I like the old Mentor Graphics message, "error, too many errors." Then there is the old Electronics Workbench simulator that stated, " The BJT is melting." LT Spice doesn't care, you can jam 50 watts through a TO-92 transistor. It won't complain.
Note, IBM fixed my DUMM BLONDE moment. The released version of OS2 Warp would not let you drag the printer into the shredder.
LT Spice inspires people to make a to-247 part like it though? 🙂
I've never used it to design. I like to test my ideas with real parts... Who else would use a 700V (unloaded, calms down to a reasonable 650V before the board filters LMAO) for a 6F12P and 6SN7 front end?
I use it because it works. Never had a failure (knock wood) in 5 years of 24/7. Same tubes are still fine in the design of the amp 5 years later! Amazing to me really.
The only tube I've used that failed was 6N3P. Vhk was exceeded but every other tube I use in the same circuit worked fine. This took months of 24/7...
I've never used it to design. I like to test my ideas with real parts... Who else would use a 700V (unloaded, calms down to a reasonable 650V before the board filters LMAO) for a 6F12P and 6SN7 front end?
I use it because it works. Never had a failure (knock wood) in 5 years of 24/7. Same tubes are still fine in the design of the amp 5 years later! Amazing to me really.
The only tube I've used that failed was 6N3P. Vhk was exceeded but every other tube I use in the same circuit worked fine. This took months of 24/7...
6SN7 won’t fail at high voltage - 1500 volts peak in vertical amp service. Probably not used for that much after 1950, but they did at one time. They might not like a lot of current up there, but I’m guessing the actual plate voltage comes down a bit from 650 at operating current.
I had a 12SN7 fail h-k, run within rating. The batch might have been used - I don’t really know. Other than the h-k issue it worked fine - with the cathodes directly grounded there is no problem.
George - if you dragged the printer into the shredder, could you reinstall the device driver and bring it back, or was it gone for good unless you reinstalled the OS?
I had a 12SN7 fail h-k, run within rating. The batch might have been used - I don’t really know. Other than the h-k issue it worked fine - with the cathodes directly grounded there is no problem.
George - if you dragged the printer into the shredder, could you reinstall the device driver and bring it back, or was it gone for good unless you reinstalled the OS?
Simulations through the use of LTSpice, here I am much obliged to Mooly, have turned my electronics building from a nightmare to a delightful success. Trial and error using devices like transistors, which require a whole list of parameters to represent analytically, is self torture only fit for being avoided.
To give an example of the complexity of representing transistors satisfactorily, I am posting these parameter lists:
To give an example of the complexity of representing transistors satisfactorily, I am posting these parameter lists:
Code:
.MODEL 2SC5200_k npn IS=300f BF=100 NF=1 BR=8.025 NR=1 ISE=200p IKF=18 NE=2.0 ISC=2.01764E-10 NC=1.5 VAF=400 VAR=100 IKR=1.39087 RB=1.1 RBM=0.00011 IRB=1.51189E-6 RE=0.0032 RC=0.0183 CJE=6.1n VJE=0.711 MJE=0.304 FC=0.5 CJC=380p VJC=0.84 MJC=0.25 TF=5n TR=3.342E-7 XTB=1.72 EG=0.78 XTI=3
.MODEL 2SA1943_k pnp IS=650f BF=100 NF=1 BR=8.805 NR=1 ISE=10p IKF=15 NE=2.0 ISC=2.01764E-10 NC=1.5 VAF=600 VAR=100 IKR=1.39087 RB=1.1 RBM=0.00011 IRB=1.51189n RE=0.0061 RC=0.0103 CJE=5.26n VJE=0.711 MJE=0.304 FC=0.5 CJC=750p VJC=0.84 MJC=0.25 TF=5n TR=3.342E-7 XTB=2.28 EG=0.81 XTI=3
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Well, as Joschl and me stated above, the picture in the 1st contribution to this thread was meant very seriously indeed. It's of German origin, with a German original text, and meant we (the Germans) have well trained professionals to do all the essential jobs, hence nobody needs to engage laymen. Very convincing after a close look at the pic, isn't it?
Best regards!
The 6SN7 couldn't keep up with the ever increasing screen size in 1950's TV sets so the 6BL7 and 6BX7 took the 6SN7's place, often in the same circuit with a few resistor value tweaks and a bigger OPT. Shortly after that someone decided that both triodes didn't need to be big, and the dissimilar dual triode was born.
The Beta version of OS2 Warp connect 3 that I had came on a stack of 1.2 Meg 5 1/4 inch floppies. In the race between IBM and M$ to release OS2 and W-95 M$ played the dirty trick of buying up nearly every 3.5 inch floppy disk on the planet So early versions of OS2 came on 5 1/4's. The fix did involve reinstalling the drivers and some other stuff, but they were scattered across several floppies, and as this was a Beta release, there was very limited documentation. The guy on the phone told me which disk to insert and which file to drag where and all was good. Without that help, it would have involved a complete OS reinstall.
I have come to realize today that completely reinstalling Windows, often on a new boot SSD is the easiest way to fix random weird stuff that comes up, often right after a M$ update.
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I had 5.25 floppies with my Commodore 64C. There was a game called Drive Test or the like, that come in two of them, one with the main progran and the second with the scenarios. At the starting of the game you need to run the program in the 1541 floppy drive, and each time you advance to next scenario, you need to swap the diskettes. But the game was very funny.
We had an Apple II in the cal lab at work in the late 70's. I worked night shift, so after all the bosses went home, we broke out the Castle Wolfenstein disks. The game ran from a single diskette, so this allowed for lots of cheating if you kept a few copies of the disk. The game kept track of your progress through the castle by writing on the disk. If you got killed you just had to be quicker on the disk drive door than Apple was at writing to it. Start over and you are right back where you were but still alive.
Tech support calls are useful. Many years ago I read of someone who'd called in because their scanner didn't work. Turned out they were holding the document up to the monitor. But, honestly, how would you expect it to work? Now we've got cameras in monitors and phones we can scan documents like that...
On many occasions they are hilarious.
PC vendor company I worked for had a call to service department over minor issue. Once it was resolved, customer said:
“That coffee cup holder at my new PC is fantastic idea.”
Huh, what?
"You know, that top slot at PC where you push a button and tray extends out."
🤣 It was a new invention, CD-ROM drive.
Another legendary one was when a company called, just before Christmas, that their server stopped to work. It was determined on site, that ladies from the office pulled the plug out to plug in Christmas tree lights.
That's rather sad if the photos were produced to promote tech work. No one caught the glaring mistake? How many people saw it before it was published?
I used to work with a man who duplicated video tapes. Much of his work was making copies of commercials to distribute to television stations. He would catch a lot of typos, spelling errors and so on in the adverts. One I especially remember was for a tech school - a young man who had graduated saying the the training "Turned my life around 360 degrees." No one had caught it, only my buddy who made the tape copies. That commercial spot was reshot and edited in a hurry to say "It turned my life around 180 degrees." Strange how such glaring mistakes can make it so far thru the production process.
Some years ago a German radio station comedian did a survey asking: Should marriage be allowed for heterosexuals? You won't believe how many of those folks got upset upon this »strange« thought 😉!
Best regards!
Best regards!
Another similar survey in the past years: Do you think Angela Merkel is corpulent enough for being the German chancellor? I think you know the peoples' reactions 😛!
Best regards!
Best regards!
Back in another life, when I worked for RedHat, our version of that was to create a file on the machine called
/etc/id10t
Nigel, you should be giving this nice lady some soldering lessons, don't you think? With your experience.