[time-nuts] Rapco (Pendulum) 2804B - Troubleshooting . . . (III)

[Ulf Kylenfall]

After replacing the GPS-Antenna, The unit reports the whole sky full
of satellites, most of them with good S/N values. The unit does not
reset itself anymore. Furthermore, after some time, the display
indicates "Frequency Lock" - But it is a false indication.
It is nowhere near.

The DAC output value starts at a low value, where the OCXO is 1 or 2 Hz
below 10,000,000 Hz. Then slowly rises till it rushes all way up to 99,9%
which is +2 Hz above 10,000,000 where it stays. No indication of the
unit ever trying to correct this latch-up situation. Even in this
state, the Front panel LED indicates that the unit is operating normally.
There are no alarms, No error flags.

Not having a service manual and no information about the GAIN-setting
parameter, I have decided to spend no more time with it for now.

Ulf Kylenfall