Sorry for the bandwidth, but I thought this information might be useful to 
archive for the next person that goes searching for information on the 
Spectracom 8171A clock without luck.

I spent a bit of time looking at the circuit and old data books list night, and 
got my unit up and running with the 8164.

As it turns out, the 15 pin Molex interconnect _IS_ a straight through 
connection to an 8164 type receiver. There are some oddities that throw off the 
casual observer - like only connecting to the inverting side of an RS-422 
driver, but otherwise it's fairly straight forward.

For those interested in trying to connect one of these to some other type of 
receiver, I'll give a brief signal description;

Pin     Function
4       Phase Lock - TTL active high indication the receiver is locked to WWVB
7       Time Code - TTL high when WWVB is at full power, low when WWVB is -10 db
9       Major Alarm - half an RS-422 signal - logic 1 when there's a fault
12      10 MHz standard - inverting half of RS-422 buffered 10 MHz from the 
xtal standard
13      10 MHz phased locked to WWVB - this is the noisy 10 MHz that's locked 
to the 60 KHz broadcast
4,6,10,14 and 15 are all grounds.

It's unknown how the phase locked WWVB 10 MHz is used relative to the xtal 
standard 10 MHz, but there's a family of counter/timer devices in there for the 
CPUs; they may do something algorithmically with the differing clock sources. 
There's external 1 MHz clock backup input on the back panel as well as an 
internal PCB footprint for a TCXO. Must have been a bunch of options for this 
beast.

Hope that's a help to the next poor soul that needs some data on this device, 
and again sorry for the list bandwidth.

-Carl





_______________________________________________
time-nuts mailing list
[email protected]
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

Reply via email to