The VOR signal out of the receiver is a 9960Hz sine wave that is AM
modulated at 30Hz and FM modulated at 30Hz. The phase difference
between the AM and FM signals is the bearing to the station.

Outside of the standard service volume of a VOR, this signal starts to
get quite noisy. This makes domodulating the AM and FM components
more difficult as the signal to noise ratio degrades. The quality of
the filtering of the 30Hz and 9960Hz bandpass filters (or equivalent
digital bandpass filters in a DSP) determines how far out you can
accurately receive the station. Apparently the SL30 does a better job
of filtering out the noise than the GNS430.

Dean

Maik wrote in message ...
Hi!

I have a SL30 and a GNS 430 in my plane. They use the same antenna via a
splitter.
When I dial in the same VOR in both units the SL30 catches up the
radials always between 20 and 50 nautical miles earlier than the GNS
430! (Altitude about 3000 ft, flat area)

Is this normal?
What is your experience?
How far away do you have a reception of a VOR with your GNS 430?

Fly safe!
Maik