[time-nuts] Antique 5061A option 004

J. L. Trantham jltran at att.net
Mon Oct 15 18:30:55 EDT 2012


Congrats on the 5061A!  Good price for a 'complete' unit.  Now the only
question is 'will it function'.  I have no experience with the PRS10.

I have 9 functioning 5061 variants and I will be happy to help you try to
get it up and operational as best I can.  I am a relative 'neophyte'
compared to most on the list and there are many here with much more
experience with these 'beasts' than me.

Opt 004 is the high performance tube.  Option 001 is the clock, option 002
is the battery back up, and option 003 is both option 001 and 002.
Convenient, huh?

There are at least a couple of options for manuals.  Is it 'black face' or
'white face'?

The 'white faced' units had a 5 MHz OCXO (a 105 variant) and some of the
black faced units did as well.  There is a later variant or conversion that
uses a 10811 with a divide by 2 circuit that gets it back to 5 MHz.  The
5061B had the 10811 and brought 10 MHz out to the front panel and back

Look at Didier's site and also look at Tom Van Baak's www.leapsecond.com
site and it's 'Museum of Time and Frequency' for manuals.  I have a number
of paper manuals that might add additional information specific for your
serial number but I have not looked at them specifically for this so far.

You are correct; it is a very 'addicting' activity.  Be careful.

Good luck.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of David I. Emery
Sent: Monday, October 15, 2012 4:30 PM
To: time-nuts at febo.com
Subject: [time-nuts] Antique 5061A option 004

	In a mad moment at the NEARFest flea this weekend I grabbed
a 5061A for $250.   Poor thing was getting wet in the rain and needed
a home.  Really really heavy to carry to the car, however...

	It has a high performance option 004 CBT in it (late SN
3112A02887 dated 05/93).   And a 10811-60109 OCXO.   Option 3 whatever
that is, and H29 too.   Seems to have a BNC marked C field...

	Chassis SN is 2002A01710 but a number of the modules have  late
series numbers such as 2740 for the synth, 2652 for the oven controller,
and 2448 for the AC amp..

	The unit obviously came from the Naval Observatory (similar
to Paul Swed's I presume)... has a sticker on it.

	Looks superficially as if it was upgraded various times -
wondering if anyone could suggest where a manual that would cover the
OCXO mod and others on into the 90s might be had (Artek ?) 

	I have yet to fire it up (gotta dig out a power cord I have
somewhere in the way back junque)... but FWIW (not much I am sure) I was
told it would lock "after a while".

	I suppose it is time to see if it will pump down and have any
measurable beam current - I guess at least possible that a CBT that
young might still have a tiny bit of life left.

	A question - I assume the OCXO is 10 MHz (I think all 10811s
are) and thus it obviously must be easily possible to provide a 10 MHz
output. Is there a point to attach a SMA to BNC for this ?

	It is my first Cesium, now I guess I officially have the
disease, all those Rbs and GPSDOs being just prodromal syndromes...

	I also grabbed a PRS10 at the flea (that was pretty cheap
at $50) and wonder where I might land a PBBT adapter for it cheap
too... I'd rather see if it works OK before investing in a new one
first... and that connector is a bear.

  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole -
celebration of what could have been, but wasn't and is not to be now

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