Max, most interesting comment!
So far you are the first person from which I hear that he has exchanged the lamp. If I am wrong concerning the difficulties of lamp exchange: Even better so! I just checked the Dow Corning web pages to find 373 different products that have "Silastic" in their name. Which of them did you use? 73s de Ulrich, DF6JB > -----Ursprungliche Nachricht----- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von Max Skop > Gesendet: Mittwoch, 12. Marz 2008 10:42 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] Rubidium Oscillators and Racal 1992 > > > Hi all, > I have replaced the lamp in an FRK with out to much trouble. > When I got the > unit it had no output so I purchased a couple of lamps on > e-bay for $30 ea. > The glue holding the lamp looked like Silastic. I cut the > glue with a small > knife and removed the lamp intact. I filled the holder with > new Silastic and > pushed the new lamp in to the same depth. Allow to dry and a working > oscillator. Initial start up took about 15-20 minuets before > lock came on. > Its not hard to do and well worth the result. Does anyoneone > need a well > used lamp slightly yellow in colour? > > Regards > Max VK3YBA > > > ----- Original Message ----- > From: "Ulrich Bangert" <[EMAIL PROTECTED]> > To: "'Discussion of precise time and frequency measurement'" > <time-nuts@febo.com> > Sent: Wednesday, 12 March, 2008 5:20 PM > Subject: Re: [time-nuts] Rubidium Oscillators and Racal 1992 > > > > Gentlemen, > > > > I would like to place emphasis to the fact that the so called "lamp > > voltage" is just the operating point of a regulation loop > in which the > > lamp's health is ONE of the involved parameters, exactly as > Antonio's > > experiments verify. > > > > Within the lamp a plasma ignition is excited by means of an > external > > electromagnetic field. The field's frequency as well as the lamp's > > temperature (which is in the near of 110 ?C) are important > parameters > > for the quality of the plasma ignition and for where the operation > > point of the loop is. > > > > When Antonio was "Adjusting the capacitive trimmer solid > with the lamp > > assembly (and) the lamp-V ranged from 1.5 to 6.5 V" he demonstrated > > the dependance of the operation point from the exciting field's > > frequency. Not sure whether the LPRO also has, but the FRK-Ls have > > trimmers for the temperature setpoint of the lamp's temperature > > controller. Would he have changed that he would have observed a > > similar dependance. And when "the lamp-V oscillates within 10 > > milliVolt basicly according to ambient temperature" this is > simply the > > effect of the temperature controller's inability to control > the lamp's > > temperature perfectly despite of ambient temperature changes. > > > > So a better phrase would be that the lamps voltage is an > indicator of > > the lamp's health IF and ONLY IF everything else is sane. > Don't blame > > the lamp before you have checked the temperature and the exciting > > field's frequency. > > > > I am stressing this a bit because exchanging the lamp is > not exactly > > easy! While it is a snap to remove the lamp toghether with the lamp > > holder (a small metallic part that makes the whole thing > look like an > > ordinary bulb) the lamp itself (which is ONLY the glas > compartment) is > > glued (?) to the lamp holder and in order to exchange the > lamp I guess > > you will need to destroy the current one and the glue in > the new one. > > > > Has anyone of you already performed that action or can give an clue > > which adhesive is suited for that purpose??? > > > > Best regards > > Ulrich Bangert, DF6JB > > > >> -----Ursprungliche Nachricht----- > >> Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > >> Im Auftrag von > [EMAIL PROTECTED] > >> Gesendet: Dienstag, 11. Marz 2008 15:31 > >> An: time-nuts > >> Betreff: Re: [time-nuts] Rubidium Oscillators and Racal 1992 > >> > > > _______________________________________________ > 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. > _______________________________________________ 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.
