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I have a question since I know very little about tube circuits. I bought this device off an estate sale, it has two OD3A tubes, a very large Mallory cap and a giant transformer with lots of secondary outputs. The front of the chassis has one pot and the rear has an eight pin tube socket. Is this thing a power supply ? I looked inside and it not only looks homemade, but it's pretty clean. I just dont know tubes enough to make an educated guess. Oh, I probed the eight pin socket and I found- adjustable 250 vdc to just over 450 vdc, a steady 350 vdc, and the common filament voltages. Any idea ? Thank you.
I haven recently become a Patreon to further your cause which is informing (and trough that, entertaining :-) ) all of us tech-curious people who are connected and brought together by your excellent video's, projects and knowlage in general. Everytime a new video appears on your channel I am sure it's going to be well worth watching. And I am sure that I will learn something new everytime. Awesome :D Thanks a million times and keep on teaching, Mr Carlson ! "Diodes have Jumper-envy" You see? :D Yea, yet another thing learned today ! Greetings Raoul, The Netherlands
I learned a lot on this restoration. Yours, and mine. I did not need dropping resistors after replacing the selenium rectifiers. The voltage was actually a hair below 270 volts. Also, I could not zero the voltage. The 680K resistor after the CWA pot measured 780k! I tested the circuit and determined a lower resistor was needed to allow me to zero the output. 680k was still too high. A 560K resistor put the CWA pot right in the middle of travel when the voltage was zeroed. Perfect. I’m very pleased with the supply and the great learning experiences. Thanks for the help.
Rarely I can finish a movie or show or any type of related programs, regardless of having many sources to entertain my self, your videos are really easy to watch, learn new things and enjoy every moment of.
Man does that bring back memories. Graduated from tech school in 1963 many of my friends went to work for heathkit in Benton harbor Michigan. 7 years after I graduated my education was outdated because of semiconductors. Thanks mr Carlson for the presentation did a fabulous job on chalk talk through the schematic need a lot of this when servicing circuit board schematics keep up the good work this is Wb8idy in Swansboro nc very very well done from brian
Another excellent teaching video! I am proud to support you on Patreon! If I have any complaint at all, I can watch the video in the run time, in this case, 58.42 minutes with the result of WANTING MORE LOL! I have made a few videos and know just HOW MUCH time it takes to film, edit and produce a video so I understand the time factor! Again, thank you for the huge effort it takes to produce these for us!
I am a huge fan of the two tone gray heathkit equipment. And I really enjoy Mr. Carlson's videos! I have a great deal of appreciation for experts who are willing to help the beginners. That says a lot about someone's knowledge, but much more about their character!
Heath kit was still popular in the tech community when I was growing up in the 70s. I sure miss them. Reading their catalogs was so fun to a wannabe young techie. My maternal grandpa got me hooked real good.
They still sell a couple of items, nothing really interesting. I was looking at a catalogue from the late 1950's. The average American must have been earning damn good money back then, because most of the prices were way beyond what average folks elsewhere could afford.
@@Frankowillo So true. Many Heathkits are still beyond the reach of the average person because I continually see eBay scalpers advertising so-called "restorations" of old kits and on-selling them at ludicrous prices beyond what reality should dictate. If vintage fanboy Hipsters keep paying these high prices and keep turning good test gear into bedside lamps, they'll keep driving up demand, therefore price. Heathkit gear is nostalgic, but in many cases is still necessary especially for testing tube gear (such as tube oscilloscopes that can handle high voltage when fixing radios and Amps) unlike many modern digital test devices that will get blown out if any HV touches them (requiring work-arounds).
I, as a young lad once surprised myself with a cheap broken camera. The flash unit cap was charged and upon touching it, I threw it to the opposing wall and jumped back a good length too. When I went to inspect, it still held about 300V. Didn't expect that from a device that took 3 AA batteries, but I got wiser quick.
A new ham of 3 yrs. Many years in minor to some moderate electronic repairs of sorts and always trying to learn. Great explanations. I am just learning vacuum tube technology and having a blast. I am so glad I have come across your channel. The way you explain and teach works for me! Thanks so much! 73
I have been a Patreon for over 2+ years, He is in a rut, old radios most of the time. So, ,, mostly but you're into old repair he is the best. I like test equipment, He got over 2 million $ in test equipment. So a lot to choose from. The best for troubleshooting .
Hello, great video! I finally figured out how you find all your minty fresh vintage gear; you arrived here on a spacecraft powered by a VTWD - Vacuum Tube Warp Drive - so obviously you have a time machine to go back and find the best vintage kit. I also now know who REALLY invented the internet. But not to worry, your secret is safe with me. ;)
Great timing on this video and great job. I was already planning on refreshing my Heathkit 2717 this week. Now I know much more than I did an hour ago! As you most likely already know, the 2717 is almost identical to the IP-32 but has a 12.6VAC output on front and a little more modern package. I followed along with my schematic and it now makes much more sense. Keep up the great work. Doc
Great video Paul!! Really enjoyed the deep dive detail of your circuit descriptions. Your suppositions about Heathkit and the tubes they used sounds about right. Also your perceptions about the excellent engineering Heath used matches what I've read from former Heath engineers. Every time I see your intro, with all those heavy scopes around you, as a Seattle area resident, all I can think is "I hope you're not in earthquake country!" 😂
Very well done, Paul, thanks for another great restoration video! So, you got bit by a charged cap you thought was safe, eh? I don't feel like such a schlemiel now. In my young and foolish days I once got thrown across my dorm room by an unknown power transformer that I was testing without protection. Landed on my couch ten feet away -- lesson learned, let me tell you! Thanks for reiterating your now famous safety message in every one of your videos. They are well needed and appreciated!
Wow, what a great video including a long "how it works" part according to the schematic, which is always my favorite part in your videos. Can't tell enough, what a great teacher you are! After you releases two great video with only a couple of days in between, I assume you have to catch up on some sleep :) Thanks for all you do Paul!
I always enjoy the way you teach...and all the nifty little tid-bits of information that most folks would never hear. My grandfather used to do that when i was growing up...he got me into math & electronics very early. Used to LOVE going into Radio Shack to use the vacuum tube tester they kept by the door :)
Another excellent video. Not just a good presentation, but good education. He is so very good about explaining the theory of operation as well as the little "gotchas" to look out for with all the experience he has. Thanks so much for posting the great videos and look forward to more soon!
