KLN-89B GPS xponder compatibility

I have installed a KLN-89B installed but the altitude comming from the xponder
is not working. The xponder is an old Narco AT50. I wonder if other pilots have
another model of xponder installed that actually interfaces with the GPS.


I thought the altitude information would come from the encoder or serializer.
Get a sandia aerospace SA35 encoder serializer (encoder with 2 rs-232 ports,
altitude information in 10' increments).

I think another possibility is that you might need to look at the wiring
diagram of the install, what was connected and how. A KLN89b is an OK gps
navigator but not a great one. I don't know who did the installation but
perhaps the avionics shop has the work order and that would explain what was
supposed to be done.

Best situation would be the Garmin GTX327 transponder which will accept the
serializer input and display the pressure altimeter with 10' increments.


paul k. sanchez, cfii-mei
on eagles’ wings
2011 south perimeter road, suite g
fort lauderdale, florida 33309-7135
305-389-1742 wireless
954-776-0527 fax
954-965-8329 home/fax