# Range Doubler meter

Discussion in 'Electronic Repair' started by mm, Nov 17, 2006.

1. ### mmGuest

I have a Micronta (Radio Shack) analog meter made iirc in the 70s that
I bought at a hamfest in the last 10 years. It calls itself, and I
remember the ads, a Range Doubler meter, and has a knob to switch from
V-A to V-A/2.

I figured that V-A/2 would give readings that are half the real
values, but it seems like it is the opposite. They are twice the real
value and I have to take that value and divide by 2 (V-A/2?).

Is this the way it is supposed to be, or did mine get miswired
somehow? Did anyone other than Micronta sell range doubler meters?

I don't use it much because when I need analog I have a Lafayette
meter I bought in the early 70's that I like better, but I think the
range doubler feature should be very helpful. I wanted the meter in
the 70's and maybe 80's but couldn't rationalize buying it new, since
I had a VOM and really needed a VTVM.

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2. ### Heinz SchmitzGuest

My Range Doubler shows 125 Volts, if I set the main knob to the
250 V range and input 125 V.
If I then set the doubler knob to V-A/2, the needle goes to 250 V,
and I have to divide by two to find the voltage at the input.

I guess they wanted to give us more ranges without having
to print more numbers onto the instrument.

Regards,
H.

3. ### Guest

Mine has sufficient scales that mental arithmetic is not needed! The
range-doubler switch reduces the sensitivity from 50KO/V to 25KO/V,
but allowes all measurements to be taken on the upper half of the
scales. For example if I am measuring 119v I can choose whether to read
the value off the 0-250v scale or the 0-125v scale. It is the Archer
28-4014A model, which i bought in 1981.

4. ### Homer J SimpsonGuest

I think so. This is a crappy idea anyway.

5. ### larry moe 'n curlyGuest

Sears sold almost the same meter as Radio Shack, for \$60, only it added
a battery test function.

6. ### mmGuest

Thanks, and thanks all.

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