You really take me back to the past with these radios 📻. Car 🚗 radios 📻 are NOTHING like 👍 they used to be back then. Just a junky hunk of plastic. That’s also true to most radios 📻 today. Your friend, Jeff.
Ha, thanks. Have given a couple engineering lectures with attendees including NASA folks, including at a university masters program, and those NASA engineers were some of the smartest, and most insightful and friendly folks I have met, so I am humbly honored by your comment.
Glad you enjoyed it. What I am doing: in that series I am electrically restoring a 1953 Chevrolet AM car radio, with vacuum tubes, for a fellow's 1953 restored Chevrolet classic car. There was an old defective capacitor which needed to be replaced, buried under tar, inside the transformer can, for the radio's power supply. Thanks for watching and the comment.
You opened up a can of worms on this project, nice work on getting rid of that leaky capacitor. I would think the old vibrator with the contacts would be noisier than the solid state vibrator.
I'm sure glad you took the can apart. I wanted to see what was in there. I have a square power transformer can that rusted out 1 corner , in a junk car (with no windshield) reason for rusted corner. I listed to the sound trying diff caps near the end of video Iliked the black &blure cap 1000 uF 35 V the best thta came with it > keep up the good work & taking the time record it.
The 0.8uF capacitor has quite a high esr a high frequencies. The low pF capacitor to ground makes up for this. It's value is optimised to reduce noise at the Radio Frequencies. The electronic vibrator is probably quite different noise character to the original🙂. Nice job.
I took one of these radios apart back in the day (don't worry, it was not in that great condition.) and saved all parts from it, and I used the transformer to make a homemade vibrator power supply for a military radio set from the second world war. Mine was the same model, at least I am pretty sure of it, from my father's beautifully resto-modded 53 chevy which also happens to be a 210! (the radio could not fit in the car any more as we wanted air conditioning more than we wanted a radio.) but I ended up taking it apart, reusing the vibrator and transformer. I also made a little tube amp with the audio tubes from it, the reciever tubes got used to restore another fairly nice tube car radio :) I had no idea there is a capacitor inside the transformer itself, I never bothered to look up the schematic for it since I was taking it apart... It has been running for many hours though without issues, and since that capacitor only sees low voltage I personally won't take mine apart to replace it. The worst that could happen is that it shorts and then the high current 6V will just blow it wide open. Still very interesting! might be worth checking for capacitors in my restored vacuum tube car radios too, I have a obsession with them haha. I even like taking the vibrators apart and cleaning them and make them run again, I enjoy the buzz they make and so far my restored vibrators have been working beautifully, I have put many hundreds of hours on them and they are not showing any signs of wear :) It's all about the buffer capacitor value on the high voltage side of the transformer, it's always worth experimenting with the value with the vibrator opened up to see which value gives the lowest amount of sparking - I find that a lot of times they used what was available to them when they built these things, and sometimes a modern capacitor with a slightly lower or higher value can actually lessen the contact arcing even more! Cheers from Sweden!
Hello Sweden from Texas! Thanks for the comment, that's interesting how you have reused the parts. We considered leaving it in there, like I said risk/reward. If we could get it out, then we won't need to worry about over heating the transformer case and then blowing a fuse. But if it was so glued in there I could not either get it off, or get to the cap in the tar, we would leave it and take our chances. Happy we did as it was literally coming apart in there. If you saw the Chevy 210 this was going into though you would see why we wanted to fix as much as we could. Tack!
Back when autos had points and condensers you could often hear the whine through the speakers. It usually meant that capacitor inside the distributor was failing. The addition of a capacitor here is to provide a capacitive reactance to high frequency spikes of AC put out by an auto's generator or alternator via the "A" lead on the schematic. Here you can find the old wax paper one and replace it with a 0.47uF if you wanted to. Physically is must be outside the windings of the transformer and connected to one side of the inductor (be careful there) and shielded with the transformer to ground. If you have put in an electronic ignition (like many old car guys do) you wouldn't need the capacitor inside but the one you replaced with another value did the trick.