Hi Paul! Great job as usual explaining the tube regulator circuit, you made it very easy to understand, thank you. I have tried a few times to win one of these old Heathkit power supplies on eBay and always get outbid. I can build one like this in solid state for around $200 and have most of the components except for the filter caps. I am very comfortable working around high voltage and current as I have worked on industrial three phase 480VAC equipment for years. That said I have been planning to scratch build a 0-600VDC, 450mA power supply of my own design for doing vacuum tube experiments. I have a toroidal transformer, center tapped for 430/430 VAC secondary and two 6.3VAC, 4A taps so I will have a negative supply for bias and upto 600+ volts for the B+ as well as ample power for heaters. I am going to use an FET for the pass element and op amp and zener diode for feedback voltage control and monitor the output with analog voltage and current meters. I should look pretty cool as I am repurposing an HP case.
Nice as always, Paul! I have the same power supply and have used it much for powering tube circuits. I have removed the 6X4 tube and put in two silicon diodes. The free 6.3V winding I have brought out on the front, giving me an extra filament supply
I particularly liked this episode for those wonderfully explained, concise, intimate knowledge tidbits that tend to never make it into the texts. Watching your vids, I feel like I'm becoming better armed when I tackle something. ~32:58 .. Who knew. I suppose (as you stated) with modern Si rectifiers the point is moot, but wouldn't small value snubber caps prevent this? Their absence presumably due to manufacturing to cost? For those who use their old tube gear as opposed to restore to shelf condition, curious as to what other measures might be taken - added - to improve on original design, the cost of modifying "one offs" for personal use rarely an issue.
Thanks for the discussion about filament to cathode breakdown. When I was studying this schematic I was really scratching my head about why they would have connected the AC to the cathodes, and why I didn't see any hum on the output as a result!
I love it, Ohmite, Skokie, made in USA. Ohmite closed the Skokie (a Chicago suburb) factory in 1998, moved factory to Mexico, moved offices a few times over the years but still in the area.
Thank you Mr Carlson I watch this video and follow exactly your instruction to repair a unit exactly like yours. The power supply now is working and calibrated to within a volt. Thanks again!
Enjoyed this video. I have one of these power supplies that I restored. Mine was pretty beat up when I got it: bent panel and cabinet, stripped out setscrews on the knobs, water damage, and broken off binding posts. But, she works well, now. I also have a Heathkit PS-3 that I restored. This unit outputs up to 500 vdc.
I love the large VR...I haven't seen one that large since I worked on very high power transmitters many years ago. 20 kilowatt transmitters in the service. Thanks again
@@NanookFieryArcticSkyy Yes 20 KW Radio transmitters. I worked on the FRT-49 High Power Transmitters. used with the GKA--5 data control systems when I was in the Air Force many years ago.
I have two of these power supplies. One I bought working and one I had to repair. I have an original manual with schematic and construction instructions. They originally had Selenium rectifiers instead of the diodes. One of my units still has the Selenium rectifier the other replacement diodes. Good find.
YAY! New video! Thank you very much Paul! Your content is top notch! Always wondering about HV power supplies. Jeez, I guess Heathkit made every possible piece of test gear! xD Cheers, Phil.
It's really amazing, the amount of "devices" of all sorts that Heathkit made over the years. From simple battery testers and crystal radio kits, to complex test gear, 2 way radio equipment, Audio equipment, color TVs and even computers in their later days. There were other kit manufacturers such as Eico, Knight Kit and others that made learning electronics fun, while equipping your shop with well designed service grade equipment. I think Heathkit was the most prolific, though. It's a much loved and much missed brand. I think it's really cool that, in recent years, you can buy a kit to build just about anything (from China). Their recent popularity is keeping the memory of Heatkit and the others alive. The quality isn't the same, but it is feeding that spark of curiosity in younger people, much like Heathkit did years ago.
Hi Paul, have you ever thought of placing a small, long lasting, label inside or outside of the devices you repair? "Restored to life. Mr Carlson, 2018" That sort of thing. It adds provenance and value. Graham (Australia)
Your comment about the use of regulator tubes in old ham transmitters. The old Heathkit DX 40 transmitters were known for a chirp when keyed. If I remember correctly the regulator tubes were 0A2 I don't recall there being a control or pass tube, which might have explained the less than great regulation. Great video. I may pick up one of those old Heathkit power supplies for my bench.
Enjoyed all the theory in this supply. I really appreciate your explanations of operation. A bit of reality and insight into design decisions. Really great. Thanks so much.
Ground lead to the chassis, bummer! I made a simular mistake in a Heathkit IG-102. Added a three prong cord in the name of safety and later realized I was shorting half the filiment suppy to ground. Ditched the three prong for a polarized cord and all was well. Good stuff Paul nice video.
Paul I would love to see 'before and after' pictures either side by side or one after the other when you have done a restoration to see (quickly) just how much nicer you have made your projects.
Great video as always, by Paul Carlson, The GREAT ELECTRONICS TEACHER, possibly of all time !!!! By the way I just bought an old Heathkit regulated power supply model PS - 3 to work on and clean up. my unit only has one physical meter in upper center front, meter has two functions, switch selectable either voltage or current, looks like it might supply 450 to 500 volt max at maybe 150 ma. I will have to open it up and see what differences in circuit design there is between yours and mine. Once again thanks Paul, 73's de KC2UVN John Bellas
Awesome video, thanks for walking us through the circuit. Great job with going over and re-doing the wiring. I could view for another hour, to watch you doing that.
I enjoyed the video. I didn't understand your discussion of the 3 wire versus 2 wire power cord for this device. You spoke of a scenario of using this power supply and a guitar amp. at the same time. I didn't catch the point however. I would say that Heathkits like this present a challenge to folks who want to use a 3 wire power cord and that is that the front and back chassis cases have no electrical connection. So adding an earth lug to the front chassis leaves the back chassis unconnected. The press fit on the front of the unit between the two chassis may provide ground or it may not.
Great video Paul, thanks. It turns out that I had picked up one of these units about a month before your video came out, thus avoiding the dreaded Dave Jones effect :-)
I went to a technical high school and took electronics for 4 years and we all had to buy and build a VTVM and that very Heathkit power supply in 1962. Sixty years later it's still on my bench and I still have the original anual, let me know if you need a copy.
