which I believe may be a bit more costly.

Good Luck,
Mike