"tony roberts" wrote in message
...
Hi
Today I was flying north and my ADF was tuned to an NDB.
The needle pointed at 330 degrees (or 11 O'clock) until I reached the
NDB, and then it swung until it pointed behind.
I dialed up the next NDB and it pointed at 330 again until passage.
And I dialed up another NDB - same indication - all of them wrong.
On the return trip - same indications.
It seems logical that the nav, ADF head and antenna are working because
I get a reading on station passage, but other than that, if I am tuned
to an NDB anywhere ahead of the aircraft the needle points at 11
O'clock.
Any ideas?

Thanks

Tony
--

Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument
Cessna 172H C-GICE

I had a remarkably similar problem with an old Bendix unit.
It turned out to be a short inside a connector, grounding one point of the
loop aerial. (The connector had been put together with no washer under one
of the screws holding the body and the slight extra projection had brought
the screw in contact with a sleeved soldered terminal pin and over the years
it had rubbed its way through the sleeve until it shorted!)
I suggest you carefully check everything on the loop antenna circuitry
outside the unit before sending it off for checking.
Mike