There is probably nothing wrong with it. Two things to check: first, the lock range is super-narrow. Make sure that the 10811s are very close to each other using the manual trimmer(s). For the same reason, both OCXOs will need to warm up for a few minutes.
Second, the 5345A needs an unusually-strong signal at the external reference jack, about +6 dBm or better if you're driving it from a 50-ohm source. The input load is actually in the 1K neighborhood, not 50 ohms. I've added a MAV-11 MMIC at the external-input jack on the A8 assembly on both of the 5345As I've owned. None of my gear has had problems running from a CATV splitter on the Thunderbolt, except the 5345A. -- john, KE5FX > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of [EMAIL PROTECTED] > Sent: Friday, December 29, 2006 3:41 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] HP 5345A > > > On Fri, December 29, 2006 19:01, Colin Bradley said: > > I just picked up a 5345A from eBay. This unit has a 10811 oscillator > > instead of the 10544 depicted in the manuals I have. The serial > number has > > been removed. Does anyone know if there is an EFC adjustment for this > > counter or is the course control the only way of setting frequency? > > Colin > > I have another problem with my 5345A. It works fine using the internal > oscillator, but when feeding an external oscillator (in this case an 10811 > from another counter) it refuses to do anything. > > Is this a common problem, or is there som kind of magic involved that > needs care in the phaselocking of the internal oscillator? > > _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts