[time-nuts] Looking for info/manuals for Absolute Time 150 and 300 GPS Receivers

[Stan]

I just acquired one of each of these receivers but with no manuals,
instructions, or any other information whatsoever. They look to be mid-90's
vintage, standard rack width, with RS-232 for control and monitoring, and a
few selected standard frequency outputs. Any information on their use,
service, troubleshooting, etc. greatly appreciated!

Thanks,
Stan