Nice. I have an older version of this supply (PS-4; exact same circuit, different part number, just older styling on case). It works well. Daystrom would be the original branding on the tubes. Watch out for R7 -- there's almost 700V across that resistor! (The original 1Meg carbon comp resistor had badly drifted in mine, and I replaced it with 3x 330K resistors in series ... commonly available metal film resistors are rated for only 350V!)
I was following along with the schematic of my Heathkit IP-17 which was the later model of that supply and found a couple of interesting differences. First, the supply has a three-line cord, the OA2's don't reflect any internal connections for the "discharge safety" you talked about, and finally the 6L6 heater to cathode connections aren't reflected at the tube socket but at the transformer windings so the effect isn't as clear as you described. Probably a couple of other minor differences. Thanks for the run through Paul, another great video! 73 - Dino KL0S
these are always fun to watch. i learn fair bit watching these. i really want to restore my vintage tube radios but im just scared of ruining the value by changing parts out so i leave them as show pieces only.
Wow, the best! Thank you Mr Carlson! Was wondering about how operates and how would, if able, to make into like a Prius NiMH battery charger like what they call the grid chargers to charge the whole packs at HV instead of reconditioning the individual modules. Seems like close enough spec, though 300 to 700mA and maybe more might be useful. I got one of these for free and never touched since is like one of three tube electronics lab test equipment I own. The others being the H12-175A HP oscilloscope, Heathkit GD-1B and I guess now that I think about the Admiral TV (which I only wanted for components) and is really only left as parts since I remove them all and kept the case as a lab bench stand. Figure I really need to sit down and read so I understand the do's and do not's with confidence and very safely while still doing. Anyways, neat learning about the HV power supplies from the range of tube designs up to the HF transistor based designs. Seems kind of neat retro if can use the IP-32 to charge the Prius battery, even as a tender for when sits extended times to keep those old batteries new enough. This video really advanced my understanding of the tube designs. Wow, the best!
Great video, Paul. It is interesting to see how "regulation" was accomplished in the vacuum state era. Depending on one's perspective, it could be easier to "see" versus the solid state technology; which is usually accomplished with an IC and discrete transistors. Excellent work!
May I suggest a Part 2 on how the 6BH6 circuit acts as the output voltage is varied with a fixed load. Thanks for presenting a piece of gear that many of us treat as a 'black box'.
Great video! I picked up a couple of Philbrick op amps after your last video, and was thinking about a power source. I got lucky and found a Philbrick R-100B +/-300V, 100mA supply. The tubes were missing, but I replaced them, and fired it up with a dim bulb tester in the input, and it works fine. The line reg is perfect
Mr Carlson's Lab Sorry it took so long to reply. I was planning on doing a video, but I didn’t want to commit until I was sure I could accomplish the task. I’m putting the finishing touches on a “show-and-tell” video for the R-100B. I got a little carried away, so it’s a little over 40 minutes long, but I cover the manual and circuits briefly, and talk about some of the Philbrick literature I have. I hope to upload it tonight or tomorrow. Thanks for the suggestion.
@@GeorgeZ213 I was talking about snubber network back then (and when I commented on this video, I actually didn't know the term but knew what it did, it's hilarious).
Really enjoying the Video's Mr Carlson, your skill and knowledge is inspiring. Would really like to see a faulty CD player repair, especially the older pesky Cyrus player's plagued with read disk errors.
Oh yeah, I remember when I was a kid watching my dad working on a CRT TV around 1975. He made a mistake and the electricity lifted him off of the stool and threw him back in the air into the wall! He took a break for awhile after that.
Amazing how crt tubes can pack such a wallop. Especially if the flyback and rubber coated side connector was still intact. 21in crt had around 20kv I believe.
Have you seen any of Glasslinger's videos? She makes her own vacuum tubes! Tin hat tubes. Xray tubes. Nixie tubes!. does all the glass work and everything herself!
WTF HEISENBERGDL? are you a troll? you are implying that blowing your own glass and making your own nixie tubes,diodes, triodes etc, making the heaters, anode cathode control grids, all the chemicals and machinery needed , creating and sealing the vacuum, using "exotic" metals , depositing the getter and flashing it, spot welding all together by hand, knowing the clearances and size of parts etc etc etc that is EASY? or that it is less involved than repairing stuff??? as much as i like mr carlsons videos FORGET its not even the same league... you are implying that designing and fabricating your own vacuum tubes at your home or shop is less involved than replacing those tubes and replacing capacitors to make stuff work? are you really saying that? are you a flat earther also????? gotta be kiddin....
Another enjoyable video mr Paul! A lots of information that I got and also great explanation. Thank you so much for this episode... I may suggest that you may do some video of back-up power supply restoration in a desktop computer if ever you may like? Have a nice day.
Mod suggestion: What do you think about adding a low value power series resistor in both 6L6 plates? That would help current sharing between the two pass tubes. When this was sold new, matched tubes were a lot easier to get. Not anymore. I have the next generation of this unit, the IP17 which is almost identical schematic wise. Good unit!
I once got a Radio Shack "Psychostrobe" working which looked like it sat in water for a while. I replaced all but one capacitor, one of the rectifiers and two resistors. I was lucky to be able to find the two 20mfd tank capacitors locally. And you can still buy the strobe lamp it uses.
I may be misrememberizing things, but I seem to recall testing an 0A2 tube on my Dad's old Heathkit checker back in the '70s and the whole tube glowed. It's a cold cathode tube, isn't it?
Hello Mr. Carlson, I was wondering about building a 1 tube guitar amp using a 6GF7A. Naturally, I'm thinking of using one half of the tube as preamp and the other output. Is this tube suitable? Thank you , William
Hi William. The 6GF7 is a dissimilar dual triode that wouldn't make very much power in audio service. If you wanted to use a compactron type tube, the 6LU8 would be a better choice, and provide some output power.