Thank you for that information. Oh yes I recall the whine. I added a Radio Shack choke to my power line in my '67 Chevy which seemed to have worked fine...thinking back 45 years there. Of course over the years I replaced the points and condenser many times. Yes this '53 Chevy does have electronic ignition and electronic voltage regulator too. It is planned to put a cap on the generator as well. So if this did not have the electronic ignition, we would need that paper cap replaced with another and put inside the transformer can? We could not take care of the generator and ignition whine before it gets into the radio? Thanks again.
@@PracticallyFixed Answer to question 1 is yes. Answer to question 2 is maybe, with the capacitor put back as a back up. You took the trouble to open the grounded box around the transformer to seal up any interference but I would have put a .47uF back inside to complete the LC filtering in this circuit. It was necessary back then when the car was built. Modern electronics like alternator to replace the generator and solid state ignition will mean it was no longer needed.
Greetings: Paul Carlson of "Mr. Carlson's Lab" had a similar transformer with two embedded capacitors. He acquired a retired oven-toaster from a thrift store and cut a hole in the top to permit nesting the transformer on the cut-out with a substantial portion inside. it will be smelly. So outdoors is likely a good idea. I think his transformer had a boxy shape where he opened the top to both watch the tar melting and remove it when "cooked". You may need to remove any end-bells and position a capture pan beneath to catch the melted tar for reuse. You may need to improvise a support while heating. You need to monitor the melt to remove the heat before any exposed portion of the tar-free transformer is burned. The capacitor should be found and removed. An external safety cap can be sustituted, while the transformer is retarred. I know it's a mess. The retarding process needs to be planned for ahead of time including any connecting-wire replacements. When done, you will feel very accomplished and tired. The cap was part of the mfr of the unit; one less part to add later. The tar should have reduced its needed size due to its heat dissipation ability. Hopefully, you will find and correct the cause of the excessive current consumption before it happens again.
Hello James and thanks. Yes I saw Paul's video and hoped that I would not need to heat up the unit to extract the transformer. As you can see in the video, the dried up and leaky cap was right on top luckily, under a very thin coat of tar, and I was able to remove it without removing the transformer from the can. Thanks again.
Hey PF, not sure I follow the rational of removing that part of the circuit. Maybe I wasn't listening close enough, but not knowing exactly what this radio will be used for, I can't help but wonder if that was part of the suppression of the contact points and/or generator noises. I think I would have soldered an insulated wire to the end that went to the center tap and ran it out through a hole in the side of the case so that you could replace the cap if needed. Then again, maybe the spark gap caps you were talking about after the transformer work are enough to deal with that noise. If I had to guess, I would say they all work in conjunction with one another to filter or suppress that noise. Just my guess. :)
Hi Doug. Thanks for commenting, so I will clarify what I was doing there. The capacitor inside the transformer was no longer filtering much of any noise due to the high amount of leakage it had. I believe the previous restorer found the noise due to that cap to be a problem and as a result mounted that blue Xicon 1000uF electrolytic cap on the power line going into the transformer, next to that spark plate disk. In an earlier episode, I had removed that Xicon cap to see if it was needed and it was indeed, to control noise. What perplexed me was 'why was it there' since it was not on the schematic. When we found the disintegrating cap inside the transformer and measured how leaky it was, answered that question. So instead of removing the old capacitor from the transformer (he may not have known it was there, or didn't want the hassle), he effectively mounted the Xicon capacitor in parallel to the leaky one. Meanwhile the waxy paper cap continued to deteriorate. The heat in the transformer, to which the leaky cap was beginning to contribute, caused the wax to melt and disappear causing the cap to fall apart when we touched it. It was a crispy critter by the time we got to it. So what we did here was remove the old capacitor from the transformer, and replaced it with a film cap of the correct value, in place of the Xicon. