"Orval Fairbairn" wrote in message
news
In article ,
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?

Check for oil/dirt buildup on the TXP antenna. THere is usually a lot of
carbon in that stuff -- it can short out the antenna on Xmt.

This is the most common problem and should always be checked first. The
radar sensor interrogates Mode3 2-3 more times for every ModeC
interrogation. So poor reception/transmission will show up on ModeC first.

I clean my antenna at every oil change, but my plane throws off almost no
oil. The more oil your plane goes through, the more often you should clean
the antenna.