I bought a box of old radio parts. Carefully wrapped in the box were two Cunningham C-302's. The tubes have vacuum "tipped" tops, brass basses with short pins and they have a golden hue. Writting on the base indicates these are transmitter tubes. Can these tubes be tested? What era are they from? Can they be used for anything other than displays? All help is appreciated. Wes

Wes

They are transmitting tubes from the 1920's. Probably best just to check the filament with an ohm meter. Used they sell for over $100 each.

Norm

: I bought a box of old radio parts. Carefully wrapped in the box were two Cunningham C-302's. The tubes have vacuum "tipped" tops, brass basses with short pins and they have a golden hue. Writting on the base indicates these are transmitter tubes. Can these tubes be tested? What era are they from? Can they be used for anything other than displays? All help is appreciated. Wes

They're "five-watt" transmitting tubes from the 1921-24 era. If they have good vacuum and intact filaments, they are okay. There is always a ready market for these among hams building replicas of old transmitters, or restoring original ones.

The tubes appear to be in great shape. I tested the pair with a Radio Shack pocket digital multimeter. On the filiment pins, one tests .8 ohms and the other .9 ohms. Does this test within tolerances to be considered good? Thanks, Wes