[rescue] Radio DF equipment (was Ham radio license question)

G W Adkins rescue at sunhelp.org
Wed Jun 13 09:59:32 CDT 2001

> So now you have two points and can draw a line on which the noise source
> lies.  I forget exactly how the ramsey kit determines which doppler null
> is the one that points toward the target...I'd have to go dig up the books
> from the basement...but I remember it having something to do with audio
> phasing.
> Now...when you induce a doppler shift on a signal and attempt to decode it
> through an FM detector, the doppler shift induces a tone in the audio.
> that tone is indicative of the doppler shift amount.  If you know that and
> your angular position in the described circle, you can plot your nulls on
> the circle and then draw your line.
wouldn't it be simpler to plot the peak and trough and add/subtract 90
degrees from the peak (depending on the rotation)?

More information about the rescue mailing list