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You can replace the field coil with a power resistor and that would free up the power supply from the output stage. Than, replace the output transformer for one that has a primary that will work for the load resistance of the output tube (for this 6F6 tube it would be 7k ohms O.T. primary impedance), and a secondary that will work for a 4, 8 or16 ohm speaker of your choice. ;) Note: You can find the load resistance for any output tube in a tube specs sheet. It's easy to get them online.
At 19:00 the ripple smoothing coil functions as a DC fed electromagnet. Very clever to save copper but.... doesn't that creates a 120 hz hum in the speaker. It is like you mix the Hum with the audio. 2nd doesn't the audio on the other hand get fed back to the DC supply and into all further electronics again creating that sort of echo?
Your thinking low voltage / high current: solid state. Tube devices are high voltage / low current. That is a major mind jump! So as a tube device, what we have is this circuit in question (C17 Field Coil C19), which is a pi filter, designed to remove the low millivolt 60/120Hz AC ripple off the high DC (B+) line. Keep in mind that the B+ is up around 300-375V DC! The percentage AC voltage ripple, before the the pi filter, is 5V DC (the filament/heater voltage of the rectifier tube). That is 5vac/300+vdc = 1.67% pre-pi filter. Another way to look at it is: a B+ voltage of 300V DC would be a pulsation DC voltage of 300V +/- 7.07V = 292.93VDC to 307.07VDC. The +/- 7.07V is the peek to peek voltage of 5VDC (5 * 2.828 = 14.14v p-p = sign wave of 7.07p+ to 7.07p-). That is quite insignificant at 300VDC right? And that is BEFORE the pi filter. After the filter, the AC ripple voltage would be a much lower percentage. Perhaps as low as 0.001%. Which at 300V AC is definitely insignificant! Next we have C7 going to ground which the AV ripple would see as a "water slide to ground", while the DC would see an insurmountable wall of concrete! Lastly, the Output Transformer is driven by the amplified audio signal, superimposed on that 300V DC. As for the reflected audio back to the high voltage power supply, who cares? It would be swallowed up and grounded, through the center tap of high voltage winding of the transformer. Again, all these things would be serious issues in a low voltage, solid sate device. And much worst in an analog to digital IC circuit.
@@ElectroRestore so that Hum will be bearly or not hearable and the feed back audio wouldn't be of any significance to cause echo or refraction effect.
@@ON5ALE-Alessio Exactly! Each stage is pretty much isolated from the previous stage by the one-way signal path. On the RF side, you have high frequency filtering through the IF cans (455KHz for AM and 10.7MHz for FM). So feedback there not likely. If you have wires that are not dressed properly in their layout in the chassis. In such a case, it might be possible to get feedback in the oscillator circuit, which has high sensitivity. However, most of it would be stepped on pretty good by the incoming radio station and IF filtering. You would be more likely to get 60/120 Hz hum interference from the AC tube heater wires, if they ran over sensitive areas, than reflected audio signals. Very good questions! Thanks for asking them!
thanks so much for this very educational video.i have been trying for years to get started in diagnose and repair old radi o and this has renewed my interest.will look for that function gen app for my phone and give it a try. John
Thank you! I appreciate the positive feedback! Perhaps I will make a video on an AA5 using the smartphone function generator on the RF section to do an alignment.
I have older lab-quality gear on my bench, Agilent. Fluke, etc. But I'm finding that pocket-sized, battery-powered gear like the TinySA, the NanoVNA, and $90 pocket O'scopes are so much cheaper, accurate enough for most jobs, and far more convenient than 50 pound, multi-thousand dollar bench-top or rack-mount gear that I run the risk of blowing the front-end on the moment I do something stupid, that I'm always looking for cheaper, smaller, and more convenient ways to do things. You seem full of such ideas, so here I am. I'd never thought of using an old phone as a sig gen, certainly not a sweeping one with modulation for various modes. But what interests me mostly is how it generates IF's like 10.7 MHz from a headphone circuit, and how much higher it can go. I assume it's sending out a square wave and is using odd-order harmonics, but if it's getting that far up into the RF range it must be limited to that phone's chipset. Anyway, I'm curious about it, because any tricks for doing more with cheap, small, battery-powered gear I can carry around in my pocket is always a good thing, and after spending years gathering up a rack cabinet and test-bench of good, old lab-grade gear, I'm more than happy to let it gather dust on my bench while I use something on my desk, the kitchen table, or up on the roof that's the size of a pack of cigarettes but still does just what I need doing.
