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PSK 400bps G3RUH board. 74hc297? (was: CQ PSK31 on Oscar 10)

I've a stand alone 400bps PSK demodulator PCB board from G3RUH for
AO-13 and P3D type telemetry system since some years now.
This board has a couple of PLL chips in the bit clock and carrier
recovery DPLLs, 74hct297 that I can't find anywhere.

 Could someone point me to a source where could I buy these 
 PLL chips (74hct297) in small quantities, to complete the board?

Really this is a huge board (6"x8.2") with many parts, but all cheap
and easily available,(excluding the 74hct297), that could be easily
done smaller and cheaper with today's technollogy in a mixed analog
design with the digital part sintesized into a CPLD or FPGA.
Also all without to need a PC running.

 There is such design done yet? or planned?

Peter Guelzow wrote:
> The TNC-1 already had an "Modem Disconnect" connector for an external
> modem. It was to easy and after a few days I already had a complete
> hardware design ready for testing.  The modulator was very simple,
> using only very few components. For the demodulator I used the 400 Bit/s
> demodulator which was already in use for my P3 command station.

I wanted to buy a 1200bps PSK board from G3RUH when purchased the
stand alone 400bps PSK demodulator PCB and 9k6 boards, but the PCB
was no longer available.

 Please, could you provide schematics of these?

I'll like to try to make some myself, and could be that even work
on sats someday.

73's de Luis

mail: melus@esi.us.es
Ampr: eb7gwl.ampr.org (sorry shut down)
AX25: (sorry shut down)
http://www.esi.us.es/~melus/   <- Homebrewed Hardware Projects with PCBs

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