It appears to be a "Bradley Lab #6A", Alan Bradley is now part of Rockwell Automation.
John. O,n 25 Jan 2012, at 05:18, J. Forster wrote: > Self generating, therefore selenium (or possibly silicon). There is no > bias so it's not a photoconductor. I'm sure it's called out in the -24P > manual. > > -John > > =============== > >> Thank you everyone for your comments, and if I've got it right Brooke, if >> you paste this into your browser: >> >> http://www.flickr.com//photos/75ohm/sets/72157629019710615/show/ >> >> you should get a quick tour and a movie! >> >> This is indeed a tuning fork driving a synchronous motor that has a >> perforated disc on its shaft. The whole unit operates as it should and the >> quality of manufacture is superb, so I'm reluctant to pull it apart but I >> am curious as to the type of photocell it uses. It seems very small and >> the dates on many of the components suggest manufacture in the mid to late >> 1950s so what was around to do the job at that time? There is no cathode >> bias on the "voltage amplifier" that it feeds which suggests it s >> Photovoltaic rather than Photoconductive. >> >> Thanks again for your replies, >> >> John H. >> >> >> On 24 Jan 2012, at 22:34, Brooke Clarke wrote: >> >>> Hi John: >>> >>> Is there a photo of the freq std on line? >>> >>> Have Fun, >>> >>> Brooke Clarke >>> http://www.PRC68.com >>> http://www.end2partygovernment.com/Brooke4Congress.html >>> >>> >>> John Howell wrote: >>>> Thanks Bob, >>>> >>>> If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100, >>>> 120, 140, 160, 180, 190Hz. >>>> >>>> John. >>>> >>>> On 24 Jan 2012, at 22:09, Bob Camp wrote: >>>> >>>>> Hi >>>>> >>>>> Sounds about right for calibrating / verifying vibrating reed >>>>> frequency >>>>> readouts. >>>>> >>>>> Bob >>>>> >>>>> -----Original Message----- >>>>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] >>>>> On >>>>> Behalf Of John Howell >>>>> Sent: Tuesday, January 24, 2012 5:00 PM >>>>> To: Discussion of precise time and frequency measurement >>>>> Subject: [time-nuts] US Army Frequency Standard >>>>> >>>>> Hi All, >>>>> >>>>> I recently obtained a curious Low Frequency Standard dating from the >>>>> late >>>>> 1950s. Its output can be switched to a number of frequencies from 10 >>>>> to >>>>> 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US >>>>> Army" >>>>> with a type number TS-65D/FMQ-1. >>>>> >>>>> >>>>> Does anyone have any information about this unit, in particular what >>>>> it was >>>>> used for and why the strange negative going pulse output and specific >>>>> frequencies. >>>>> >>>>> Thanks in advance, >>>>> John H. >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> _______________________________________________ >>>> 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. >> >> >> _______________________________________________ >> 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. _______________________________________________ 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.