[R-390] Tube Tester

[Perry Sandeen via R-390]

List,


 
Tube testers are getting scarce and more expensive.  Added to that fact are the calibration, age andcondition issues.


 
I have reproduced an article: rec.audio.tubes tubetester project, by Steve Bench and added some revision changes. The original isstill posted on the net.


 
This is as modern of a unit that you can get. Hetests the 3 fundamental Vacuum Tube (Valve) constants. These aretransconductance (gm), plate resistance (rp) and mu.


 
This unit can be made for less than $100 in partsand uses good old through-the-hole parts, no microprocessors, and no programingrequired.


 
It can be built by anyone with a modest level ofskill.


 
All I have done is reproduce the schematic as an 8bit image and design a simpler filament circuit.


 
While geared for the audio folks, it does test allthe B/A tubes we use.


 
If interested, please send me an ORIGINAL emailOFF list and I will email you the article.


 
Regards,


 
Perrier