You are incredible just a gifted person, I wish on my best day I could be as good as you on your worst....lol I am still having trouble with troubleshooting both tube and solid-state electronics. I read a schematic and there are both resistance and voltage values at tube pins, I check the resistance value it's fine but I can't trace the low or too high voltage readings. I use both a DMM and a VTVM so as not to load down the circuit. Example would be at the #2 pin of a 6AU6, 47K / -9.0 vdc Could you do a video on correctly troubleshooting electronic circuits? Thanks, Tony
Nice overhaul, im sure it'll be a useful addition...Bit of an afterthought as you have already finished it now but assuming it was operating before you restored it it would have been nice to see a scope trace of the DC rail before and after you sorted the wiring out to get a visual idea of noise reduction through component / wiring placement.. An old timer I know just recently finished an 11 tube "all GT" MW/SW PP. The amount of experimentation he did with component and wiring placement was verging on OCD but it is one of the quietest sets i've ever heard, even at near full volume there is little to no percievable noise.
OK. I'm in the process of restoring mine and it still has the two selenium rectifiers. Yours had them removed by the previous owner and a dropping resistor added. I got that much. (The schematic indicates 270 volts is correct) Your pre-restoration has the dropping resistor and the 1000 ohm resistor I see in the schematic. Your post-restoration only has one (3 watt?) resistor there, no 1K resistor? What am I missing? By the way, mine was factory wired and is really well done! Neat. Orderly. Thanks again!
Have you checked if the negative supply output varies depending on the position of the meter switch? The schematic makes it look like there would be a significant change doing that. Adding a zener diode can fix that.
Thanks for this video! Any suggestions for the cause of the following issue? When I switch the supply turning on the high voltage ,I get a big momentary pulse of power that has actually taken out solid state devices in the hv path. Otherwise the supply works fine. thanks
Looking at the schematic, I see that it might have been a good idea to put a high resistance in parallel with each of the diodes that are in series. Something around 1M as shown on schematics for transmitting supplies in the ARRL handbook. I was thinking about what you said about the spike when turning the supply off is something that many of us never think about. I have seen what you said about capacitors blowing up when put into circuit backwards, They get hot really fast then blow out all of their liquid.
May I ask why you suggest running twisted AC lines to the chassis when working with point to point when I've noticed ever audio amp and guitar amp has them as far away from the chassis as possible. Even uncle Doug suggests to do so.
Hi Stefano. There is a lot of misleading information out there due to the lack of understanding AC, and AC filament systems. The chassis is common to the high sensitive circuitry, and acts as shielding. "High floating filament lines" are only common practice with remote tube sockets extended with wires from a circuit board or eyelet board. This type of build is common in guitar amps, "NOT" in High Fidelity applications. You will notice when you turn the gain (volume) up on a guitar amplifier with this type of circuitry (HFFL), they are far from quiet. Here is some good information right from RCA. Go to page 92 of the PDF (actual book page 90) and start reading "High Fidelity Systems." This is continued to the next page, you will find many of your answers there. Here is a link to the RCA manual: www.nj7p.org/Manuals/PDFs/Tubes/RCA-RC-27-1970.pdf
@@MrCarlsonsLab thank you kindly. I think I understand. However, when I watch guys like Terry from D-Labs and Uncle Doug, they suggest the HFFL method to avoid noise. Often boasting about the amp being quiet and adding that one of the attributes to this is the HFFL. I haven't read the link the to RCA book yet. But I will do so to get a better understanding, as my lack of understanding as of now is making me believe there's a place for each type of filament wiring method based on the circuit design, nature and intended use. So, is this why when I repair a more modern guitar amp with a circuit board, the filament connection is either on the board in straight lines, somehow avoiding any noise injection. Or like in some Orange guitar amps, the filaments are untwisted wire that's not exactly hovering high above the circuit board. I first thought it was maybe a DC voltage. But upon measuring, I was wrong. More research is required. Thank you for your time and details response.
![HeathBuilt Voltage Reference Source [Restoration]](http://i.ytimg.com/vi/2LlOGOu8Dlg/mqdefault.jpg)
If you're interested in learning how to troubleshoot electronics like a pro, check out Mr Carlson's Patreon page, click here: www.patreon.com/MrCarlsonsLab
looking at you on power supply on v4 6x4 why is there 300v on v4 on 2 anode
I have a question since I know very little about tube circuits. I bought this device off an estate sale, it has two OD3A tubes, a very large Mallory cap and a giant transformer with lots of secondary outputs. The front of the chassis has one pot and the rear has an eight pin tube socket. Is this thing a power supply ? I looked inside and it not only looks homemade, but it's pretty clean. I just dont know tubes enough to make an educated guess. Oh, I probed the eight pin socket and I found- adjustable 250 vdc to just over 450 vdc, a steady 350 vdc, and the common filament voltages. Any idea ? Thank you.
I haven recently become a Patreon to further your cause which is informing (and trough that, entertaining :-) ) all of us tech-curious people who are connected and brought together by your excellent video's, projects and knowlage in general.
Everytime a new video appears on your channel I am sure it's going to be well worth watching. And I am sure that I will learn something new everytime. Awesome :D
Thanks a million times and keep on teaching, Mr Carlson !
"Diodes have Jumper-envy"
You see? :D
Yea, yet another thing learned today !
Greetings Raoul,
The Netherlands
I learned a lot on this restoration. Yours, and mine. I did not need dropping resistors after replacing the selenium rectifiers. The voltage was actually a hair below 270 volts. Also, I could not zero the voltage. The 680K resistor after the CWA pot measured 780k! I tested the circuit and determined a lower resistor was needed to allow me to zero the output. 680k was still too high. A 560K resistor put the CWA pot right in the middle of travel when the voltage was zeroed. Perfect. I’m very pleased with the supply and the great learning experiences. Thanks for the help.
Rarely I can finish a movie or show or any type of related programs, regardless of having many sources to entertain my self, your videos are really easy to watch, learn new things and enjoy every moment of.
Man does that bring back memories. Graduated from tech school in 1963 many of my friends went to work for heathkit in Benton harbor Michigan. 7 years after I graduated my education was outdated because of semiconductors. Thanks mr Carlson for the presentation did a fabulous job on chalk talk through the schematic need a lot of this when servicing circuit board schematics keep up the good work this is Wb8idy in Swansboro nc very very well done from brian
Heathkit was great company. The staff really did care about their products and the assembly manuals were very well written.
Well if you are into electronics it doesn't get much better than this channel,truly excellent!!
