[time-nuts] Ugly Frequency Dividers

[Normand Martel]

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 <Randy at synergy-gps.com> 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: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] 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
> 
> 
> 
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