[time-nuts] Efratom PC-10

[Don R]

In an eBay search I found several PC-10s for sale.  One of them had a Ball logo as part of the model/serial number sticker.

Ball Efratom Division PC-10 Portable Clock ATOMIC CLOCK


Don Resor
N6KAW

Sent from someone's iPhone

> On Nov 1, 2019, at 12:04 AM, David Bliss <n8qg at dbsi.org> wrote:
> 
> After many yeaqrs admiring form afar, I've acquired my first
> piece of timenuttery, an Efratom PC-10 portable rubidium clock, S/N 101
> (possibly the first production unit?).  It has the usual decade sine
> and ttl outputs plus a front panel intervalometer or clock, or at least
> that's as much as I've figured out since it came with no documentation
> whatsoever
> 
> It warms up, the unlock light and crsytal adjust lights go out, and it
> seems to keep time as accurately as anything I can measure it against
> (no surprise).  The 10MHz output beats dead on to my recently retuned HF
> rig. 
> 
> It's a great little unit but I could use some more information on e.g.
> the phase shift adjustment which seems to allow you to discipline it
> with a front panel 1PPS input but isn't super obvious, as well as
> maintenance, calibraiton, and test.  
> 
> As far as I can tell Microsemi, who bought Microchip, who bought
> Symmetricom, who bought Datum, who bought Efratom, have never heard of
> this adorable little beast, nor has the internet.  Google image search
> mostly returns pictures of my unit (I know there's at least one other
> one out there as it has a different front panel switch). 
> 
> It's based on an Efratom FRK-H oscillator, but does anyone know anything
> at all about the PC-10 specifically?  I'd love any docs you have.
> 
> Some quick and dirty photos at
> https://www.flickr.com/photos/9100973@N06/albums/72157711587895206 --more to come.
> 
> thanks,
> david n8qg
> 
> 
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