Agreed.
Mr. C, thanks for explaining the dual feedback voltages on V3, the 6BH6 control tube. You did a great job.
Another excellent teaching video! I am proud to support you on Patreon! If I have any complaint at all, I can watch the video in the run time, in this case, 58.42 minutes with the result of WANTING MORE LOL! I have made a few videos and know just HOW MUCH time it takes to film, edit and produce a video so I understand the time factor! Again, thank you for the huge effort it takes to produce these for us!
I am a huge fan of the two tone gray heathkit equipment. And I really enjoy Mr. Carlson's videos! I have a great deal of appreciation for experts who are willing to help the beginners. That says a lot about someone's knowledge, but much more about their character!
I wish the Heathkit company was still around. I would love to build these projects daily. Thanks for the video.
Heath kit was still popular in the tech community when I was growing up in the 70s. I sure miss them. Reading their catalogs was so fun to a wannabe young techie. My maternal grandpa got me hooked real good.
They still sell a couple of items, nothing really interesting. I was looking at a catalogue from the late 1950's. The average American must have been earning damn good money back then, because most of the prices were way beyond what average folks elsewhere could afford.
@@Frankowillo So true. Many Heathkits are still beyond the reach of the average person because I continually see eBay scalpers advertising so-called "restorations" of old kits and on-selling them at ludicrous prices beyond what reality should dictate. If vintage fanboy Hipsters keep paying these high prices and keep turning good test gear into bedside lamps, they'll keep driving up demand, therefore price. Heathkit gear is nostalgic, but in many cases is still necessary especially for testing tube gear (such as tube oscilloscopes that can handle high voltage when fixing radios and Amps) unlike many modern digital test devices that will get blown out if any HV touches them (requiring work-arounds).
I, as a young lad once surprised myself with a cheap broken camera. The flash unit cap was charged and upon touching it, I threw it to the opposing wall and jumped back a good length too. When I went to inspect, it still held about 300V. Didn't expect that from a device that took 3 AA batteries, but I got wiser quick.
Paul, I had a rough day. Watching this video makes me feel relax again. Good explanations, great content.
A new ham of 3 yrs. Many years in minor to some moderate electronic repairs of sorts and always trying to learn. Great explanations. I am just learning vacuum tube technology and having a blast. I am so glad I have come across your channel. The way you explain and teach works for me! Thanks so much! 73
I am 62; ,this is the first time I've seen the innards (or even studied) a tube-based (regulated, variable) power supply!
Great video, Paul.
Nice visual representation of how linear voltage regulators work!
Thanks!
I have been a Patreon for over 2+ years, He is in a rut, old radios most of the time. So,
,, mostly but you're into old repair he is the best. I like test equipment, He got over 2 million $ in test equipment. So a lot to choose from. The best for troubleshooting .
Very impressive power supply. Simple resto and lots of info about the circuitry within. I learned a lot about this type of design, thanks Paul.
You're welcome Jim!
You make a great teacher Paul, clear, calm, and very thorough. I enjoy these videos of yours very much.
Hello, great video! I finally figured out how you find all your minty fresh vintage gear; you arrived here on a spacecraft powered by a VTWD - Vacuum Tube Warp Drive - so obviously you have a time machine to go back and find the best vintage kit. I also now know who REALLY invented the internet. But not to worry, your secret is safe with me. ;)
probably on of the best youtube comments ever thanks paul for your amazing video and that fwr for your amazing comment
"Chung", Soooo....those are out of there....Love it! Cheers to a great teacher :)
Thanks Jason!
Great timing on this video and great job. I was already planning on refreshing my Heathkit 2717 this week. Now I know much more than I did an hour ago! As you most likely already know, the 2717 is almost identical to the IP-32 but has a 12.6VAC output on front and a little more modern package. I followed along with my schematic and it now makes much more sense. Keep up the great work. Doc
Great video Paul!! Really enjoyed the deep dive detail of your circuit descriptions. Your suppositions about Heathkit and the tubes they used sounds about right. Also your perceptions about the excellent engineering Heath used matches what I've read from former Heath engineers. Every time I see your intro, with all those heavy scopes around you, as a Seattle area resident, all I can think is "I hope you're not in earthquake country!" 😂
Jumper envy. That's the good life! BAHAHAHA! 🤣
Very well done, Paul, thanks for another great restoration video! So, you got bit by a charged cap you thought was safe, eh? I don't feel like such a schlemiel now. In my young and foolish days I once got thrown across my dorm room by an unknown power transformer that I was testing without protection. Landed on my couch ten feet away -- lesson learned, let me tell you! Thanks for reiterating your now famous safety message in every one of your videos. They are well needed and appreciated!
Wow, what a great video including a long "how it works" part according to the schematic, which is always my favorite part in your videos. Can't tell enough, what a great teacher you are! After you releases two great video with only a couple of days in between, I assume you have to catch up on some sleep :) Thanks for all you do Paul!
Thank You Ralf! I could definitely use some more sleep. Now on to the next video.....
Reb Elba he's like the Bob Ross of electronics😄
I always enjoy the way you teach...and all the nifty little tid-bits of information that most folks would never hear.
My grandfather used to do that when i was growing up...he got me into math & electronics very early.
Used to LOVE going into Radio Shack to use the vacuum tube tester they kept by the door :)
Another excellent video. Not just a good presentation, but good education. He is so very good about explaining the theory of operation as well as the little "gotchas" to look out for with all the experience he has. Thanks so much for posting the great videos and look forward to more soon!
Hi Paul!
Great job as usual explaining the tube regulator circuit, you made it very easy to understand, thank you. I have tried a few times to win one of these old Heathkit power supplies on eBay and always get outbid. I can build one like this in solid state for around $200 and have most of the components except for the filter caps. I am very comfortable working around high voltage and current as I have worked on industrial three phase 480VAC equipment for years. That said I have been planning to scratch build a 0-600VDC, 450mA power supply of my own design for doing vacuum tube experiments. I have a toroidal transformer, center tapped for 430/430 VAC secondary and two 6.3VAC, 4A taps so I will have a negative supply for bias and upto 600+ volts for the B+ as well as ample power for heaters. I am going to use an FET for the pass element and op amp and zener diode for feedback voltage control and monitor the output with analog voltage and current meters. I should look pretty cool as I am repurposing an HP case.
