Hi Bob,
On 04/01/2013 10:06 PM, Bob Quenelle wrote:
I’ve been running an FE-5680 for maybe a total of 50 hours over the last
several months. I found that an offset setting of 180 made it track GPS and
(previously-set) LPRO-101 10 MHz signals. Even with power cycling, after about
1/2 hour, with an offset setting of 180 the FE-5680 was stable. The last time
I turned on the FE-5680, it drifted with a setting of 180 and needed a new
setting of –415 to track the other signals. That’s a change of 595 counts and
with a resolution of 6.8 uHz per count, a frequency change of 4 mHz (0.004 Hz)
and 0.4 ppb. Operation at the new setting is stable for now. The lock signal
indicates lock and the power supply voltage is still 15V. I haven’t checked
lamp voltage or VCXO voltage as that requires opening the case.
Before I start poking around, thought I’d ask if anyone has seen a similar
symptom. Time to open it up?
How long have it been turned on since last power-up?
Let it sit for a day at least.
I've found that it is easy to be in too much hurry to judge the
situation and trim things efter power-up. The crystal oscillator just
doesn't get the time to settle in.
When triming up caesiums, I did this mistake myself, altered my ways and
got a much better result.
Cheers,
Magnus
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
