[time-nuts] Efratom FRS 10mhz rubidium frequency oscillator+ board

wje wje at quackers.net
Mon Jun 1 01:23:10 UTC 2009

This is a pull from a Lucent unit used to provide timing for cell sites. 
I have a couple myself.

The board is primarily a 10Mhz to 15Mhz converter. It also has some 
failover logic. Typically two independent units were installed in one 
plugin chassis.

The D connector has power in and status in, and provides status out. One 
unit is set as the primary and the other as the secondary via signals on 
the connector. The secondary then monitors the status of the primary and 
will switch to primary if the other fails.

The TNC connectors provide raw 10Mhz from the FRS, a buffered 10Mhz, and 
synthesized 15Mhz.

I did at one time have the connector pinout info, but since the board is 
fairly useless, I'm not sure I kept it. It does have some nice TNC 
connectors and a nice crystal filter, if you happen to need a 15Mhz filter.

Bill Ezell
They said 'Windows or better'
so I used Linux.

GandalfG8 at aol.com wrote:
> Bob, Fluke.1, is selling these on Ebay, for  example item #  290313671907, 
> and supplies the FRS module itself with an interface  board containing the 
> FRS connector, plus another PCB containing a  15MHz oscillator and assorted 
> other parts that the FRS interface board plugs  into.
> Connecting up the FRS itself via the 10 way header on the  interface board 
> is simple enough, most connections are marked and  others easily traced, but 
> there's no information available regarding the  other PCB.
> Does anyone have any information regarding the  purpose of this board 
> and/or connection details for the fitted 25 way D  type and TNC connectors?
> Any information on  the functions of the various jumper pins would also be  
> appreciated.
> regards
> Nigel

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