"Richard J Kinch" wrote in message
. ..
Thanks for all the comments.

As I explained elsewhere in this thread, the Mallory battery SKB-830 in a
pair must have produced about 9 or 10 volts, so I am thinking they were
each a stack of four mercury cells at 1.35 volts each, making 5.4 volts
for
an SKB-830 battery and 10.8 volts for the pair. Applying that voltage
would deflect the battery-test meter into the proper range and operate the
unit, as would a standard 9-volt battery.

As I also explained in another post, the meter unit seems to be faulty. I
did inquire from the good folks at http://www.spectrum-metrology.co.uk/
regarding their repair and upgrade services, and they would be happy to
upgrade this Talyvel 1 to a Talyvel 5 ... for USD $5600. Ouch! And
that's
not counting any needed repairs.

I am a bit suspicous of that battery number. I just looked in my 700 page
Eveready battery manual dated 1968. The Mallory mercury batteries begin
with a TR (at least the ones that cross to an Eveready number in this book),
and there were no SKB batteries, nor anything wtih "830" in the number - I
did find a RM630, which crosses to Eveready E630, that's a 1.4V battery.
I have some surplus mercury cells here, they are Duracell RM12R (1.35 V).

I show listings for 6.75, 9.45, 10.8, 9.8, 8.4, 11.2 and some other
voltages so I don't know that you can assume 10.8V