What a fantastic video! Watching your diagnostic thought process unfold is an education in itself. Superb. Also, there aren't many videos amongst the hundreds that I watch on KZfaq that make me laugh out loud, it's added bonus content, your cat is hilarious.

Another electronics detective story. Thanks 😊 Bloody hell, even the sidekick cat makes an appearance. Awesome! 😁

I agree with your assessment about fake dirt and rust on items on restoration videos, DGW. I’ve dealt with plenty of old rusted and dirty parts and they never look so perfectly and evenly dirty as in those videos. I’ve long been suspicious but never heard anyone voicing the same view.

Yes we still watching , please continue & thank you for your nice analyses .

You bet we are still watching! Thank you for taking us along, very nice video!

This guy is trusted and knows what he is talking about.

I have learned soooooo much from watching your channel. I've watched you from 40K+ subs, and so happy for your growth. I really appreciate the honesty and the no behind the scene games for video setups, just good content, mistakes and 2nd guessing and all. Thanks for all you share..

5:52 - there should be a bushing between the PCB and the meter's screw terminal. No wonder there's no contact or intermittent one. Fortunately fixed (you can see it at 6:14). I like the way of converting a vertical cap to horizontal with a piece of kapton tape. It's a nice one - gonna put it to a good use :). Nice boards, all hand routed as it was done back in the day. Now I want to make a 723 and KD503 based dual-ganged symmetrical PSU at 0...25V 0...3A, with an adjustable current limiter. That would be a nice addition to my lab, but first I'd have to think of a way to do a coupled voltage and current adjustment. I was thinking in lines of a multi-turn pot first, but I'm more and more drawn to rotary switches for coarse adjustment and a dual-ganged pot for fine. Your bridge rectifiers don't sound too full :D

Funny, "If anybody's still watching.." 😂You know darn well you're way too humble, so grab some of that fire extinguisher and put your feet up!👍 Watching you work is always awesome!

Všichni koukáme, ani nevíš jak dlouho jsem se těšil na tohle video. Když si ho vydal řekl jsem si "no konečně" 😄😄

In the next video I'd be interested to see the oscillations caused by the having the full resistance of the pot in series with the capacitor!

TOP QUALITY CONTENT! Like and eagerly waiting for part 3.

vcelku zajímavé srozumitelné video

You just blow my mind on how easy you find your way around these boards and schematics. It takes me a while to get my bearings right. Good on you.

Still watching and looking forward to the next journey Daniel! Thank you for the great video!

Wow... all those old transistors.... I've got none of my childhood salvage left but I do have stuff out of the rubbish at work from 1990.

Thanks DGW, been waiting for part 2. Perfect evening viewing ❤

Velmi se mi líbí ta tyristorová předregulace. To jsem ještě u zdroje neviděl.

Nice video.... Thanku for second part 👍🏻

tbh i'd be watching your videos if the were hours long. i work in electronics engineering and this is basically entertainment that doesn't let me go full-on couch potato like the tell-lie-vision does

Danke!

I found a trashed crt television and I ripped the back of it off and took out the circuit board. It was LOADED with capacitors and resistors. I now have a collection of the electrolytic caps (the biggest being my favourite)

Thanks for a very interesting video. Very satisfying to fix a device that has been faulty for a long time.

Another great vid. Thanks Dany!

Really enjoying this series, keep going.

Loving this series!

very nice Video, looking forward the next episode about this power supply.

We are still watching. 😀

Cool and informative.

I am thrilled about the next episode, nice like always, yes I am still watching till the end, thumbs up

Great show!

I'm glad that I'm not the only one who managed to blow up the tester by accidentally charging a capacitor and then sticking it in :D

I love how there's a ZAP button. :D

Really great video. I always learn a lot from you. Keep up the good work!