I built one of those back in 1962 for my electronics course in HS along with a heath VTVM, I still have both and they still work fine.
Nice as always, Paul! I have the same power supply and have used it much for powering tube circuits. I have removed the 6X4 tube and put in two silicon diodes. The free 6.3V winding I have brought out on the front, giving me an extra filament supply
I particularly liked this episode for those wonderfully explained, concise, intimate knowledge tidbits that tend to never make it into the texts. Watching your vids, I feel like I'm becoming better armed when I tackle something.
~32:58 .. Who knew. I suppose (as you stated) with modern Si rectifiers the point is moot, but wouldn't small value snubber caps prevent this? Their absence presumably due to manufacturing to cost? For those who use their old tube gear as opposed to restore to shelf condition, curious as to what other measures might be taken - added - to improve on original design, the cost of modifying "one offs" for personal use rarely an issue.
Thanks for the discussion about filament to cathode breakdown. When I was studying this schematic I was really scratching my head about why they would have connected the AC to the cathodes, and why I didn't see any hum on the output as a result!
Excellent restoration Paul. I really enjoyed the theory on the inner workings of this piece. Thanks for another great video.
Another Hour well spent ! Big fan on both youtube and patreon . Thanks again for all the work you put into these video's Paul !
I love it, Ohmite, Skokie, made in USA. Ohmite closed the Skokie (a Chicago suburb) factory in 1998, moved factory to Mexico, moved offices a few times over the years but still in the area.
Thank you. Reminds me of the repairs I did on laboratory equipment.
You're welcome Glen.
Thank you Mr Carlson I watch this video and follow exactly your instruction to repair a unit exactly like yours. The power supply now is working and calibrated to within a volt. Thanks again!
Your videos are so in-depth and well made. Extremely niche and intriguing, I could watch this all day
Enjoyed this video. I have one of these power supplies that I restored. Mine was pretty beat up when I got it: bent panel and cabinet, stripped out setscrews on the knobs, water damage, and broken off binding posts. But, she works well, now. I also have a Heathkit PS-3 that I restored. This unit outputs up to 500 vdc.
I love the large VR...I haven't seen one that large since I worked on very high power transmitters many years ago. 20 kilowatt transmitters in the service. Thanks again
When you say 20kw are you talking about radio tranmitters? My father was a radio engineer for commercial radio in FL.
@@NanookFieryArcticSkyy Yes 20 KW Radio transmitters. I worked on the FRT-49 High Power Transmitters. used with the GKA--5 data control systems when I was in the Air Force many years ago.
I have two of these power supplies. One I bought working and one I had to repair. I have an original manual with schematic and construction instructions. They originally had Selenium rectifiers instead of the diodes. One of my units still has the Selenium rectifier the other replacement diodes. Good find.
Very nice explanation.
YAY! New video! Thank you very much Paul! Your content is top notch!
Always wondering about HV power supplies.
Jeez, I guess Heathkit made every possible piece of test gear! xD
Cheers, Phil.
It's really amazing, the amount of "devices" of all sorts that Heathkit made over the years. From simple battery testers and crystal radio kits, to complex test gear, 2 way radio equipment, Audio equipment, color TVs and even computers in their later days.
There were other kit manufacturers such as Eico, Knight Kit and others that made learning electronics fun, while equipping your shop with well designed service grade equipment. I think Heathkit was the most prolific, though. It's a much loved and much missed brand.
I think it's really cool that, in recent years, you can buy a kit to build just about anything (from China). Their recent popularity is keeping the memory of Heatkit and the others alive. The quality isn't the same, but it is feeding that spark of curiosity in younger people, much like Heathkit did years ago.
Hi Paul, have you ever thought of placing a small, long lasting, label inside or outside of the devices you repair? "Restored to life. Mr Carlson, 2018" That sort of thing. It adds provenance and value. Graham (Australia)
Graham Okely , OMG... you read my mind! LOL
very enjoyable and i agree with Reb get some rest MR. Carlson cause we wan't more please
Mr Carlson, you have really nice hands.
Fantastic video and explanation of this type of supply - I learnt a great deal!
Your comment about the use of regulator tubes in old ham transmitters. The old Heathkit DX 40 transmitters were known for a chirp when keyed. If I remember correctly the regulator tubes were 0A2 I don't recall there being a control or pass tube, which might have explained the less than great regulation. Great video. I may pick up one of those old Heathkit power supplies for my bench.
Enjoyed all the theory in this supply. I really appreciate your explanations of operation. A bit of reality and insight into design decisions. Really great. Thanks so much.
Ground lead to the chassis, bummer! I made a simular mistake in a Heathkit IG-102. Added a three prong cord in the name of safety and later realized I was shorting half the filiment suppy to ground. Ditched the three prong for a polarized cord and all was well. Good stuff Paul nice video.
Thanks Steve!
Paul I would love to see 'before and after' pictures either side by side or one after the other when you have done a restoration to see (quickly) just how much nicer you have made your projects.
Great video as always, by Paul Carlson, The GREAT ELECTRONICS TEACHER, possibly of all time !!!! By the way I just bought an old Heathkit regulated power supply model PS - 3 to work on and clean up. my unit only has one physical meter in upper center front, meter has two functions, switch selectable either voltage or current, looks like it might supply 450 to 500 volt max at maybe 150 ma. I will have to open it up and see what differences in circuit design there is between yours and mine. Once again thanks Paul, 73's de KC2UVN John Bellas
Thank You for your kind comment John!
Awesome job mr Carlson big thumbs up 👍
You've a rare talent and thank you for sharing it'
Thanks for your kind comment Orange!
Awesome video, thanks for walking us through the circuit. Great job with going over and re-doing the wiring. I could view for another hour, to watch you doing that.
I enjoyed the video. I didn't understand your discussion of the 3 wire versus 2 wire power cord for this device. You spoke of a scenario of using this power supply and a guitar amp. at the same time. I didn't catch the point however. I would say that Heathkits like this present a challenge to folks who want to use a 3 wire power cord and that is that the front and back chassis cases have no electrical connection. So adding an earth lug to the front chassis leaves the back chassis unconnected. The press fit on the front of the unit between the two chassis may provide ground or it may not.
