Great article from thetubestore.com, How To Tell If Your Tube Is Bad ...

[joeinid]

http://blog.thetubestore.com/how-to-tell-if-your-tube-is-bad/

 

[mep]

This reads like a "Mr. Obvious" article or a "Tubes For Dummies" article.

 

[joeinid]

So you did learn a few new things, great.

This reads like a "Mr. Obvious" article or a "Tubes For Dummies" article.

 

[jdandy]

Joe.......This is how I test my tubes. No guessing required.

 

[joeinid]

That's cool Dan. I ordered an Amplitrex, mainly because I can test 845's and 211's. Now if I just just figure it out , actually it's not too bad. I just need to set it up and test some tubes that I have laying around for practice.

 

[jdandy]

Joe.......The Amplitrex AT1000 is a fine tube tester.

I test my preamplifier and power amplifier tubes annually and maintain a spreadsheet on the readings. I am not really concerned with tube hours. Comparing a service tube to a new one tells me what I can expect. I pay particular attention to my KT88 power tubes' plate current and transconductance. If a power tube begins to measure weak, I will replace it before it fails.