[time-nuts] Z3801 misbehaving

[John Green]

After a couple of days of GPS lock, it went into holdover. I briefly
powered it down and it attained lock again in about 15 minutes. But, a
while later, it was back in holdover. I finally coaxed that Sager laptop
into working and after connecting to it with genuine RS232, I still can't
communicate with it. I get zip with Satstat. And, it isn't locking again
either. So, while it will achieve GPS lock, it doesn't seem to want to stay
locked. And, there is that troubling lack of communication. I am
considering trying a different GPS receiver module. I understand that
probably isn't smart unless I try one similar to the one in it. I
understand that the internal processor talks to the GPS module and anything
with a different command set will cause it to think the GPS has gone bad.
At this point, it looks like my options are limited to buying a new, used
one off eBay for $500, or going to the Thunderbolt, which I don't trust. I
have an old desktop PC I am going to try just in case the laptop RS232
voltages weren't up to snuff. And, I am going to try a different cable,
just in case. It probably wouldn't hurt to exercise the RS232 jumpers
either. Anything else I should try?