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 <[email protected]> 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 <[email protected]> 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 <[email protected]> > 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 -- [email protected] > >> 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 -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
