A Question about homing on an FM signal

[JLX]

I understand how to put the FM radio to HOMING mode, set the correct frequency and then use the course deviation indicator to point towards (or away from!) a FM homing signal.

 

However, as the course deviation indicator only shows whether the signal is on the left or right side of the helicopter, it only helps get you on a line between you and the source signal. However, it doesn't indicate which direction on that line you need to fly to get there!

 

In other words, you could be flying directly away from the source and the indicator would still be lined up in the center just as if you were flying directly towards it! In the tests I've done (fly towards the signal then do a 180 and fly away from it) the indicator readings are identical.

 

My question is this: Is there a way differentiate whether you're flying towards or away from an FM homing signal using instrumentation?

 

I hope I missing something really simple here because otherwise it's pretty ambiguous and could leave you flying in the wrong direction half the time.

 

 

EDIT: Nevermind. I had a brain fart.

 

Of course the needle will read the same if you're going *exactly* away from (rather than towards) the source. But, if you move off track even a bit to check, the needle will swing in the opposite direction if you're flying away from the source.

 

Sometimes you can't see the forest for the trees...

Edited February 17, 2015 by JLX
Realized the answer myself. Doh!

[sondo214]

I beleive that's the only way to know. Deviate a bit and see how the needle behaves.