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Johnson Meter Compatibility

Amateur Radio > E.F. Johnson Restoration

What do the Johnson Viking 500, Valiant I and Ranger I meters have in common?

The Viking Valiant I and Viking 500 multimeters are electrcally similar but with differing meter faces. Either one of these meters can be converted to fit either application after fitting a compliant meter face.

Also, either of the Viking 500 or Valiant multimeters can be made to fit into a Viking Ranger I meter case by trimming the needle and using the Ranger I meter's hardware. The Ranger I meter is also electrically similar to the Valiant and 500 multimeters.

Here is a Viking Ranger I meter on the left, and a Valiant I meter is on the right. In this case, the Ranger meter was bad. The mounting hardware from the Ranger meter was transferred to the Valiant meter. Finally, the Valiant meter needle was trimmed to match the Ranger meter scale and then installed into the original Ranger meter case.

The rebuilt Viking Ranger I meter using the internals from a Viking Valiant meter.

Here is the multimeter found in the second Viking 500; it was found to be electrically incompatible with the transmitter. The original Viking 500 multimeter measures 20 ohms across its terminals; this replacement meter measured around 2500 ohms. Also, the meter face had been produced on cheap copy paper.

The malfunctioning multimeter was replaced with a re-faced Viking Valiant meter. The original Viking 500 meter bezels were produced in the Johnson maroon color. Unfortunately, the only replacement meter bezel on hand was black, so black bezels were fitted to both meters.

The re-faced Valiant mulitimeter meter installed in the Viking 500 front panel.

Once Viking 500 #2 was operating normally, it became clear the Cathode Current, 500 mA meter was also an incorrect meter. After testing, I believe it is a Viking Thunderbolt 750 mA meter.

Ater a month of looking (and just missing out on a good repalcement meter), I picked up a 100 mA Honeywell meter with the intention of shunting it. The shunt works out to 125 milliohms to read 500 mA full scale. Luckily, I had two Dale 1% resistors, a 200 milliohm and a 330 milliohm. In parallel, they calculate to 124.5 milliohms which is exteremly close. The shunted meter reads 500mA when compared to a NOS 1950's 500mA meter.