[time-nuts] Efratom MFS system Questions

[Bob kb8tq]

Hi

It’s been more than a while since I last tore into one of those beasts.
My recollection is that the output modules have a set of buffer amps 
on them. Each buffer has filtering appropriate to the designated output
frequency. One *could* convert a 5 MHz module to 10 MHz by swapping
out a bunch of coils and caps. Then you need to work out the mystery
of how to feed it. If the main box just has a 5 MHz OCXO and 5 MHz
Rb …. not so easy. If it’s a 10 MHz main box and the 5 is divided, then
indeed pretty easy. 

Bob

> On Jul 19, 2019, at 4:21 PM, Walter Shawlee 2 <walter2 at sphere.bc.ca> wrote:
> 
> I got a nice system a while back (Modular System *808-400-14*) with both rubidium and crystal oscillators.
> I am getting some faults showing up, and need some insight into system operation and how to fix it.
> 
> I got all the docs on the FEBO site which were very helpful, but they do have have answers to my most pressing questions. These are issues I am trying to solve:
> 
> *MBF front and rear modules:* The front unit (no jacks, only a fault light) seems to be what sets the division for rear buffers (yes/no?) however, I cannot see any relationship to the alphanumeric part numbers in the FEBO docs, and the all numeric parts numbers on the actual units. Is there anything explaining what module number is what type?  Can the rear buffers be of different types, for say 5Mhz, 10Mhz, etc. all in one frame, or does the front MBF module set the *only* frequency available?  I am getting a fault light on the front unit, and back ones are outputting a varying (wrong) frequency.  the rear buffers are nominally 5Mhz, can I make them 10Mhz through any mods?  seems like it should be possible if I had the manual for this module type.
> *
> **MXO Crystal Oscillator module:* How is this adjusted?  I can see no access, and it is off frequency. I can't imagine a way to set it out of the frame, so it feels like a way must be possible to do it while installed, but what is it? I found the info for adjusting the Rubidium, so I feel it must be out there somewhere.
> 
> *Is there any hope of manuals for any modules?* *How about connector maps or frame drawings?* Efratom became Symmetricom, then Microsemi, and now everything MFS related seems to be lost. Two days of web searching did not turn up anything useful, so I am hoping someone has info on the list they are wiling to share. *Any chance of module extender cables?**
> *
> any help appreciated, as this is a wonderful unit that cries out to be fully operational in my lab. I am happy to send parts from two *Efratom 1PPS Drawers* I have (with *MDP/MPS/BFM/ACI* Modules-black in color, probably not compatible with the MFS units) to anybody that has useful info or parts to share.
> 
> all the best,
> walter
> 
> -- 
> Walter Shawlee 2
> Sphere Research Corp. 3394 Sunnyside Rd.
> West Kelowna, BC, V1Z 2V4 CANADA
> Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
> +We're all in one boat, no matter how it looks to you. (WS2)
> +All you need is love. (John Lennon)
> +But, that doesn't mean other things don't come in handy. (WS2)
> +Nature is trying very hard to make us succeed, but nature does not depend on us.
> We are not the only experiment. (R. Buckminster Fuller)
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.