Great video Paul, thanks. It turns out that I had picked up one of these units about a month before your video came out, thus avoiding the dreaded Dave Jones effect :-)
I went to a technical high school and took electronics for 4 years and we all had to buy and build a VTVM and that very Heathkit power supply in 1962. Sixty years later it's still on my bench and I still have the original anual, let me know if you need a copy.
Nice. I have an older version of this supply (PS-4; exact same circuit, different part number, just older styling on case). It works well. Daystrom would be the original branding on the tubes. Watch out for R7 -- there's almost 700V across that resistor! (The original 1Meg carbon comp resistor had badly drifted in mine, and I replaced it with 3x 330K resistors in series ... commonly available metal film resistors are rated for only 350V!)
Very nice. The detailed explanations are very much appreciated.
Another excellent video!
I was following along with the schematic of my Heathkit IP-17 which was the later model of that supply and found a couple of interesting differences. First, the supply has a three-line cord, the OA2's don't reflect any internal connections for the "discharge safety" you talked about, and finally the 6L6 heater to cathode connections aren't reflected at the tube socket but at the transformer windings so the effect isn't as clear as you described. Probably a couple of other minor differences. Thanks for the run through Paul, another great video! 73 - Dino KL0S
MY 2717 schematic has a note by the third prong that states "if used". Which cord is actually on your unit?
I didn't build this unit; it has the three-wire cord on it.
Mr Carlson - Neil Peart - Geddy Lee & Alex Lifeson - How can this get better : )
Super développement explicatif, les tubes électronique sont plus fiables pour les alimentations HT,MERCI !!!
De rien.... I hope thats right.
these are always fun to watch. i learn fair bit watching these. i really want to restore my vintage tube radios but im just scared of ruining the value by changing parts out so i leave them as show pieces only.
Just because the circuit doesn't look complex don't assume a lot of thought didn't go into the design. The genius is in the elegance.
Wow, the best! Thank you Mr Carlson! Was wondering about how operates and how would, if able, to make into like a Prius NiMH battery charger like what they call the grid chargers to charge the whole packs at HV instead of reconditioning the individual modules. Seems like close enough spec, though 300 to 700mA and maybe more might be useful. I got one of these for free and never touched since is like one of three tube electronics lab test equipment I own. The others being the H12-175A HP oscilloscope, Heathkit GD-1B and I guess now that I think about the Admiral TV (which I only wanted for components) and is really only left as parts since I remove them all and kept the case as a lab bench stand. Figure I really need to sit down and read so I understand the do's and do not's with confidence and very safely while still doing. Anyways, neat learning about the HV power supplies from the range of tube designs up to the HF transistor based designs. Seems kind of neat retro if can use the IP-32 to charge the Prius battery, even as a tender for when sits extended times to keep those old batteries new enough. This video really advanced my understanding of the tube designs. Wow, the best!
Great video, Paul. It is interesting to see how "regulation" was accomplished in the vacuum state era. Depending on one's perspective, it could be easier to "see" versus the solid state technology; which is usually accomplished with an IC and discrete transistors. Excellent work!
This is a beautiful looking (and functioning) unit. It may be trite but they truly don't make 'em like they used to.
you should be the dean of MIT
May I suggest a Part 2 on how the 6BH6 circuit acts as the output voltage is varied with a fixed load.
Thanks for presenting a piece of gear that many of us treat as a 'black box'.
Great video! I picked up a couple of Philbrick op amps after your last video, and was thinking about a power source. I got lucky and found a Philbrick R-100B +/-300V, 100mA supply. The tubes were missing, but I replaced them, and fired it up with a dim bulb tester in the input, and it works fine. The line reg is perfect
If you get a chance, post a small video displaying your work and the power supply. Thanks for sharing Tim!
Mr Carlson's Lab Sorry it took so long to reply. I was planning on doing a video, but I didn’t want to commit until I was sure I could accomplish the task. I’m putting the finishing touches on a “show-and-tell” video for the R-100B. I got a little carried away, so it’s a little over 40 minutes long, but I cover the manual and circuits briefly, and talk about some of the Philbrick literature I have. I hope to upload it tonight or tomorrow. Thanks for the suggestion.
Can we connect very low value capacitors across the diodes to prevent the diodes turning into jumpers?
If the diode blows, I would replace it with the next higher voltage rating.
@@GeorgeZ213 I was talking about snubber network back then (and when I commented on this video, I actually didn't know the term but knew what it did, it's hilarious).
Another great video,Enjoyed every minute of it,Thank you.
Really enjoying the Video's Mr Carlson, your skill and knowledge is inspiring. Would really like to see a faulty CD player repair, especially the older pesky Cyrus player's plagued with read disk errors.
Oh yeah, I remember when I was a kid watching my dad working on a CRT TV around 1975. He made a mistake and the electricity lifted him off of the stool and threw him back in the air into the wall! He took a break for awhile after that.
Amazing how crt tubes can pack such a wallop. Especially if the flyback and rubber coated side connector was still intact. 21in crt had around 20kv I believe.
Have you seen any of Glasslinger's videos? She makes her own vacuum tubes! Tin hat tubes. Xray tubes. Nixie tubes!. does all the glass work and everything herself!
Thanks for the tip o/
Nixie tubes? Do u have any idea how much more involved what mr carlson does is then nixie tubes and glass blowing the two are not even related.
WTF HEISENBERGDL? are you a troll? you are implying that blowing your own glass and making your own nixie tubes,diodes, triodes etc, making the heaters, anode cathode control grids, all the chemicals and machinery needed , creating and sealing the vacuum, using "exotic" metals , depositing the getter and flashing it, spot welding all together by hand, knowing the clearances and size of parts etc etc etc that is EASY? or that it is less involved than repairing stuff??? as much as i like mr carlsons videos FORGET its not even the same league... you are implying that designing and fabricating your own vacuum tubes at your home or shop is less involved than replacing those tubes and replacing capacitors to make stuff work? are you really saying that? are you a flat earther also????? gotta be kiddin....
its a guy dressed in drag
Glad someone is still making them. They (tubes/valves) are fast becoming super hard to find.
iI enjoy the power supply repair. I would like to see more desizn and repair videos. your videos are very informative.
alan kellerhouse
Another enjoyable video mr Paul! A lots of information that I got and also great explanation. Thank you so much for this episode... I may suggest that you may do some video of back-up power supply restoration in a desktop computer if ever you may like? Have a nice day.
