Paul, Did you move the frequency up by driving it with a function generator or by using a 4.56 or 9.12 MHz crystal? I'm thinking that maybe the quadrature phase lock is accomplished by an internal varacter or some other mechanism for 'pulling' the on-chip oscillator. That wouldn't work if you were injecting the clock Dale
Sent from my iPhone On Oct 21, 2012, at 11:08 PM, paul swed <paulsw...@gmail.com> wrote: > Jameco had them on sale for 20 cents each so I purchased some. > Moved the clock up frequency for 60 Khz and injected the 60Khz BPSK. (I > built a simulator) It did not track and in general produced noise. I > understand you can use 2 frequencies to drive it and I tried both from > synth gens. > I was looking at the RDS decoders and the data seemed to be differential. > Set it aside at that point. I am curious as to why it did not work. Like > everyone here would be great if it worked.... > Regards > Paul > WB8TSL > > On Sun, Oct 21, 2012 at 10:55 PM, Dale J. Robertson <d...@nap-us.com> wrote: > >> Paul, >> I'm trying to understand your reference to 'differential BPSK' all the >> RDS references I've looked at indicate a 180 degree phase shift just like >> WWVB. I'm thinking that differential and antipodal are just different words >> for the same thing >> Regards, >> Dale >> >> Sent from my iPhone >> >> On Oct 21, 2012, at 10:03 PM, paul swed <paulsw...@gmail.com> wrote: >> >>> Because it use differential BPSK. I have a number of them and was trying >>> it. There is a test pin that might make it useful. >>> Regards >>> Paul >>> WB8TSL >>> >>> On Sun, Oct 21, 2012 at 9:14 PM, Dale J. Robertson <d...@nap-us.com> >> wrote: >>> >>>> While looking for other stuff I came across the data sheet for the NXP >>>> Semi SAA6579. >>>> The chip is a purpose built demodulator for RDS (which utilises a 57 KHz >>>> ABPSK subcarrier on FM broadcast that is) used for traffic, song info >> etc. >>>> This chip has an anti-aliasing front end low pass filter and an 8th >> order >>>> bandpass filter followed by a costas loop and provides a phase >> synchronous >>>> regenerated carrier. What's interesting is that the switched cap >> bandpass >>>> filter and the synchronous detector are both driven by clocks derived >> from >>>> a local crystal oscillator which is spec'd at 4.332 or 8.664 MHz (76 or >> 152 >>>> X carrier chosen by a mode select pin) I'm thinking it should be >> possible >>>> to use a 4.56 or 9.12 MHz crystal or external clock to use this chip >> as-is >>>> on 60 KHz. >>>> Have a look at the data sheet and tell me why I'm full of it. >>>> Jameco is closing out these chips in DIP-16 at a nickel apiece, >>>> $3.00/hundred. >>>> >>>> Dale NV8U >>>> >>>> >>>> ______________________________**_________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/** >>>> mailman/listinfo/time-nuts< >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >>>> and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.