[time-nuts] [Summary] HP 115CR Clock Powerup / Documentation
hugh at blemings.org
Fri Dec 23 18:24:17 EST 2016
My thanks for the various replies including to Luciano for the 115BR
manual and Chuck for the timely advice about old caps!
I'll take a put at summarising the various replies and my own
observations now I've the 115BR Manual and the 115CR unit itself - any
errors in same mine alone;
The 115CR appears to be a slightly later device - it's 2RU rather than
3RU and uses plug in PCBs rather than point to point/tag strip style
Based on a quick glance at the 115BR service manual and the 115CR unit
itself, I'd venture they are electrically and mechanically very similar,
The 115CR seems to have hard wired DC input polarity relative to ground
wheras the the BR is switchable. The 115CR doesn't have a meter or as
many frequency output options.
* Divider circuits need to be manually started using internal switches,
the unit has built in rack rails to support easy access. Similarly the
motor must be manually started.
* Many of the silver can (physically larger) axial capacitors on the
PCBs in my unit show signs of corrosion - this presumably the acid
leaking out of the tantalum caps as Chuck alluded to.
* One correspondent suggested replacing the caps right from the word go,
another to go for broke and turn it on - not sure which way I'll go yet ;)
* The mechanical odometer style display needs care not to bind up/jam.
Attention to lubrication/grease for the motor and other bearings seems
prudent. Don't force any of the mechanical components.
* Looks like I can get a paper manual here
http://www.etestmanuals.com/Search.aspx?Search=115CR - I think this will
be my next step.
I'll close for now with this quote from Chuck which may dash my plans to
have it on permanent operating display;
"These clocks are not a lot of fun to live with. They sing along
quite loudly at 1KHz."
...so might not be ideal in the otherwise quiet lounge room after all :)
Thanks again all for the input so far, will report further progress when
I return to the device in the new year after a house move :)
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