Tronola article on a new, high-end, vacuum tube analyzer project

slafferty

slafferty

New Member
Tronola.com has just published an article covering a new vacuum tube analyzer design. This culminates a seven-year project to produce a tester such as the legendary instrument maker, HP (now Keysight), might have built. Full documentation is provided but could a hobbyist build it? Mostly analog, with no uC and no SMDs (except for a small kludge). http://www.tronola.com/html/vacuum_tube_analyzer_page1.html

Comments are welcome!

Happy Holidays,
Steve Lafferty
http://www.tronola.com/

VTA_side_view_400.jpg
 
I have to say, you've done a very impressive job in designing and building this. Thats a lot of work, and a whole lot of wiring inside. It also looks very finished on the outside, which I can really appreciate. Very cool indeed.
 
I really appreciate your kind words, Gadget. The application process of the front panel art is covered in the gallery with slides 15-17. The next 9 or so slides show the machining. Regarding wiring, slides 33-35 show interesting views. At one point, all of the socket wiring had to be removed and that little fiasco is seen in a trio at slide 44. http://www.tronola.com/vtagallery/vtagallery.htm
 
Very nicely done! Though I think HP would've used LEDs or nixie tubes for the digital displays, of course. ;) Also might benefit from some older-style knobs on the front panel, but overall it definitely looks like something HP might've come up with back in the day. Definitely looks like a worthwhile project, if more than a bit more complicated to build and use than the average Heathkit or Eico tube tester would've been. Of course, I'm sure it does a lot more as well. :thumbsup:
-Adam
 
Many thanks, Adam. Yeah, my shot at making it "like HP might have done" was mostly in terms of accuracy, range and flexibility. I did go to some trouble to get the front panel color "right" but the styling didn't go much beyond that. Actually, the knobs (excluding the five voltage controls) are a little nod to Eico. They're kind of close to my heart, since I built their test instruments as a kid :)
 
Had a chance to go through the slides. Wow, you really did go all in on this. Custom winding springs and modding detent slots to get just the right switch feel is definitely beyond where most would tap out.
 
whoa SteveL, you really outdid yourself with this. Are you taking orders? It is always interesting and educational products coming from your workshop. Happy Holidays
 
The VTA stands in relation to other tube testers as a modern smart phone stands in relation to two orange-juice cans connected by twine.

It journeys far beyond the lands of mere test equipment made by mortals; it climbs the mountains of technical excellence and enters the rarefied realm of high art to which many aspire, but few attain.

Outstanding work. Simply astounding.

I wish I had the time and cash to construct one.
 
Gee, you folks are kind. The comments are so very heart warming.

Gadget73 -- I'm so pleased that you enjoyed the gallery. Yeah, I guess the rotary switch modifications could be evidence to have me committed. Yet, the Electroswitch C4 series rotaries are the best affordable (but not certainly not cheap) rotaries I've found, except for the fact that they're hard to turn. For pin settings on a tube tester, that's a serious flaw. Of course, that's an irresistible challenge for an engineer/hobbyist :)

S-petersen -- Thank you for posting about your RCA WT-100A tester! From the documentation I've found, it was indeed an excellent tube analyzer in its day, with a regulated power supply and Gm AC grid voltage as low as 5mVrms, it could measure as high as 100,000umho. Do I hear someone say, "Who needs that?" Well, I ended up adding an extra auto-range circuit because I found that the original 20,000 limit wasn't enough. (Ref slides 44,45 in the gallery.)

Primosounds -- Many thanks! I so wish I could produce this as a kit or something. The thing is, it would need a new PCB layout to accommodate all the mods. Alas, having put seven years into it, I must do some other things before I go off to that great electronics lab in the sky...

Retrovert -- (blush) I really appreciate your encouragement, so eloquently said. Love your signature line! <har>

Steve
 
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Steve ,
Really nice!
Looking on my phone now.
I'll have revisit on the computer and see what this really is.
 
Steve,

Your work is absolutely first rate. I designed and scratch built a variable bench power supply last year that I thought was complicated! Mine only took three years! Nothing doing as compared to your work here. But I do have appreciation and a small understanding of the complexity and tenacity you must have gone through to get this complete and working. Your workmanship and design skill is really something to aspire to. Great, great work.
 
It's so nice of you fine folks to respond.

Scott -- Many thanks for your kind comments about the website. I should point out that Dave Gillespie and Arthur Grannell have authored excellent contributions there, too. Moreover, Arthur reviewed the present article in great detail and made many valuable suggestions for improvements, as acknowledged at the end of the article.

Kward -- Thank you so much for the nice compliments. Congratulations on hanging in there and perfecting your power supply! Designing and building a good laboratory power supply can be a tough challenge. Too often we take power supplies for granted. They're actually DC-coupled power amplifiers with demanding stability requirements (in constant current and voltage modes) under a wide range of loads. Cheers for designing and building your own!

Steve
 
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Steve it heartens me to see a project like this and your dedication to detail.
Well done sir.
 
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