tony roberts wrote:

To respond to the questions that were in some responses,
if a fly a 360 the needle tracks the NDB if I am near it, but not if I
am several miles away.

I had some similar problems with the Narco ADF 841. It wouldn't lock onto
anything more than a few miles away until the radio had been on for an hour
or so. I sent it in for repair, the shop tested it and replaced two
capacitors, and now it works perfectly.

A one-hour bench-test of your ADF at a good avionics shop is probably the
cheapest place to start -- just yank it out yourself and mail or drive it
in. You're right that the problem could be the antenna or connections, but
it will take longer to test those (and most shops don't even have proper
equipment for ramp-testing an ADF antenna and cables the way they can
ramp-test a VOR antenna and cables), so you might as well rule out the radio
first: besides, you won't have to ground your plane while the radio's being
tested, unless you need it for a specific IFR approach.


All the best,


David