Mod suggestion: What do you think about adding a low value power series resistor in both 6L6 plates? That would help current sharing between the two pass tubes. When this was sold new, matched tubes were a lot easier to get. Not anymore. I have the next generation of this unit, the IP17 which is almost identical schematic wise. Good unit!
25:40 - My guess is that they used a vacuum tube on the regulated supply to provide a 'soft-start' on power-up.
From a glance, that would actually work .. it keeps the 6BH6 fully open and therefore the output low until the bias rectifier comes alive?
I once got a Radio Shack "Psychostrobe" working which looked like it sat in water for a while. I replaced all but one capacitor, one of the rectifiers and two resistors. I was lucky to be able to find the two 20mfd tank capacitors locally. And you can still buy the strobe lamp it uses.
Slightly OT, but 6BH6 tubes were also used by the dozen in old GE Progress Line communcations equipment - both the receiver and transmitter strips!
Great video as always Paul keep up the great work
I may be misrememberizing things, but I seem to recall testing an 0A2 tube on my Dad's old Heathkit checker back in the '70s and the whole tube glowed. It's a cold cathode tube, isn't it?
You are correct!
It's interesting that Dave Jones just did a video on using similar pass elements in solid state supplies.
Hello Mr. Carlson, I was wondering about building a 1 tube guitar amp using a 6GF7A. Naturally, I'm thinking of using one half of the tube as preamp and the other output. Is this tube suitable? Thank you , William
Hi William. The 6GF7 is a dissimilar dual triode that wouldn't make very much power in audio service. If you wanted to use a compactron type tube, the 6LU8 would be a better choice, and provide some output power.
6bh6 tubes were very popular in fm 2 way radio receivers.
You are incredible just a gifted person, I wish on my best day I could be as good as you on your worst....lol
I am still having trouble with troubleshooting both tube and solid-state electronics. I read a schematic and there are both resistance and voltage values at tube pins, I check the resistance value it's fine but I can't trace the low or too high voltage readings. I use both a DMM and a VTVM so as not to load down the circuit.
Example would be at the #2 pin of a 6AU6, 47K / -9.0 vdc Could you do a video on correctly troubleshooting electronic circuits?
Thanks, Tony
Pretty good performance for something that was intended to be a home-built kit.
Nice overhaul, im sure it'll be a useful addition...Bit of an afterthought as you have already finished it now but assuming it was operating before you restored it it would have been nice to see a scope trace of the DC rail before and after you sorted the wiring out to get a visual idea of noise reduction through component / wiring placement.. An old timer I know just recently finished an 11 tube "all GT" MW/SW PP. The amount of experimentation he did with component and wiring placement was verging on OCD but it is one of the quietest sets i've ever heard, even at near full volume there is little to no percievable noise.
What is a practical uso of a potentiometer of that size? Is it for fine tuning the current in a welder?
OK. I'm in the process of restoring mine and it still has the two selenium rectifiers. Yours had them removed by the previous owner and a dropping resistor added. I got that much. (The schematic indicates 270 volts is correct) Your pre-restoration has the dropping resistor and the 1000 ohm resistor I see in the schematic. Your post-restoration only has one (3 watt?) resistor there, no 1K resistor? What am I missing? By the way, mine was factory wired and is really well done! Neat. Orderly. Thanks again!
Have you checked if the negative supply output varies depending on the position of the meter switch? The schematic makes it look like there would be a significant change doing that. Adding a zener diode can fix that.
Safety ground in the uk is TRUE ground, via a 6ft copper rod outside the house. Neutral is only connected to ground back at the transformer.
That safety ground sure wouldn't carry much current that way, (if it's just a rod pounded into soil.)
Thanks Paul! Nice power supply!
You're welcome Robert!
Thanks for this video! Any suggestions for the cause of the following issue? When I switch the supply turning on the high voltage ,I get a big momentary pulse of power that has actually taken out solid state devices in the hv path. Otherwise the supply works fine. thanks
Looking at the schematic, I see that it might have been a good idea to put a high resistance in parallel with each of the diodes that are in series. Something around 1M as shown on schematics for transmitting supplies in the ARRL handbook. I was thinking about what you said about the spike when turning the supply off is something that many of us never think about. I have seen what you said about capacitors blowing up when put into circuit backwards, They get hot really fast then blow out all of their liquid.
May I ask why you suggest running twisted AC lines to the chassis when working with point to point when I've noticed ever audio amp and guitar amp has them as far away from the chassis as possible. Even uncle Doug suggests to do so.
Hi Stefano. There is a lot of misleading information out there due to the lack of understanding AC, and AC filament systems. The chassis is common to the high sensitive circuitry, and acts as shielding. "High floating filament lines" are only common practice with remote tube sockets extended with wires from a circuit board or eyelet board. This type of build is common in guitar amps, "NOT" in High Fidelity applications. You will notice when you turn the gain (volume) up on a guitar amplifier with this type of circuitry (HFFL), they are far from quiet. Here is some good information right from RCA. Go to page 92 of the PDF (actual book page 90) and start reading "High Fidelity Systems." This is continued to the next page, you will find many of your answers there. Here is a link to the RCA manual: www.nj7p.org/Manuals/PDFs/Tubes/RCA-RC-27-1970.pdf
@@MrCarlsonsLab thank you kindly. I think I understand. However, when I watch guys like Terry from D-Labs and Uncle Doug, they suggest the HFFL method to avoid noise. Often boasting about the amp being quiet and adding that one of the attributes to this is the HFFL.
I haven't read the link the to RCA book yet. But I will do so to get a better understanding, as my lack of understanding as of now is making me believe there's a place for each type of filament wiring method based on the circuit design, nature and intended use.
So, is this why when I repair a more modern guitar amp with a circuit board, the filament connection is either on the board in straight lines, somehow avoiding any noise injection. Or like in some Orange guitar amps, the filaments are untwisted wire that's not exactly hovering high above the circuit board. I first thought it was maybe a DC voltage. But upon measuring, I was wrong.
More research is required.
Thank you for your time and details response.
Another excellent Video and very informative. Thanks for sharing it with us.
Great video as always