Mercury Model 204 Retail Tube Tester??

[Tubejunke]

Thanks Terry, really the tester basically works but there is no way to set the meter to a cetain # off of the chart before the tube is inserted, per instructions. In other words the rheostat that you use to select this setting no longer has an effect on the meter. I know the rheostat itself is good because I can hold down the TEST button and turn it and see its effect on the reading. The effect on a tubes result is a lot with little turn of the rheostat so this is a critical setting.

Probably like most things there is some bad resistor or capacitor causing the trouble. If anyone has parts for old testers I would like to replace the meter assembly. My needle is broken, which throws the calibration off quite a bit.

I don't think this unit is one of the cheap emissions only testers. It has a gas and a shorts test. The Lafayette price tag is still on it for $349.95. I don't know its exact age. I do know that I carried bags of tubes to that store and used it back in the late 70's and it wasnt new then.....