[time-nuts] HP-5065a bought and finally working!

EWKehren at aol.com EWKehren at aol.com
Wed Aug 22 21:18:48 UTC 2012

You can discipline a HP 5065A easily using a Shera with the  Tbolt  1 PPS 
and a LTC 1655 DAC in stead of an AD 1861.
Bert Kehren.
In a message dated 8/22/2012 8:23:06 A.M. Eastern Daylight Time,  
jltran at att.net writes:


Congrats on getting the 5065A up and  operational.  Make sure the A11 Board
(Temperature Controller) is all  OK.  Failure there can destroy the A12 RVFR
Assembly.  There is a  lot of 'expertise' on the list for this unit.

What is the serial number  of your unit and what is the part number of the
manual you have?

I  have a couple of manuals and I may also have the 'change sheets'  that
updates the manual to your serial number.  It may take me a while  to chase
that down but if I have the 'change sheets', I can scan them and  send them
to you.

I have not heard of anyone 'disciplining' the  5065A by GPS, other than by
hand from week to week.  However, the 105B  has a built in connection on the
back that is great for that purpose  (negative slope, as I recall) and I 
done that using a Brooks Shera  controller board and the 1 PPS from my 
It works quite  well.


-----Original Message-----
From:  time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of  Edgardo Molina
Sent: Wednesday, August 22, 2012 12:22 AM
To:  time-nuts at febo.com
Subject: [time-nuts] HP-5065a bought and finally  working!

Dear Group,

I wish you well.

Do you recall a  message and thread about a month ago with my concerns about
buying a used /  unknown condition HP-5065a rubidium frequency standard? I
bit the bullet  and bought it. Almost mint condition (cosmetically speaking)
and with  several operational issues. 

Well, It took me several weeks to put it  back to work. Several capacitors 
several boards along with a couple of  transistors and an IC were replaced.
After that any being bored by the  yellow light, it finally came off to 
a beautiful green lock condition  light. I went through the necessary steps
to tune it and calibrate it. Now,  as I have been told recently. "You have
been bitten by the Time Nuts bug."  I am not complaining at all.

Now the technical issues if you kindly  allow:

a. Does anybody have an HP-5065a manual for the latest versions?  Mine 
I downloaded from the Internet) is intended for earlier  versions. It seems 
have one of the last produced units. I would kindly  appreciate any help on
this and I am willing to pay for time and expenses  to anybody who could
help. During the repair process I found several  differences in the earlier
versions design and had to figure out hoy mine  works.

b. Is it possible to build a GPSDRb? I would like to know if it  is
reasonable to pursue the goal to discipline the 5065a with a TB which I  
got recently. 

c. I am waiting for the delivery of a recent  purchase. An HP-59309a Digital
Clock to go with the HP 5065a. How I wish I  could find the optional LED
integrated optional clock and 1PPS output. Is  my purchase a good match for
the 5065a? Any other suggestions to drive a  clock?

d. I am waiting also for de delivery of an HP-105b mint  condition quartz
frequency standard. Would a second 59309a make sense to  use it with this
quartz standard? Or just saving it for a Cesium? Anybody  willing to sell a
spare, dust gathering, clean unit to me?

e. Any  suggestions for software of lab equipment to measure my experiments
like  AD, jitter, phase comparisons, etc?

While I wait I am doing some  experiments with a FE Rb standard to 
an Adret synthesiser to  output 32.768 KHz to directly drive a Nixie clock
kit I just finished  building.

Your comments are surely welcome. Thank you!

Kind  regards,

Edgardo  Molina

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