On Fri, Apr 12, 2013 at 11:48:47AM -0700, Burt I. Weiner wrote: > Sorry for the delay in posting this update. Things have been hectic, > and then there was NAB. > > Here's what I've discovered: The receiver started working after > about 6 hours of just sitting. However, the 9390's internal Vectron > oscillator was quite a ways off frequency and did not want to lock > after trying to stabilize all night. I had to tweak the adjustment > screw quite a ways and then, after a while, it locked. Prior to this > episode the oscillator had been sitting at only a few E-12. I > suspect that this oscillator has had an intermittent problem for a > long time, and I should not have had to tweak it as far as it wanted > to go. The receiver portion has not failed in the few weeks since it > decided to start seeing satellites again. Maybe because I had > tweaked the oscillator?
I have an ancient 9390 that has an ancient Trimble GPS board in it that takes a 16.368 reference synthesized from the 10 MHz standard in a PLL loop with a VXCO. This is used in the L band downconversion... and for timing generally and given that is PLL derived from the 10 MHz quite likely if the 10 MHz is significantly wrong the receiver won't find satellites. I remember I had to fix this PLL in my box before the receiver in that box would lock up... initially the PLL wasn't locked, but the 16.368 VCXO output WAS present - so for that receiver it has to be pretty close to right on to work. -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either." _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.