What’s on *YOUR* workbench?

PunchySunshine said:
They aren't cheap...at all, but I got a couple of strings of these for the tree this year as I got tired of the same game you've been playing. Every time I would look at the tree this year it made me VERY happy! I may pick up more for the outside decor next year. You've got to keep checking back as they are usually sold out.
Tru-Tone
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You could also hit up the VAST assortment of Tayda Christmas lights! :ROFLMAO:

Search results for: 'christmas'

www.taydaelectronics.com www.taydaelectronics.com
 
Every now and then I get one of those "I'm not sleeping until I figure this out" ideas, and it's now 5:30AM. But I made a rudimentary Arduino-powered tube tester.

I was ordering tubes and I realized they don't offer burn-in for preamp tubes like they do for power tubes, but most of the failures I see happen within the first 24 hours of tube life, so I was thinking about designing a burn-in station for my preamp tubes so I can weed out the bad ones early. As I was thinking about what it would look like, I was thinking how neat it would be if I could add a signal generator to the each triode and then measure each output to easily check how each one is handling over time.

The Arduino is generating a signal (basically a square wave, I gave up on trying to get a sine wave out of it) that feeds the tube, then it monitors it through the ADC input and compares it against a threshold I set in the code to determine pass/fail. I added a timer at the bottom so I can verify how long each one has been running. I only have one triode hooked up right now, which is why triode 2 is reporting a failure.

06fd7bf9-d55c-4f09-8ff8-7f31d07467aa.jpg
 
Currently on my workbench . . . . three "Two Sticks of Derm" one completely stock and the other two with Germanium BJTs.
I tried a few different Silicon jellybean (2N5088, 2N2222 & 2N5133s) and they all sounded great!

The I futzed with some NOS Germanium NPN BJTs. With R2 & R6 replaced with 100K trimpots, I slipped in two NOS Ge NPN NTE103A (2SK3835) BJTs (hfe @ ~200) at Q1 & Q2 with a NOS Ge Mullard CV7112 (OC140) at Q3. At first it was very gated, but then I turned the trimpot at R2 down to ~8K2, (setting the trimpot at R6 at ~33K), and it came to life beautifully! I noticed that with the Ge BJTs, the attack transient is much sharper and extremely defined - adding a nice nuance to the fuzz. I'm considering replacing the two 4K7 resistors at R4 & R7 with trimpots to see how well the "Fuzz" aspect can be controlled.

2SticksOfDerm_02_Populated_01_Si.jpg 2SticksOfDerm_01_Test2.jpg 2SticksOfDerm_02_Populated_01_Ge.jpeg
 
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