Tube tester

[Hydrolastic]

Hello guys. Purchased a new to me tube tester B&K dyna jet 707 . Been having fun doing the testing. one of the problems with buying stuff like this is you may have to refurbish it before you can use it. I purchased this one because the guy said he had gone through it completely and did a transistor replacement of the "problem tube" these units have. Only found one bad tube in the stereo's but only about half done. I noticed on one of the tubes that it reads bad but I then tested several of the same ones and they have the exact same reading so I think my book settings is wrong.?. Still its been fun. Here is a photo

[William]

With all of those sockets it looks like it would test every tube known to mankind. Nice find!

Bill

[TC Chris]

And bear in mind that some tubes that test badly will work just fine in-circuit. I usually look mostly for shorts and leakage.

Chris Campbell

[Hydrolastic]

Hello Chris, what do you mean by leakage ?

[electra225]

I have a 707. The "problem tube" with them is a 12AX7. I don't like the way this tester tests for shorts, otherwise, I like it. Output tubes should be professionally matched for best performance, particularly in a Magnavox bi-amp.

[TC Chris]

Hello Chris, what do you mean by leakage ?

The straight answer is "I dunno." It's a test on my testers. I always assumed it was a gassy tube.

My testers are emissions testers, not transconductance devices, so unless the quality (total emissions) is down at ankle level, I assume a tube is good enough if it has a functioning filament/heater and no shorts.

Chris Campbell

[Hydrolastic]

ok looked up the unit here is what he said.... "The important solid state rectifier modification was done making the tester much more consistent and eliminating the need for that big #83 rectifier tube that keeps the unit hot all the time."