[time-nuts] Z3801 misbehaving

John Green wpxs472 at gmail.com
Mon Jan 25 20:54:20 EST 2016


After running continuously for about 3 years at work, I stored my Z3801 for
a little over a year. I recently took it out of storage and when I hooked
it up, all I get is a power on light. The front panel LEDs light in
sequence and the 6 inside blink red once and then the last one blinks
continuously as always. Thing is, it never locks on GPS. I even left it on
over night. When run on 27 volts, it starts out at about 1.1 amps, then
after about 10 minutes, goes up to 1.26 amps. Then, after about 30 more
minutes, it settles down to .88 amps and stays there. The OCXO gets warm. I
haven't checked for 10 MHz out, but I am pretty sure it is there. I hooked
it up to my netbook but I get no response from it at all. I am using one of
those USB to serial devices and it used to work. I am looking for a PC with
a real serial port to try. I know the antenna is good. It works with one of
those Symmetricom GPSDO cards.  Having heard about the evils of tantalum
capacitors for years, I replaced them all except for those on the GPS
receiver board itself. All the test points that call out a voltage read
correctly. I'm thinking of trying a new GPS board next. I have had this
thing a long time and it has always just worked. Any ideas what the problem
is?



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