IMHO these units are designed for cooling by airflow around them and minimal conduction cooling. With my unit there is minimal heat flow from the unit to the PC board it came attached to. I am going to simply cut down the board a bit and mount it in a small plenum made of FR4 and use a small fan with controller. This will be simple and get heat out from all sides. It should be the closest to the way it was intended to be cooled, improved with the temp control, and still be small enough to be placed into other equipment.
On 01/18/12, J. L. Trantham<jlt...@att.net> wrote: Use one of your 'locked' Rb as the 'standard' and then look at the 10 MHz from the 'problem child'. See if you can adjust C217 (I think. Look at the archive.) to bring the 10 MHz signal close to the 'standard'. Perhaps the oscillator is just out of 'range' and can be brought back into range where the loop can lock it. Or maybe that is what you have already done. Both of my units get quite 'toasty'. Joe -----Original Message----- From: [1]time-nuts-boun...@febo.com [[2]mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Newell Sent: Tuesday, January 17, 2012 10:31 PM To: [3]time-nuts@febo.com Subject: [time-nuts] FE-5680A won't lock Just got my 3 in from nichegeek. Paid Thursday, shipped Friday, arrived this evening. Wow. (Actually arrived too quickly--I don't have my t-bolt running, so I can't easily do an accurate frequency check.) Two power up and lock in <3 minutes. One powers up, gets toasty, and gives 10MHz, but no lock and no PPS. The tuning config on all three read back as 0. I've set the problem child to near +/- FS and about +/- 25% of tuning range: still no lock. Any suggestions on what I should look for or try? I'm not quite ready to throw in the towel and contact the seller. -- newell N5TNL _______________________________________________ time-nuts mailing list -- [4]time-nuts@febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [6]time-nuts@febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:time-nuts-boun...@febo.com 2. mailto:time-nuts-boun...@febo.com 3. mailto:time-nuts@febo.com 4. mailto:time-nuts@febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 6. mailto:time-nuts@febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts _______________________________________________ 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.