https://www.febo.com/pipermail/time-nuts/2017-May/date.html
The poster at http://www.simonsdialogs.com/2016/09/a-thermal-fuse-and-hp-10811-60111-repair/ reported that the thermal fuse saved an oscillator from destruction when a thermistor opened. HP made thousands of these which sold for $800. If a large portion failed it would have been addressed. They raised the temperature of the thermal fuse to reduce nuisance blows. I say that nuisance blows equal to real blows are worth the trouble. You may be getting oscillators on the surplus market or eBay which have a higher proportion of nuisance blows. πθ°μΩω±√·Γλ WB0KVV From: Mike Feher <mfe...@eozinc.com> Date: Tue, May 9, 2017 at 9:10 PM Subject: Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Respectfully I disagree. I have totally shorted out numerous oscillator’s fuses with no problems. The design of those thermal fuses makes them vulnerable to opening just due to years of use without problem, in any of the electronics. My shorted out oscillators still work. Ideally, if handy, it is easy enough to replace them if one is available. They just plug in. If there is a thermal runaway, that caused the opening, to me that implies that there are other issues. Regards – Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 848-245-9115 _______________________________________________ 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.
