[time-nuts] moon bounce for synchronization

Dave M dgminala at mediacombb.net
Sat Jan 30 20:06:01 EST 2016


The counter is definitely a 5245L.  See attached (enlarged) image.  To the 
left of the gent's head is another 5245L with a 5264A Preset Unit plugin.
This all reminds me of my time in a Calibration Lab after my Navy enlistment 
was over.  These models were my bread &* butter for several years.  Great 
stuff for its time, and still useful on a bench.

Cheers,
Dave M


Jeremy Nichols wrote:
> If you look closely at the picture, you'll see that it's an "L," but
> there isn't quite enough resolution to say whether it's a 5245L or a
> 5248L. Probably 5245L because most 5248s had the hi-accuracy (for the
> era!) standard and were sold as 5248M.
>
> Jeremy
>
>
> On 1/30/2016 11:47 AM, Norm n3ykf wrote:
>> HP 5245M to be exact. There's one in my rack. Different plugin, same
>> time base. Still works at 5 GHz.
>>
>> On Saturday, January 30, 2016, Jeremy Nichols <jn6wfo at gmail.com>
>> wrote:
>>> Ooh! Ooh! Not only a 5245 with a 5265 voltmeter plug-in but a 5360
>>> Computing Pig! Great picture, thanks for posting it.
>>>
>>> Jeremy
>>> N6WFO
>>>
>>>
>>> On 1/30/2016 6:16 AM, jimlux wrote:
>>>
>>>> This month's historical picture from JPL
>>>> http://beacon.jpl.nasa.gov/historical-photo-of-the-month
>>>>
>>>> This atomic clock was used at the Goldstone Time Standards
>>>> Laboratory in 1970, to synchronize clocks at Deep Space Network
>>>> stations around the world. This master clock was accurate to plus
>>>> or minus two millionths of a second, when compared to clocks
>>>> maintained by the National Bureau of Standards and the U.S. Naval
>>>> Observatory. In the late 1960s, JPL had developed a moon bounce
>>>> technique to transmit signals from one deep space antenna to
>>>> another. Experiments included periodic measurement of timing
>>>> signals that were reflected from the surface of the moon, to find
>>>> out if the station clocks were within allowable limits for
>>>> accuracy.  Time-nut will recognize, of course, that none of the things 
>>>> in that
>>>> picture are actually an atomic clock, although they are thing that
>>>> are useful if you have an atomic clock.
>>>>
>>>>
>>>> Note the sophisticated temperature monitoring system.
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