Yes I'm still watching ;)

As far as I know the fixed voltage section does not work like a current limiter, but it has something like overcurrent fuse. If you increase the current, it goes up to 1A/2A (depending on the voltage) and then it trips and the current fall down to some hunderds of mA where it sits until the load is removed from the PSU's output. This is how it is intended to work. Calibration process of this requires variable load and is somehow tricky. Regulated voltage sections could be easily modified to behave exactly the same way. That potenciometer with failing wiper is intended to compensate oscilations of the regulation loop and it should be set right to the edge of stability, which would provide the fastest reaction of the control loop. This should be adjusted using oscilloscope observing the reaction to the rising and falling edge of the step changing load. If you have nothing, that could vary the load in steps, you can also adjust this to the point, where oscillations of the output stops and does not kick in after powering the PSU down and up, but this gives less precise adjustment making the loop to behave a little bit lazy and conservative. Adjusting this on the voltage side of regulation is similar to the current side, but the output voltage change is excited using the external cotrol port on the back of the unit. This is the easy part of it, it just requires just a pulse generator. Maybe, there is possibility to excite the current change same way using the external control port, but I didn't try doing this that way. And, as I look at the behavior of that regulated channels, you have the issue with the 120Ω instead of 100Ω wire potentiometer in the +3V continuous regulation. As I know this affects all units made by ZPA, the original Aritma units (TSZ75) did not have this issue. They was unable to obtain a 100Ω wire potentiometer, so they used 120Ω instead resulting in that the +3V position of the continuous regulation in fact adds about +3.6V, which is annoying thing, because the scale around the knob does not fit. This can be easily fixed by adding some paralel resistor with trimmer to that 120Ω potentiometer adjusting it to fit the scale at +2V position resulting to the reasonably fine corelation between the scale and the output voltage. This is an easy fix of something, that manufacturer horribly screwed past in the 80's. In fact, after fixing all faults and adjustation it is a decent PSU with an high (not precise) accuracy on the fixed voltage section, the regulated section is far less accurate, but still reasonable. These PSU's are not easy to fix, but until that huge transformer blows up, they are at least fixable. When it comes to adjusting it, this PSU is a beast, it takes a long time, but it makes sense to undergo that process.

I'm glad to see your little sidekick 'Meikhat' is still guiding you along. I haven't seen him in a while! That's an interesting little project you have there, and not really in my field of experience, so even more interesting in that respect. I think you'll make a 100% success out of it. It'll be interesting to see how it performs when called upon to do some work.

way to go, awesome. Look forward to your video drops. Thank you. From AU.

thanks was great fun

Very interesting! Once I saw those old potentiometers, I taught "I wonder how good those contacts are". I would say it's a poor design that the current limiting stops working because of a bad potentiometer though (if connection get poor in the potentiometer contacts, the current should drop toward zero, rather than increase uncontrollably - since that can cause damage in some cases). I know also from building preamps for my recording equipment (that I use for example for the audio on my KZfaq clips) that potentiometer contacts tend to wear out or oxidize after some time. In that application it's very sensitive, since poor contacts will cause terrible noise into the audiosignal and onto the recording (even before it causes the resistance to go up significantly). So after getting way too many recordings ruined by that, I have changed to just using a rotating switch that adjusts the gain in steps thru fixed resistors, rather than having a potentiometer.

Great Video!

Yay a part 3...

i love your cat in these videos

Thanks

Put slightly better heatsinks on the heatsinked transistors. One thing to watch is the overall height as the boards are plugged in one behind the other. The collector is usually connected to the case on most metal TO18 and TO5 transistors.

Nice video.... Thanku for second part 😂

Very interesting

Mr Wild, I watched all the way to the end so at least one (1) person sat through the entire video. I'd like to see you repair an HP8566B spectrum analyser next, maybe even convert the CRT to LCD - I'm not sure why though, I just think it'd be interesting.

It is very interesting!

Nice.

I am still with you☺

Interesting. I like vintage technology. You can fix it.

I waiting for part two, greetings 😀.

