This tube tester was tested and it does work.

Semi-remote cutoff triodes/frame grid. Intended for use as VHF RF amplification in black and white OR color television receivers. New in Box (NOS). We have hundreds of thousands of tubes for manufacturing purposes, all vintage american made. 2 If you are looking to re-tube and amplifier, guitar amplifier, preamplifier, compressor, equalizer, microphones or any tube equipment, send us the model number and we will take care of the rest, and generate a custom listing for you. 4 We carry most USA made brands such as RCA, GE (General Electric), Sylvania, Raytheon, TungSol and PentaLabs , just to name a few. 5 We also carry european brands such as Amperex, Mullard, Telefunken and Marconi , just to name a few but in less quantities.