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Data Sheets

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.... and you can prove all this ?

Well, I have a test rig running on my bench, even now as we speak, and
I'm not hearing the tube complaining....
Again, the tube is not solid state. The tube is a mechanical device, and I just don't think it cares................

I think the data sheets are written more as application notes, rather than absolute max limits....
If I had the time, I would really burn this tube up, but I don't, and as mentioned before, I not get anything for it........

-g


Sample size of one out of a run of one is not much to base a data sheet on.:eek:
 
You only own 1 tube and presume to know it better than than the manufacturer? And on top of that you were the 1st to LED bias a tube?

1. I've been building guitar and HiFi amplifiers going back 12 years. I was ET in the US Navy, going back 45 years. I have one HiFi stereo amplifier, Surface 2, does not even use a pre-amp to drive the power tubes.

2. I was first to publish lamp biasing on ValveJunior.com, abouts 12 years ago. Then I noticed the Valve Lizard out of the UK publish on his website a bias diode shunted by an electrolytic cap. Was so funny I took a screen shot of it.

3. ...... and that would be Dr. Moore to you......
 
1. I've been building guitar and HiFi amplifiers going back 12 years. I was ET in the US Navy, going back 45 years. I have one HiFi stereo amplifier, Surface 2, does not even use a pre-amp to drive the power tubes.

2. I was first to publish lamp biasing on ValveJunior.com, abouts 12 years ago. Then I noticed the Valve Lizard out of the UK publish on his website a bias diode shunted by an electrolytic cap. Was so funny I took a screen shot of it.

3. ...... and that would be Dr. Moore to you......

Wow, what qualifications! THE ValveJunior.com! Not THE ValveJunior.com? The forum devoted to a disposable tube practice amp? Was it hosted on a 486?

If you do manage to stick around here now that the 486 failed you'll see why qualifications don't always mean much to us.
 
I am wondering, who would it be, for me to talk to, to update some of these spec's in tube data sheets...?

I don't know who you would talk to.....or if anyone would listen. The specs in question were written long ago by people who are no longer alive, and if they are, could care less about vacuum tubes. Say you could make up a data sheet for a tube that had different numbers that those published by the company that actually designed the part, and made it, what would lead anyone to trust someone who says that based on a single example that those 50 year old specs are wrong?

Based on a single example, I can say that my TSE amp has a 5AR4 tube happily feeding a 100 uF cap. That amp has had the same 50 year old Sylvania made RCA tube in it since it was built 16 years ago, it works reliably, and has never faulted. Experience tells me that stuffing a batch of new production tubes in that same socket will result in at least 10% of them failing the first time the power switch gets flipped.

Based on a single sample, I could be in the parking lot at work on a rainy Florida day, stick the gas pedal to the floor in my car, and repeatedly slam the shifter between drive and reverse while spinning donuts all over the lot. It never broke, and I had that car for several years. Would all 1970 Plymouth Valiants respond the same way? NO, I'm pretty sure that most would suffer some busted parts......there are several variables here. In this case it was the crappy tires, underpowered engine and light vehicle weight. In your case you might have a power transformer with high DCR, a tube with slightly low emission, or a high ESR cap.

Tubes are indeed mechanical devices that were assembled by humans. No two are exactly alike.

Get a rectifier tube with a perfectly round cathode, properly centered in a perfectly round plate, with a perfectly even uniform coating on the cathode, and it may indeed survive maybe 1000 uF, forever.

Get one assembled late Friday afternoon near "quittin time" or on a Monday morning after a party weekend, and all of that start up current will flow at the point on the cathode where the coating is the thinnest because it heats up the quickest, and if that happens to be a bit closer to the plate because the alignment is a bit off, sparks will fly, and tubes will die. Been there, blown that!

41 years as a product development engineer at Motorola, most of that on "mission critical equipment" (people could die if it doesn't work) has taught me to design to a very conservative spec on incoming parts.

Change all the specs you want, I'll stick with the ones I trust.....and verify what I don't.

I spent nearly two days curve tracing some 6KT6 tubes. I have found 7 different variants of that relatively obscure TV tube. No two of them are alike, and only the 50 year old RCA tube comes close to the 1966 RCA data sheet. I will make sure that all will work in my design.

I'm sure that there are a lot of things called "EZ81" or "6CA4." Some will naturally be stronger than others, but a good designer MUST design to the weakest one, because someone somewhere will stick one in his amp, and crank it to ELEVEN.

Do what you want with your own personal amp, but if you build amps for sale, someone somewhere will find a way to blow it up. Your job as an amp designer is to make their task harder.
 
Seriously?? You probably need to contact a psychic who can perform a seance. The engineers who designed the tubes and came up with these specs are long dead. And they didn't just pull the data sheet specs out of a hat. They are the result of extensive testing.




Ive been looking on Amazon for a Ouija board. But most of these are made by the Chinese.. I have some questions regarding the best practices.


Edit nevermind, appearantly all the information is out there.


How to Use a Ouija Board | Psychic Abilities - YouTube
 
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I put customer lists on an HP71B handheld running in BASIC. And got the HP2225A inkjet printer for it. Also the HP9114 disc drive & a compatible CRT display. And some 3rd party extra memory to load it up. And the interface board to a PC. Still have all here in the pile & another HP71B given by a former HP employee.:)
There was a whole line of products that interconnected on the HPIL Loop. The command set for that a lot like the HPIB that became IEEE488 / IEC625
 
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