RE: sonogram values  (1725)Reply RE: sonogram values  (1725)Reply tdigitalmusic
Sep 08
Hi John,

I'm sorry, I don't know anything about VOR signals.
Perhaps try starting a new conversation topic, and other members of this group may be able to help.

Good luck,

Thorsten
_____________________________
Re: VOR decoding

Hi John,

here's my first attempt on a VOR phase measurement:

http://dl.dropboxusercontent.com/u/26404526/SDRsharp_VOR/SDRsharp_VOR.jpg
http://dl.dropboxusercontent.com/u/26404526/SDRsharp_VOR/SDRsharp_VOR.usr

I have used an RTL-SDR stick and a dipole to receive my strongest local VOR (Erlangen 114.9 MHz, about 25 km away so SNR may a bit marginal). Demodulation in SDR# software is set to USB with 16 kHz bandwidth, placing the 30 Hz AM carrier at 1 kHz and the upper 9960 Hz FM-modulated subcarrier at 10.96 kHz. Audio output occurs at 32 kS/s and is fed to SpecLab through Virtual Audio Cable software. SpecLab runs an AM demodulator on the left channel and an FM demodulator on the right. The phase between the two 30 Hz outputs is measured by the colour-DF spectrogram function which then outputs azimuth directly. I have not checked whether the RDF measurement should be clockwise or counterclockwise, and whether there should be an angular offset. Note that this technique will probably only work for standard VOR's with a pure carrier, and would have to be modified for a Doppler-type D-VOR.


BTW I'm having a hard time reading the new Yahoo "neo" website format. Seems much slower than before, and on a small screen, between all the title bars and ads there's hardly any room left for contents.


Best 73,

Markus (DF6NM)
http://df6nm.de


Re: [SpectrumLabUsers] VOR decoding  (1723)Reply 
Jean Marie Polard
Sep 06

Hello to you all,

I wonder if one can use SL to decode the phase difference of a VOR 
signal versus our local stn and give the angle or a data which can help 
us to deduct an angle ?

any trick ?

best regards

John F5VLB