Triplett 3C V-A-O meter

This meter was a present from an old trader on a flea-market. "You like it? Take it along for free, I have no use for it.". The meter was taken apart by its former owner and parts are missing. This is a meter that can only measure DC Volts and resistance. It has a 3 but no 6 Volt range. Not an interesting instrument for a radio or car repairman. Not for an electrician either, it has no AC range. Peculiar little black box!

The chances are, it will never function again. But, what the heck? In a collection there is also room for lesser objects.

Brand name: Triplett
Modell: ?3C (model number only partly readable)
Serial no.: none found
DC range: 0-3; 30; 300; 600; 1500 V
AC range: none
Current: none
Resistance: Full scale 1 MOhm;
  ranges: 1k; 10k; 100k; 1 Meg
Sensitivity: DC: 1,000 Ohms/Volt
Instrument: 100 uA / 100 mV; Ri = 1000 Ohm
Battery: unknown
Patents: not mentioned
Year of birth: 1940 ~ 1950's ?
Accessories: non present
Manual: none
Condition: Bakelite housing few cracks, fragment missing, poor, not complete
Dimensions: H: x W x D mm

This is how it came to me. No knobs. I doubt if the sockets are original. All screws are gone. The instrument itself, works, though.

The interior, instrument face down. Real Triplett resistors!
Right side. Two wire-wound precision resistors.
Left side. Two wire-wound precision resistors.

Mind the red plastic connector. Fraud!

Range switch and potentiometer for Ohm range adjustment.

Again, the replaced connectors.

The inside of the instrument. A wire-wound resistor can be seen.

Instrument: 100 uA / 100 mV; Ri = 1000 Ohm.

Again, front view. A perfectly good working moving coil instrument. And that after half a century or perhaps even longer.
The scale. Hey, it came from Blufton, Ohio! The type number is barely visible.

When observing the print, the difference in fonts attracts ones attention. As if the ranges 0 - 1500 and 0 - 300 were printed later. Different font, different weight, different colour black.

Observe the Ohm scale: sensitivity beyond 500 Ohm is poor.

The damages and smears on the lower part of the scale suggests that the instrument has been opened before and the scale was removed before.

(C) Photo's and text: 2010 - Van Zwam Computer Support - Velp - The Netherlands - All brands and brandnames are property of their respective owners.