Hey all youse 'scope gurus, I'm gonna be getting a new and a used tube amplifier. The new one is on the way and the used one is in my neighbor's garage. He still needs to dig it out so I don't know anything about it except that has tubes in it. If the new one doesn't come with a schematic then right off the bat I want to draw one so I can learn more about vacuum tube audio amp workings. If I have to draw a schematic then I will put in the actual values of the passives as well as the marked values. And I want to measure the voltages in the circuit as well and put them into the schematic. If the old one needs a schematic as well then if I can't find one online I'll need to give it the same treatment as the new one. If I do have schematics then all I will need to do is the measurements and write them down. So.... I have a TEK 465B oscilloscope and it has served me well until now diagnosing my CNC equipment. All the voltages I have needed to measure have been below 50 volts. But looking at the 'scope it seems like at the 10x setting on the probes the highest voltage I can measure is 200 volts. That's 4 divisions at 50 volts per division. And that's peak to peak, not RMS. I do have one 20x TEK probe, a P5120, that I used for measuring the mains power, but the voltages inside tube equipment go much higher. I have been watching YouTube videos about vacuum tube equipmet and have learned a lot so far. "Uncle Doug" has several videos that have taught me a lot. Maybe it's because he used to be a teacher I am learning so much. Anyway, do I need a different 'scope to to measure accurately what is going on inside vacuum tube equipment? Should I just look for different probes with even more attenuation? I certainly don't need the 100 MHz bandwidth that the 465B has for working with audio equipment. If you all think another 'scope should be in my future I would love some advice. Since this is a hobby I don't wanna spend a lot of money on yet another toy, er tool....

200v limit sounds most unlikely. Enjoy frying yourself. It sounds like you will at some point. NT

Maybe I need another 'scope?

Nov 20, 2018 61 Replies

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jurb6006 7 years ago

It was sent at 1:46. I did just notice though that I only used one "R". I j ust now sent it to tabbypurr, so it should be there. In fact I think we hav e had email before because as I put in the other "R" is popped up with a dr opdown below with the address. So it should be there. Lemme know if it ain' t.

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tabbypurr 7 years ago

just now sent it to tabbypurr, so it should be there. In fact I think we h ave had email before because as I put in the other "R" is popped up with a dropdown below with the address. So it should be there. Lemme know if it ai n't.

thanks, got the email now, but no attachment :/ I suspect google stole it.

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