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'" <[email protected]> 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 -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