Nice! I love that thyristor circuit, never seen it before yet it's such a neat idea! I wonder why it's never used today? Maybe for the cost and complexity of driving a thyristor back then you can just instead drive a full SMPS today? I'm guessing the switching noise is probably a no go for many linear devices today? Or maybe ZPA Košíře had a patent on it or something?

Gotta love the cat tax

lmao at "throwing kittens into the sewer"

Yes, i'm interested. I want to bulid PSU with a thyristor regulation in it

You did well to make sense out of that madness. What a shame your "Transistor tester" had a shock, but i think you have built a far better cap/esr tester anyway....or i might be getting mixed up with your battery capacity tester. What about getting the code and an atmel chip, maybe its cheaper to get the whole tester again. I have one as well, not perfect but better than a kick up the ass lol.

I want to see oscilations on osciloscope and the middle section fixed!!!

I also repair an age old power supply by changing faulty potentiometer

Thanks for another great video! I've been bingewatching all your videos on the last weeks and its been super educational and sometimes really funny. Your cat didnt jump on the table this time but he always giving funny comments :-) if you want i can send you a free very nice japanese 430mhz ft480 yaesu hamradio transceiver from the '80s, broken ofcourse. 73 on5gs

Danke! Most Thanks so Far as i see XD As other Guys in their comments said: Voltage Preregulation with Relays and multiple transformer tabs is known... But never heard about thyristors as preregulation. So i'm highly interessted in the next Episode of fixing The middle section The proper oscilloscope pictures ( my oscilloscope is this well known red chinese 25€ one) And more surprises Really surprised about this faulty contact of a Potentiometer!! O.õ Second Thanks for another almost BloodY long Video ;-p

I blew up the same component tester exactly the same way....🙃

capacitors of that vintage used inert electrolytes so don't internally rot like modern water based designed to fail ones. (notice the leak has damaged the plastic cover not the metal) old capacitors would cost 5x as much due to the magic electrolyte but late 70s the new chemicals made them cheaper to make and last 'the life of the product'

Please fix the constant voltage section as well. Would love to watch that.

I blew the same capacitor tester like you, with charged capacitor

❤️❤️❤️

2:25 - Does this leakage tester operates similar to Mr. Carlson's one? Do you have a video about it or it's schematic?

I used to admire those pink Tesla capacitors - they looked so more modern compared to the bare aluminum Soviet and Hungarian ones

I am watching and I also watch the spark gap tesla coil & solid state tesla coil series and also dangerous charger series

🇧🇷🇧🇷🇧🇷🏆🏆🏆 Nice work!!!

Cat goes behind the door for criticising the solderiiing.

Jewel great

Tato anglictina patri do odkazu svetovych dedictvi. Posusnani.

I blowed multi tester by charged capacitor too 🙈

I have a vintage drum mashine from the past and would like to re-cap it. It has 0.47uf & 2.2uf 16v capacitors but I can only find 50v versions. Is that my best option? I do not have tools to test capacitors and would like to replace all them all.

4:58 jak przełączałeś lewą sekcję to trzaskało w głośniku

try dc voltage controlled ac voltage capacitive c-cr division voltage regulation, not shunt regulation with diode full blast only

Bladi long video xDD good job

It always fascinates me how technology have gone over the years for example the MiniWare power supply is more or less 10X smaller than this and can output more power

I'm restoring a vacuum tube signal generator from 1960s and the electrolytic and paper capacitors have leaked and are showing completely different values. Do i have to replace them or is it ok to turn on the device with the capacitors being a few percent off? I don't want to destroy the device.

Myslím, že růžová izolace na elektrolytu byla sežraná molem. Typické piliny od mola.

what does the cat do.....is it your mentor......! ‌‌!!!

Old Soviet part have so much character. I hate smd components because they have no character and look like braille dots.

Looks more like bug poop then electrolyte

Interesting fault. Sort of an odd power supply with no voltmeters.

Aka Odysee - Super-Grand-Ad - LIKE 09 - Video 3 Please.

Danke!

Danke!