That remembers me the ugliest (or most exotic?) frequency divider i ever saw:
It was part of a Marconi (damn, i don't remember the model number, but it was an OOOOOLD model), more precisely the 600 MHz divide by ten prescaler. The input divider was based on two tunnel diodes that acted as a div. by two divider followed by the really most bizarre divide by five unit i ever saw: Fifteen discrete NPN transistors arranged in a star (or pentagon (Helloooo Echelon!! ) ) topology with the input placed at the center of the star. The 15 transistor were in a symmetrical loop of 5 three transistor units working in a closed loop. Years later, i've made searches to find the schematic of this prescaler, but without the model number, this is quasi-impossible. If one of this forum's members has this schematic, i would be pleased to ask for a copy! Damn! That strange "star" all-transistor divider could count up to 300 MHz after all!!! Have a good day gang and keep this forum running!! 73 de Normand Martel VE2UM Montreal, Quebec, Canada --- Randy Warner <[EMAIL PROTECTED]> wrote: > Tom, > > Attached is my entry in the butt-ugly PPS divider > contest. A whole lot > of 74HC192's and 74HC74's. I think this is circa > 1999 or so. > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Tom Van Baak > Sent: Tuesday, August 08, 2006 2:16 PM > To: Discussion of precise time and frequency > measurement > Subject: Re: [time-nuts] Frequency Dividers > > Let me add this photo - I found in a box my first > attempt to make a PPS > divider as well as an early breadboard prototype of > the much simpler, > PIC-based, divider. > > http://www.leapsecond.com/pages/ppsdiv/ver1.jpg > > /tvb > > > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
