[time-nuts] could you please post this?
rjb0343 at aol.com
rjb0343 at aol.com
Mon Dec 21 16:45:26 UTC 2009
FTS 6102 Frequency Comparator -info needed
Does anyone have any info on this Frequency & Time Systems unit? I have 3
and each is slightly different externally but the innards seem to be the
same. Each unit has a low 2-digit S/N so I’m not sure how many were actually
made or if any of them were production units. I.C. date codes indicate a
1987 date. I have quickly checked the circuit board to see if I could figure
out what goes on and have included a link to a photo of the input section
of the circuit board. There are 2 floating BNC inputs (A & B) that go
through isolation transformers to buffers then to a phase detector. From the
parts used it appears the circuit might be usable from near d.c. to about
100Mhz. The phase detector gives a d.c. voltage proportional to the phase
difference and seems to be followed by RC low-pass filtering feeding the op-amp,
which seems to make sense. There are 2 output BNC connectors marked ‘A-B’
and ‘analog’
There are also two LM211 voltage comparators that may be used to trigger
the 8-digit counter chip that drives the front panel display. You can select
3 of the 8 digits with a switch and apparently the numeric value of that
3-digit number is converted with a 12-bit D-A converter to drive a recorder
or whatever. Four decade averaging periods are also selectable. There is
also a 25 pin ‘D’ connector on the rear marked ‘controller’ but I’m not
sure what that does as if it doesn't seem necessary to use the unit as a
comparator. A quick test indicates the units at least work. More testing is
needed to see how useful they might be.
Any information would be appreciated. -Richard
Front Panel photo link
_http://farm3.static.flickr.com/2665/4203550480_70f27cb15e.jpg_
(http://farm3.static.flickr.com/2665/4203550480_70f27cb15e.jpg)
Circuit Board photo link _
http://farm3.static.flickr.com/2785/4203550698_cb648b4e35.jpg_
(http://farm3.static.flickr.com/2785/4203550698_cb648b4e35.jpg)
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