I could not agree more! I have a TinySA transceiver, a small battery-powered AM, variable frequency transmitter, that I can modulate with my phone. And an even smaller, not much larger than a 9-volt battery, FM transmitter, which works on a good number of preset, fixed frequencies across the band. However, Ireally enjoy the function generator. Perhaps I will make a demo video, showing it in action for diagnosis and AM/FM alignments.
I can't claim that I came up with this saying but you have got what is know as "the warm tube glow of victory". Great reception and it sounds perfect. Congrats Paul.
Over 200 Volts DC on those trimmers. Be careful man! I have a tee shirt with Reddy Kilowatt on it holding a knife to a young boy and it says "Remember kids electricity will kill you".
No, there is no pump. It is called a pour over coffee maker. Because you pour a pot of cold water in the top (when it is already full)and a pot of hot coffee comes out the spout.
My uncle gave me this electric screwdriver and I have no Idea about it's charging. My I know how many hours for it to fully charged and how do I know if its fully charged?
I really don't know. I just leave it on my USB charger when it is not in use. It still works great and can hold a charge for days when I forget to reconnect it. ;)
The new LCD type displays today are very bright! The 2.4 GHz frequency counter version has an 8 unit display over your 6 unit display but ironically seem to use the same IC chip. I think you have been misled as this unit actually only goes up to 60MHz. The 8 unit display goes up to 2.4GHz! The pictures shown are for that type not yours. Dang Chinese.
Yes, I later was able to switch through the hi / low frequency menu. It apparently does .1 to 10 MHz (almost) on low, and up to 60 MHz on high. On high setting, I can still get down to a solid 455KHz for most AM IF tuning and up to the 10.7 I need for FM IF. It will also do the AM/SW bands on antique radios for RF tuning testing and dial setting. But for $20, it is a pretty stable device. To be honest, when I bought this one a few years back, I did not expect it to be anywhere near this accurate. I will be upgrading to the newer one though because it uses more digits.
LoL I have had to do a few reworks that the capacitor queens got lose on. So many think " recapping" fixes everything . Then when it does not work they always seem to find there way to my bench. Great video. 👍
I have an early 50s mobilaire 4 blade fan where the motor spins clockwise rather than counter, so the fan is blowing air through the rear. At some point i read this is an easy fix, but cant find that article. What do i do to change fan direction so its blowing at you?
It is most likely a bad capacitor. Replace it and it should be fine. You might want to use one about .25 uF less than the old one with a higher voltage rating.
And here I thought it meant Surface Mount Device. Thank you for the video. When I was young and working in a TV/radio repair shop I kept thinking that the crackling sound was from the air-variable cap plates rubbing, but I could seldom ever see any shorting plates. But the sound I heard was the sound your IF can caps made, so now I know.
It can be caused by tin whiskers shorting the plates in the tuning condenser. I have actually had to use a strong magnifier glass to find and remove them. In regular variable capacitors, like trimmer caps, however, that does not happen. Because the mica chip is larger than the plates and no whiskers can cut through the mica to shorth them out. Glad you liked the video! Thanks for the comment!
You don't want to start with the slugs at centre of the coils, that would be Max inductance you want them to be half way so you can either increase or decrease the inductance.
@@ElectroRestore No, the centre is half way down the length of the coil but the centre position is max inductance, with the slug in the centre you have max ferrite between the coils, with the slug at the top or bottom you have min so if you want a position of being able to increase or decrease frequency you need to be between the two.
