Testing a 2050 tube on Sencore Mighty Mite

The 2050 Gas Thyratron tube is a tube used in many Seeburg jukeboxes.  Even though a 2050 tube is not listed on the setup charts of Sencore Mighty Mite models TC162 and TC28, you can test them.

Settings are 6-A-5, socket #1.

The key to a proper test is that you MUST engage the LIFE TEST during emission testing to reveal a substandard tube that will not reliably handle the current levels needed.

When testing for shorts, a slight glow of the shorts lamp (TC162) or modest meter deflection during shorts test (TC28) is fine.  Only “hard shorts” are a real problem with this tube, so common sense is required here. It is not uncommon to see some minor shorts indication (which is actually leakage, not a hard short) in a gas thyratron, and for a 2050 tube, is sometimes seen at pins 6 or 8. Again, only a hard indication of a short would be grounds for rejecting the tube as actually shorted.

Notice that the first picture, you may think that the tube is good because the emission is strong.   

However, the 2nd photo shows that with LIFE TEST engaged, the emission drops to almost nothing.

This is the key to testing ANY tube in a Mighty Mite, but especially for any power tube, thyratron tube, or rectifier tube.