I'm afraid that transposition will lead to mechanical stress to both wires, due to the force applied to them by the layers on top. And these forces *imho* are larger at the corners than between them.
This winding advice, along with similar ones in other Bereskin papers, will keep a mystery to me...
Best regards!
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one thing is for sure, this will be a tough wind for me since
i use manual rewinding machine....
there is another type by Alvin Lockhart, it used C cores...http://www.tubebooks.org/Books/lockhart.pdf
One thing is for sure: If I'd walk into a winding shop and ask the staff to do it this way, they'd throw things after me 🙂.
Best regards!
Notice that the 3kW transformer suggested is expected to pass the 400-5000 Hz range.
Probably the amplifier for a racetrack PA system or similar duty, driving 200 reentrant horns, distributed all over the place.
Probably the amplifier for a racetrack PA system or similar duty, driving 200 reentrant horns, distributed all over the place.
We don't know what this thread is about. The OP has made one post, and the only supply mentioned is 3KV at 1 Amp. He talks about an input power supply and an output power supply, and mentions 2 different types of forced air ceramic transmitting tubes.
I for one can not envision this combination being used in one amp. 3KV is too much voltage for the 4CX250 series tubes (2 KV max) and 3KV at one amp (3KW of DC) is good for 1500 to 1800 watts of audio. The 4CX1000's are good for just over 3KW of audio from 3KV but about 2 amps of current and a 3860 ohm OPT are needed. If 1800 watts is sufficient, then only 2KV is needed for 4CX1000's. The OPT would then be 2,040 ohms, which might be possible.
The logical assumption that can be drawn from the OP is that the 2CX250's are the "input stage" and the 4CX1000's are the "output stage", needing a bigger, as yet undesigned "output power supply." You don't need 600 watts of driving power to feed the 4CX1000's. They are not specified for AB2, and max G1 dissipation is ZERO. 3 KW of output needs about 120 V P-P of drive voltage. You could drive them with a 6SN7!
Either way, an amp of this caliber has a very low probability of first time success, even when attempted by a seasoned builder. I mentioned the 600 volt 300 to 500 watt range, because that is about the limit of my comfort / budget zone. It is still beyond what I would expect from someone who is "out of practice."
The cost / probability of success curve takes its first upward bend in the 50 to 70 WPC range (400+ volts), and starts going logarithmic over 200 watts. A fat budget can mitigate the cost factor, but when something goes wrong at 3KV, experience is what keeps you alive, and your house from burning down.
I built a 1200 watt RF amplifier when I was about 25 years old. It ran on 3800 volts, and scared the $#!# out of me every time I fired it up. I wound up giving it away to somebody who rebuilt it in a more sane manner. He was the engineer at a radio station.
Anatoly, what are the specs for those switcher PC boards? I don't see them on Ebay.
One can get Lambda 500W or 1000 Watt PFC input modules cheap off Epay, 360V out, but not isolated. (pic below)
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"you have clocked his user name?"
I see 1 post per month.
Isn't that about how often Alzheimer's relapses? (OK, sorry-sorry, just making a funny statement. So building a 3 KV power supply ehh. )
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One can get Lambda 500W or 1000 Watt PFC input modules cheap off Epay, 360V out, but not isolated. (pic below)
-------
"you have clocked his user name?"
I see 1 post per month.
Isn't that about how often Alzheimer's relapses? (OK, sorry-sorry, just making a funny statement. So building a 3 KV power supply ehh. )
..
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......cermet "tubes" are not eyecandy, but have high steepness.😀
https://frank.pocnet.net/sheets/140/8/8168.pdf
If you could Schade it, to µ~30, it will have ra800. Hmm, lots of possibilities as 300B "replacement" or even spud >µ100
https://frank.pocnet.net/sheets/140/8/8168.pdf
If you could Schade it, to µ~30, it will have ra800. Hmm, lots of possibilities as 300B "replacement" or even spud >µ100
Yes, and I looked at some of his other posts. We can all take guesses, and make comments, but some more information from him would let us know what he has in mind, and how to point him in the right direction.
I for one would like to see some more really big amps, but it's no fun to follow a long thread to reach a pile of burnt parts in the end....or worse.
Hence my remark about driving them with 6SN7's. It really would be possible.
I once got the idea to build a big A$$ guitar amp using 4CX250B's (7203). My plan was to drive them with 12BY7's, because I had several.
I set out to build a ham radio linear amplifier for 144 MHz with a pair of 2CX250B's on 1200 volts, maybe 20 years ago. Before that was finished I got a hand full of MRF150 mosfets and built a solid state linear amp. Since I had the power supply, several 4CX250b's and a pair of 4CX350B's, I got this idea to make a killer guitar amp using a repurposed power transformer for an OPT. Before that happened, I sold my unfinished RF amp and all the tubes to the guy who got me the MRF150's. We both worked for Motorola at the time.
500W Amplifier Switching Power Supply Board Dual-voltage PSU +/-55V | eBay
Sure AA-AB32291 2x250W IRS2092 Class-D Amplifier Board | eBay
It is a copy of IR sample design, but using SMD components.
https://www.facebook.com/Wavebourn/videos/1456687211056242/
Yes we do. It's about those big Plitrons you keep mentioning. The data pages make them look awesome. I've been using their wee sibs, the VDV-8020, for a couple of years now and love them. Yours are rated for 20 times more power with twice the inductance. I like those ottoman chairs that vibrate.
This thread started it over 10 years ago. Plitron put some of the 400 watt toroidal OPT's up on their surplus transformers page for $134 USD each. I got a pair as did several other people reading that thread. When I got my pair and saw how big they were I thought about getting a second set....but they were all gone. I talked to a technical guy at Plitron and it seems that all of these were variations of the same HiFi OPT that were made up for a "big name British guitar amp maker." They were not all the same.
http://www.diyaudio.com/forums/tubes-valves/100852-eight-807s-push-pull.html?highlight=807+plitron
I have used my pair for dozens of experiments, test amps and other high powered experiments. They are rated for 1250 ohms to 0,2,4, and 8 ohms and as the label says "400 W RMS @20 Hz." There is enough inductance for them to work fine at 2500 ohms and 5000 ohms. I have seen 525 watts flow through one of these transformers from 4 X 35LR6 sweep tubes on 650 volts at 1.5 amps. I used one of Pete's big red boards with both channels wired in parallel through a single OPT. The board made 504 watts @ 5% distortion, and 525 watts at the onset of clipping.
Last year another forum member put his pair of similar Plitrons up for sale in the swap meet forum so I grabbed them. They are potted, and nearly twice as big as my pair!
In another random crazy purchase I just grabbed a large 4U rack mount computer chassis for real cheap. I doubt that a complete stereo monster amp could be built into one of these, but it could probably handle the power supply for a stereo amp, the stereo amp sans power supply, or a mono 500 watt amp. I am hoping that they will still be on sale when the chassis arrives. I might have to get a second one. A suitable chassis in one of the missing elements that have prevented me starting down this road. Tubelab's budget for 2017 is essentially zero, otherwise I would use a custom Landfall chassis.
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> Probably the amplifier for a racetrack PA system
I would bet that Prof Bereskin was asked to design for the college football stadium. For sanity it would be about fifty 60W horns like your picture.
I would bet that Prof Bereskin was asked to design for the college football stadium. For sanity it would be about fifty 60W horns like your picture.