[R-390] Tube testers TV2 Tek 576 curve tracer

[Glenn Scott via R-390]

Steve,


you asked.



> I use the TV2 for more thorough design work in conjunction with my Tektronix Curve tracer.

How do you do that, since the TV-2 reads transconductance in "percent quality"? Have you calibrated the shunt control? If so, how? Have you added plate current metering test points?

Best regards,
-Steve
______________________________________________________
That bench for my tube work is very involved with HP low and High power DC and AC supplies, A Tektronix 576 curve tracer, TV 2 tester with a proprietary interface between the TV 2, Tek 576 and fixtures/interfaces. I use an HP 3580 spectrum analyzer for base band signals and an 8566B spectrum analyzer for signal interest to the GHz range, should I ever have the need. Additionally there are several counters, sig gens converging to test fixtures with proprietary interfaces/cabling between the various test apparatus. 
There was an excellent article in Vacuum Tube magazine about 2 or 3 years ago about using a TeK 576 curve tracer with tubes and this spurred my interest in eventually taking all of this several steps further. At least one audio tube vendor has videos on youtube demonstrating tube matching with a Tek 576 curve tracer. The 576 was designed for SS devices but it didn't take much work to use it as an excellent tube equivalent. 
https://www.youtube.com/watch?v=ayLjvgcyfTc  
I did not infer any kind of direct connect between my TV 7 and curve tracer, However, rest assured everything that I need for looking at various distortions and noise with regard to variations in plate voltage and grid/screen bias(s) of the tubes of interest at specific frequency ranges is available with this somewhat elaborate set up..  
I did my mods on the TV2 so they can be reversed without any new holes. The  TV2 proved to present many challenges and as sophisticated as it looks it seems to have been poorly or partially  thought out. IMO.  I may work it out of the test setup soon since other processes I have in place are proving to be much more adequate. 
Actually, most tube testers are deficient with regard to a number of parameters. As I said in my post, I use the TV7 as a go/no go indicator and to get a general sense of the tube quality and if it MIGHT work well in a specific application. I have tested tubes in numerous tube testers as good and in real applications they proved micro-phonic, noisy, or lacking gain at higher freqs. However, most of the time if I test a tube as good with a standard tube tester, it does fine.
73,
Glenn Scott WA4AOS
DSM Labs   (dot com)