I'll have to check (dig it out from under a pile of gear.....) but if I remember correctly the HRO receiver (at least the early, pre-war, ones) had a 'non-contact' crystal holder for the IF notch filter. The crystal was a block about 1/2" square and a bit less thick (-ish) and fitted loosely between two support plates which incorporated the electrodes. It was certainly not a tight fit and the crystal could be easily removed.
Paul Reeves G8GJA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Chuck Harris Sent: 21 April 2014 14:01 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] optically excite a quartz crystal? I'm puzzling over this statement. The FT-243's I have seen have a spring that squishes the quartz blank between the electrodes. They aren't plated onto the quartz, but they are still in intimate mechanical and electrical contact. -Chuck Harris Bob Camp wrote: > Hi > > The WWII era FT-243 is one example of a crystal that has the active portion > of the > electrodes separated from the resonator by an air gap. There are lots of > similar > holders from that era that do pretty much the same thing. Non-contacting > electrodes are not very new. > > Bob _______________________________________________ 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. _______________________________________________ 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.
