[time-nuts] HP 115CR Clock Powerup / Documentation

Hugh Blemings hugh at blemings.org
Thu Dec 22 18:29:01 EST 2016


I've been fortunate enough to acquire a HP 115CR Frequency 
Divider/Digital Clock - it's electromechanical and I suspect built in 
the mid/late 60s - just slightly older than your humble correspondent.

It's similar though not identical to the 115CR shown here 

I'd like to fire it up - given it's age my thought was to use a current 
limited 24V bench supply and slowly ramp up the voltage the first time - 
would welcome any thoughts on this.  I gather from the supporting 
documentation for the powersupply it's rated at drawing ~250mA

I've been unable to locate a scan of the owners manual or service manual 
online.  Have looked at time-nuts archives, leapsecond.com and hparchive 
to no avail.  There does appear to be a hardcopy available for purchase 
- happy to fall back to this if necessary, but any pointers welcome.

My goal ultimately is to have it on display running, synchronised to a 
GPS disciplied 10MHz source :)

Any thoughts and feedback welcome - this is my first foray into old 
clocks :)

Kind Regards,

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