VTVM question

[Mark Graalman WB8JKR]

  Hi Stu,

  I was just messing around with robbing a regulated 1.4 volts
from the filament supply and eliminating the battery. I had
it working well, but in order to have enough standing
current in the regulator (two silicon diodes in series) to
keep the internal resistance of the supply low enough not to
screw up the accuracy of the ohm meter in the low range
I decided it placed too much load on the meter's transformer
so I gave it up and put the battery back in. Rather change a
battery once in awhile than maybe replacing the transformer.  ;^)

Mark  WB8JKR


On Sat, 6 Apr 2002 14:24:11 -0800 "Stu Lyon" <slyon at pacificnet.net>
writes:
> Mark,
> On my V-7A, which *should* be similar to the IM-18,etc, I measured
> 135 mA
> under the conditions you stated. The VTVM showed 0.6 ohms, which is
> the
> internal resistance of the multimeter I used.
>
> Just out curiosity, why do you need this information?
>
> 73, Stu W6CUX
> Winnetka, CA
> slyon at pacificnet.net

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