@@stoptheirlies You are correct. The only way to increase or decrease the inductance, is to be either 25% down from the top, or 25% up from the bottom. That would be the center of the range rather than the center of the coil. I am use to tunable capacitors in antique radios and so it really would not matter if you was at max impedance because you tune with the cap values. For slug values (without SMD) I would just adjust for resonance with the slug and not worry about start or stop position.
Look forward to the flow-on videos! I see an ohms on the schematic: 0.6 ohms and 9 ohms; what are those? Resistance of the coil or the impedance of the tank?
@franzliszt3195, Yes they are the DC resistance of the coil wires. They are low because to DC, the coils are like just any other wires, only much longer. So they have some resistance. The IF transformer makers included them to their customers, because the anticipated failure would be an open or a short in the coils themselves. Measuring the resistance (DC ohms) should be in that ballpark. They did not supply the capacitance in most cases because they did not foresee any real chance of failure there. Great question! Thanks for asking! I will be uploading another video in this series soon; hopefully in a day or two!
@@ElectroRestore thank you for the response. It is seldom that anyone makes what may be called a ‘definitive’ version on a subject. Most only go very a partial answer.
I will never forget the video that Dan Yahro aka Shango066 put out years ago showing the light flashes from inside the bottom of an IF transformer from silver mica disease. His cure was putting small trimmer capacitors across the removed mica plates and adjusting to get a balanced results. Was a long arduous process to say the least. Eventually replaced with silver mica capacitors which are very stable, precise valued and reliable capacitors. Sadly most manufacturers never do show the capacitance inside the cans in a schematic diagram which would help a great deal there. The primary of the IF transformers are connected to B+ and the secondary to B-, and not ground usually because the metal case is at ground. Good tutorial so far Paul.
Yes I loved Shango's video! I had a lot of experience with SMD. However, I never actually seen it arcing like that one was! You are correct, I should have said B- rather than ground. It is held above ground by that resistor on the secondary side. I was more trying to contrast the potential differences between secondary and primary. Dan's video documented just how much potential difference could exist in SDM to actually jump across such a gap. Thanks for your kind words Steven! I appreciate the support you have shown my channel; now and in my earlier days!
Model 12H092 with chassis 11C21 from 1946. What a monster to repair. They still had the rubber coated wiring that was used in prewar models. It was crap stuff but still used until it was gone from their supply. I bought the Zenith Service Shop Notes on CD from a guy called redstar22 on a popular selling site. Clear images than free ones online. It's good but you need to know the model of phonograph to see Zenith service notes of it. (S-11680?) Glad to see someone else has got that stuff covered. The coil in a Radionic cartridge can be tested on lowest Ohm setting on a meter. If it is good it should read 3 Ohms or about that. You could have dirty contacts if so wipe them down with alcohol or Tarn-X and try again. If you still get zip the coil is open. Seeing someone else show all this helps tremendously Paul . So thanks! Steve from IL
Yes, it is a fun one for sure! You are correct about the phonograph that was installed with it. It is the S-11680 model 78 player. I already rebuilt the motor and still working on recapping the main radio chassis. I love a challenge and this unit has been that! Thanks for the comment Steven! - Paul
That depends on many factors (current draw, phase angle, capacitor/coil values, age, lubrication, bushing/bearing condition, stator condition and hours of usage). Generally, it can range from 600 RPM or so on low to 2K RPM on high. What you need to be concerned with is current draw being less than or equal to the motor’s stated current. And the housing should not get hot to the touch after running.
I'm an amateur and I have restored several radio's, tuners, tapedeck and a grundig 2355 tube radio, just for fun and hobby. So it is possible. The person you are talking about in the video was not an amateur, but an overestimating novice with no feeling for components and how to solder them correctly.
Thank you for this video. I've learned quite a few things. I wonder, if one wishes to restore such radio to working condition, and finding one of these old speakers is impossible (let alone rewinding the field coil), would it be possible to instead use a modern speaker with a permanent magnet, and any kind of inductive 1250 ohm load on the ripple smoothing side?
