ADF Qustion
I have a question that I can't seem to get a definitive, satisfactory, answer to.
My Cessna 150 is equipped with a Bendix ADF, which is deadly accurate within, let's say, 3 NM.
(I know this because occasionally I'll deliberately concentrate on keeping the ADF needle pointed absolutely on the nose, observe a "station passage", (as it were) and then afterwards I'll review my GPS track and scale it off. I've never been more that 200' off, even at 4500 msl, according to Garmin.)
Outside of that range, let's say, 10 NM, the heading "to" difference between my ADF and my Garmin GPS will vary by as much as 20°.
So, my question is: Is that common? Is it an acceptable variation? Does my ADF need calibration? Or is this the wrong forum to post this question in?
Thanks,
Buzzerd