08-23-2014, 10:37 AM
I use a Simpson 305 tube tester for most of my testing of tubes, and an EICO 628 for more modern tubes.. The circuit in the Simpson is very simple and it is very well built. All I had to do on mine was replace the line cord and the single condenser in it and it works like new. It is very accurate repeatable in its evaluations. You find them on eBay every now and then.