As long as the inductor can take the high voltage, yes! But I do have a video showing how I rewind a field coil. It really is not that hard. Actually, you can repair them if they are not too bad by replacing bad spots. If just the speaker is bad, you can put the field coil in the cabinet (if the original one is good). Assuming there is room of course. Then install a permanent magnet speaker.
You could try oil and heat. Try to get oil to run down behind the blade support, where it slides over the armature. Let it sit a while with gravity pulling it in the gap, possibly. Then add more oil all around the shaft, and apply heat to the blade support. Keep moving the heat around the joint to make it swell so the oil can seep in. Lastly, do all the above on the set screw hole also. Never apply too much heat. Just get it hot so it expands. Then try and take the screw out again. If no luck, you have no choice: drill it out and re-tap the hole for another (larger screw).
You may be a professional in restoring electronics, but you are a rank amateur at making videos. This video is _literally_ sickening. Camera tripods are not that expensive.
It's a lot of extra work when the customer has installed Parts incorrectly or to the wrong connections because you have to trace point to point everything on the schematic to what's on the actual physical radio. It's a much more involved repair than just repairing something that failed what but was not touched by the customer.
Well, the only way you'll learn is to do it yourself. As you get better at it you can go back to earlier work and re-do it if it needs to be re-done. That is, assuming you own the radio and are doing it for yourself. There are still lots of things I'm unsure of, but that doesn't stop me from trying and learning. I've never had a set I've given more than $100.00 for and most were picked up for far less. The most expensive one I've had so far is a Transoceanic that I ended up giving to my uncle as a Christmas present. When you've grown up and live out in the sticks like I do there isn't much opportunity to work with a repair technician. My Pappy did work on electronics when I was a child, but I had absolutely no interest at all in the hobby back then...especially after he picked up a truckload of tubes and we had to spend days and days sorting them all back in about 1982. By 1989 all those tubes went to a landfill as with no internet or anything else at the time there was no way to gauge that they'd ever be worth anything in the future. Of course, hindsight is 20/20 and when I did finally gain an interest it was far too late for any equipment that my Pappy had once had so I basically started from scratch.
I really enjoyed hearing of your upbringing with electronics,. It brought back memories of my childhood being taught by my dad, who had a TV radio repair shop. I wish intensely, that more young folks were interested in learning to repair these devices! It is sad that not many have your zeal for learning it! The issues is not that they shouldn't do it till they learn how. It is the dangers of learning on a transformer set that sources out upwards of 600-700 volts AC ,and 200-300 volts DC to the plates of the tubes! One wrong touch, in the wrong way, and it's an all expense paid trip to harp land! Also, these devices are getting rarer to find that are not botch by bad service work. What I suggested was that folks learn on All American Five (AA5 and AA6) radios, which do not have high voltages, are cheaper and more plentiful, and easier to rework back to specs if a restore is badly done. You can stirp them to the chassis if needed, and try again, and learn much doing so! Safety first, skills second, expensive and rare device should be last. You have to learn to crawl, before you learn to walk, right?
