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39:27 - the voltage divider feedback resistor is going to be hundreds of megohms IMO, and because that is such a high impedance it could easily pick up stray EM fields - that is why it has that copper wrapping surrounding it, to limit how much of the stray fields are picked up.
When he said only 3 companies make that class of oscilloscope, which 2 other companies do you think he was referring to? Surely he omitted the qualifier "domestic", meaning USA-based? If so, clearly the other two would've been Tektronix and Agilent (Keysight). But worldwide I'd think also Rohde & Schwarz? Or maybe Tektronix doesn't offer such broadband scopes?
Extremely cool! I'm working with a particular TREK-built power supply for a particular application, and they are very neat and tidy inside, my eyes lit up when you showed the back of the unit. My supply is only a mere +/-2kv, but was still very impressed with the construction, very similar to this. They got the entire PSU into a 2U rack unit. Awesome! Didn't mention that mine is six phase output tho ;)
The high q of these devices makes them suitable for conversion to a resonance cavity for measuring the dielectric constants of materials. It feels sad destroying a piece of finely machined history, but the new resonance cavity measurement devices sometimes cost 5-10K and one can make a reasonable measurement device for under $50 using this method.
One thing I was wondering is how the individual sections are balanced? Obviously, as they are driven, they won’t match perfectly so some sections will develop a different voltage to others. Do they rely on local breakdown using a Zenner action of power FETs? Or are they somehow, actively balanced all the time?
Where I got my education, we did some HV lab tests and some more were just shown demonstrations. The “volt meter” was a couple of polished 2 ft diameter metal spheres as a spark gap. besides the air gap, we needed air prssure and humidity data for correction of our result. I still recall a couple of memorable equipment in the lab. One was a MECHANICAL rectifier, an about 6 ft diameter disk rotated by a synchronous motor. There were contacts at the disk perimeter, and other contacts near the disk, outside, maybe leaving a 1/8” gap. If I recall, we got about 200 kV DC with it. Mighty sparking in operation! Another device was a little more “modern” device, hybrid Greinacher-Villard voltage multiplier that had a number of series connected ceramic capacitors and matching number of spark gaps. Finally, in actually in a different lab I saw a voltage divider built with a 20 or 30 ft long polyethylene tube, filled with ion exchange purified water. I was told it could be used to over 500 kV as the upper resistor of the voltage divider.
Hi. Could you make a video on mobile phone RF side? Infrastructure. For example in a very crowded city with 1000's of people using their phones simultaneously, you would need that many channels on separate frequencies. What amount of bandwidth would that require. How it is done in real life? Thank you.
I have 2 of the smaller and older TREK610C amplifiers. They use the same style voltage dividers as Yours, I have wondered how that is built, to expensive to take apart though... One trade name of these was coratrol, I do not know which part it refers to. These were very expensive back then, over 10000$ for the 610C if I remember correctly, still work fine. These use vacuum tubes, the somewhat later 601D was solid state, same specs. TREK s really good quality.
Great video. You are so brave! I have a tesla coil that can make 6 inch sparks. I only run it in a room with none of my other equipment - no oscilloscopes, computers, etc. I keep at least 3 feet away from it - the thing scares me!
Great video, thanks! This thing samples so fast, that you can used as a low speed oscilloscope, or spectrum analyzer. You can digitalize an audio signal, perform an FFT on the raw data, and compute distortion!
I have a 5071B Option 214 (2 ports) and have been using it for years. After I changed the motherboard system battery, the VNA booted with the wrong option, 413 (4 ports). Is there a way to revert it back to option 214 (2 ports).
Wow Shahriar this video was fantastic. I have a YT channel as well. Now I don't have a fraction of the knowledge you possess in this field, but I've tried to learn electronics myself via repair/teardown of equipment. I just did a video (link here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VbjpNxxFwTo.html) shortly before you released this one on a teardown of Trek 610E which isn't as beefy as the one you shared here, but can provide up to 10kV at 0.2mA and amplify 1000V/V. You answered a few questions I had in my vid about the circuitry. 1) My Trek also had one of those long shielded cylinders which I thought was some kind of current monitoring device. Thank you for clarifying that it is part of the feedback circuitry. You can actually open it up as it has screws on the top and bottom! 2) The Trek 610E uses two 6BK4C voltage regulator tubes. One for positive voltages and one for negative. Very different than the 20kV supply you had there. 3) I can also see the light pipes being used as optocouplers on the voltage regulator tube modules on the 610E. Though I was not astute enough to know what they were at the time! 4) Question: On the 610E the main PSU outputs a 800Vpp square wave (I measured it with a HVD probe). That AC HV voltage then goes to an HV multiplier and then off to the 6BK4C tube modules. So at what point is that signal rectified and smoothed out for a straight DC signal? Thank you again for this amazing video! I really learned a lot. I love how you covered so many different equipment types and how they work in less than an hour!
I think your static arc may be related to the acoustic cavity resonance of the tube, judging from the behaviour of only stopping at very precise frequencies. If anyone knows more than me about the acoustics of plasma arcs, do chime in!
A superb video - a very rare insight into high voltage electronics. I can’t imagine what the engineering challenges are like in +\-800kV DC power line distribution systems they’re using in China where they use inverters to convert back to AC.
that amp is straight up and down nightmare fuel. im a great believer in "with great power comes great responsibility" when setting up equipment but that amplifier due to its nature seems so unforgiving. the kind of equipemnt you want to be sure all input voltages are on the money then you power this thing up. you certainly wouldn't power it up first.
Fascinating. A beautiful instrument. I would love to see the schematic for the stacked high voltage stages to see how the biasing is achieved and protecting the devices from overvoltage. I have an equally lethal vintage power supply. 17kV DC from a mains transformer and what looks like stacked selenium rectifiers then a large "Visconol" smoothing capacitor. It has no problem pumping out 30mA on a short circuit. To be treated with great respect.
At work we have a soft start that is feeding a 3400HP motor powered by 4160Vac. The SCR stack has much the same sort of arangement with individual boards driven optically by the trigger board. This thing is on a whole other level though. Easy to understand why the amp cost $70,000.00 USD. It is clearly not a trivial mater to engineer and make such an instrument. Great video as usual!
