[time-nuts] FRK and TS-105A

[Magnus Danielson]

Hi!

Could somebody from the top of their head give me the most useful 
pointers on FRK rubidiums? I now have one as part of a box, and 
naturally I want to stash up on the information.

The rubidium locks nicely, if just patiently sitting there and waiting, 
and the designers of the box was nice enough to dedicate a status view 
to the rubidium monitoring voltages and lock status.

The box itself is a Ball Efratom TS-105A measurement box, which crunches 
out frequency offsets and allan variances for 100 ms, 1 s, 10 s and 100 
s directly on the screen. All under the control of the awsome CPU powers 
of 6502.

The box works, but I am trying to collect info on it.

The box will run in either single mixer or double-mixer mode. It accepts 
5 MHz and 10 MHz. Each counter channel receives a signal conditioned 
input and 10,00001 MHz from the Rubidium. It hits the mixer after an ECL 
driver and is then amplified in LM108 and comparator LM111.
 From there will a cascade of TTL chips count it, presumably in the 10 
MHz from the rubidium. For 1 s this gives a resolution of 1E-7/1E6 = 
1E-13 which isn't too shabby. The only SMD component seen so far is the 
cap sitting directly on the mixers terminals. I have not retraced the 
card in detail so far, just looked at it breefly (out of curiosity 
naturally).

If someone has manuals for the TS-105A I will be happy, TvB has promised 
to locate his..

This box is from 1985, so it is not cutting edge, but it is functional, 
direct and a bit fun, so why not. :)

It would be fun if it could crank out the observables directly on serial 
port or so...

My beast doesn't have the GPIB interface. It may be a matter of hooking 
up a cable, but in that case it is undocumented.

Cheers,
Magnus