Tube Testers tester

[Findm-Keepm]

It's an dummy tube used to ensure the tester verifies shorts between elements in tubes. As an ex-calibration tech for the Navy, I can say the calibration procedures for testers had you place a decade resistor acrosss pins of several sockets to verify proper short lamp illumination. Someone has just taken this and simplified it, apparently for octal base tubes only. Given most testers have several dozen sockets with varying pinouts, it falls short of completely checking the shorts function.

To fully calibrate a tube tester, we had "standard tubes," shunts, decade resistors, a FET current source, and an RMS voltmeter (to measure incoming line voltage - some use a variac to compensate instead, but measure "average" line voltage rather than RMS as called for.).

TV-7's were easy - it's those blasted TV-2's and cardamatic testers that were a pain. Seventy or more setups for some. Thankfully, they had a three year calibration interval, and were easy to handle on the bench.

Cheers,