[volt-nuts] Fluke 732A Questions

R.Phillips phill.r1 at btinternet.com
Sun Dec 29 09:39:46 EST 2013

Hi Joe
I also obtained a Fluke 732A back in October last, and I have fitted a new 
set of SLA batteries and it is working just fine - I am still very impressed 
by its accuracy and stability, and its build quality.
First, the external 3-pin power socket is a HYPERTRONICS 'D' type connector 
(female) type 100-166 - but I have not found one to date !
I also expected the temperature monitoring thermistor to give a 3 to 4 K 
ohms, as indicated in the manual P/N 645051 dated May 1983 - but I guess 
that you have a later model as I do, mine being serial # 4845***, some 
modifications were made,and I understand that this included a change of 
thermistor, so the standard reading is in keeping with your result. My unit 
gives a very stable 4.520 K ohms, being between 4.52080 and 4.52090 K ohms. 
Judging by your findings, you are also using the 1983 copy of the User 
Manual - we could both use a more up to date issue.
I am awaiting the repair of my 3458A - so I am having to rely upon a 
recently calibrated Keithley 2015 and my good old 3456A - but they both give 
very impressive results - The Keithley giving 1.000007 volts for the 1 volt 
output, and 10.00000 volts for the 10 volt output (how I miss that final 
Looking forward to your further results and any other owners comments.
Best regards


-----Original Message----- 
From: J. L. Trantham
Sent: Saturday, December 28, 2013 10:51 PM
To: volt-nuts at febo.com
Subject: [volt-nuts] Fluke 732A Questions

I have reviewed the prior postings on Volt-nuts (a very rewarding review,
BTW)) regarding the 732A and have two questions:

1.        Has anyone determined the part number, or a source, for the mating
plug to J10, the external power connector for the 732A-7005 battery pack?  I
noted some postings recently about this but did not find a definitive
response regarding the identity of this plug.  The alternative would appear
to be a complete replacement of J10 and its plug, as long is it all fits in
the opening in the panel.  I hate to 'bore holes' in vintage equipment.

2.       The oven thermistor in my 'new to me' unit measures 4229 ohms (+/-
an ohm or two) after the unit has warmed up for a week or so.  I note the
manual refers to 3K to 4K for the value of this thermistor when the unit is
'stable' as well as other's posting values in the mid 3500's ohms for their
units.  Should I be concerned?  The unit seems to be stable to within about
2 uV over about a week (as measured by my 3458A - see below).  Should I open
the unit and try to measure the oven temperature or just be satisfied that
the unit seems to be working?

I had to replace the four 6V 4AH SLA batteries and they charged up
appropriately as judged by the front panel LED's.  I had to remove the
'jumper' for the '40' option on the A7 board and connect the jumper to the
'20' and '10' options (total of '30') in order to get the unit to adjust to
10.0000000 VDC on my 'Agilent In Cal'd' 3458A.

The need to change the jumpers, perhaps, could be just an ageing issue or,
on the other hand, a 'temperature' issue with the oven.

Should I open the unit and directly measure the temperature (supposedly
about 48 degrees C) or just be satisfied with what I have?

My recently added 735C also needed moving some 'jumpers' in order to get it
'on scale', as determined by my 3458A, although it's thermistor measures
about 3330 ohms (after being on for several weeks).

Thanks for everyone's help.


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