@@ElectroRestoreI'm 25 now I've gotten a few sets going so far noticed I said going my first was a AC/DC 5 tube zenith my brother got for it was already " cheaply repaired" from the eBay seller a cheap Taiwan no name filter cap. With the ground end crimped to the aluminum can of the filter cap, upon receiving the radio and opening it uo the ground had broken rigth at the crimp, the one mica that would of be in circut of the oscillator to the mixer was changed or replaced with a capacitor tolerance 20% not the 5 % that it should be. The radio has been used for some parts as it was in great shape externally. Wound up building a two tube regenerative receiver based off mike1 I think that's the correct portion of his user name on RU-vid I'll edit it correctly. Any how his design was intened for lower b+ im essentially using his circut to but at a higher b+ the oscillator coil has had some turns removed, now I think I'm gonna redone the resistors. Really fell in love with this radios since then. Got me a vtvm,an eico which was in pretty good shape extrenaly electrically the whole voltage divider was 10% or more out of tolerance so got. Got really good 1% resistors from mouser
@@Anthonytheredneck It sounds like you have quite an aptitude for vintage electronics! Thanks for the comment! It blesses my heart to hear that younger adults are still showing an interest in tube radios and the like! I have tried to find an apprentice around my area, with a basic skill aptitude but with little luck. It may just be my area idk. If you start a RU-vid channel, be sure to comment and let me know and I will subscribe. :)
@@ElectroRestore I've thought about restarting, lost my old account a whlie ago do to the sercuity set up. But I think it would be wise as my work ethic is handled a bit more seriously, I work on soild state too, actually were I statred doing first. Being already mechanically inclined at the time and you tube pretty much just came to be about 3 years after RU-vid started. 30 watt iron and scarping old boards for their parts like transistors and the wire and so on. Gosh i let the smoke fly doing stuff like that. Much older and it didn't really take long to comprehend how circurts kinda work.
I used to use an eraser just like this in my drafting class. Ours was working like a champ well into 1994. We used to take the caps off our drafting pencils (which hid the eraser) and put them in the chucks to drill holes in things around the classroom. Yes we were mischievous.
I think I turned it to much the first time and tried to turn it back, now I’m not sure where I started from. Any way to get it back to factory settings to start over? Thank you
You can't buy SPDT (OFF ON ON) switches these days. If fact the switch I used here, I bought from Granger. It is a Carlton switch. Stay away from them! I had to buy 3 to get one that worked. You usually have to get a SPTT rotary switch: OFF ON ON ON and tie the last two together (OFF ON ON ON) or cut the last wire away (OFF ON ON OFF),
Mine leaks horrible from the top. Took it apart and it nearly flows out of the thermostat washer that is like brand new. I probably going to seal it with some food grade sealant.
mine went wild and started gushing water out of the filler and sprayer im guessing the thermostat messed up. I replaced the thermostat and it works but seems to not get as hot as it did yes I have it all the way to hot.
You should also change the cutoff switch. If the water gets too hot, it will boil over and spew out wherever it can. Also, the silicon gaskets on the tank lid should be replaced. One was replaced with your thermostat most likely. Check the other too though. When they get hot, they expand and loose their tight seal. Boiling water will destroy their integrity.
Hey, myn leaks from the tank top when I dump water in it. I'm guessing I need to change this seal? Also my machine sits in my cold barn. Anything I should do in winter time? Will it break if it's full of water? Thank you
Change the tank lit gasket and it should be fine. If it freezes full of water it can split the tank. However, it is more likely to pop the gasket and bend the lid.@@tonyb3676
Este mismo ventilador, en mi pais Argentina, lo fabrico la empresa Siam (compro la patente a Westinghouse) y es un fierro muy duro noble e irrompible al dia de hoy sigue trabajando todos los dias de verano en casa, como amante de las antigüedades eternas sin obsolescencia programada es un producto al que le tengo mucho aprecio, por eso llegue a su video, saludos.
Very interesting. I did not know Westinghouse sold the patent on this fan. Glad for you that they did! Sounds like you got to enjoy this awesome fan for many years. Thank you for sharing this history with us! It is always fun to learn what happens to these things when they are no longer available in their original place of origin.
@@ElectroRestore es una reliquia, y lo sigo usando, acá estamos en verano, de hecho hace un día, compre uno de piso industrial de la misma marca de aca (Siam) pero de una patente también comprada a Westinghouse, genera tornados ese
actually that speaker is not so bad compared to a really busted up speaker cone. I have used audio exciters before to replace a voice coil. The exciter needs to be mounted to something rigid like a large speaker dust-cap. In this replacement assembly, the audio transformer is used to drive the (4 or 8 ohm) exciter and the field coil is used only as a choke.
