In article ,
"log" wrote:

On a recent trip, ATC said my transponder was now showing my altitude. Is it
the altimeter or the transponder or the encoder?
BED



It could be:

1.The transponder is scrambling the Mode C info from the encoder.

2. The encoder id malfunctioning.

3. The wiring harness from the encoder to TXP has a bad soldeer
connection. I take it the problem is intermittent?

4. You were in an area of marginal radar coverage and flew into an area
of better coverage.