[volt-nuts] New Solartron 7081

[J. L. Trantham]

A ‘new’ 7081 arrived this week and is making itself at home.  It seems to be
working normally, passes the ‘Self Test’, and I am able to communicate with
it via the RS232 interface.  I down loaded the CALDUMP and archived the
data.  The firmware is a ‘DC’ version on this SN 000660 unit (displays ‘VDC
BSW 17 Ma 85 13 17’ via the RS232 when ‘Initialise’ is selected) as opposed
to a ‘DD’ version on my SN 001523 unit (displays ‘VDD BSW 8 De 86 8 50’).

 

I have archived IC430, IC415, IC414, IC413, IC412, and IC803 from both
versions if anyone needs them.  I think the ‘DD’ version is already on the
web at a couple of locations.

 

Now, a couple of observations and questions.

 

1.	The CALDUMP revealed a Zener Current Token Value of 103.  The
sticker on the back corner of PCB 5 says ‘HC/20/27. 103’. The Zener Current
Token Value appears at the same location on my other 7081.
2.	The ‘Cal Key’ that I have, sent to me by another list member, that
is used to switch from Norm to CAL to be able to read the CALDUMP and
calibrate the meter, fits this new meter.  That makes maybe 5 meters that
have worked with this same key.  If anyone needs a copy of the key for their
meter, let me know.
3.	When the input is shorted, I see about 0.15 uV.  When reading my
Fluke 731B, I see about 10.000770 volts while my other 7081 (Cal’d by Ametek
in October) shows about 10.000030 volts.  I think this means the new guy
needs to be calibrated.
4.	B1, the battery on PCB 3, a Tadarian TL-2150, ½ AA, 3.4 Volt
battery, reads 0.016 volts.  That sounds dead to me and probably means I can
power down the meter, remove and replace the battery with no loss of data.
5.	B401, the rechargeable battery on PCB 14, a Varta 3.6 V, 100 mAH, 3
pin battery (two + pins, one – pin), measures 4.368 VDC with power on and
0.993 VDC with power off.  That sounds like it needs to be replaced.
However, I am suspicious that if I remove it with power off, calibration
constants will be lost.  Is that correct?  If not, is there a specific set
of steps to do to ‘recover’ from the battery replacement?
6.	The meter is missing the feet and the ‘bail’.  Might anyone have
some spares?

 

The meter is quite clean inside, date codes are mid to late 84 and the
firmware chips appear to be ‘updated’.  I will plan to update it further to
the ‘DD’ version.

 

Any other suggestions or advice appreciated.  It looks like it will be a
good addition to the bench.

 

Thanks,

 

Joe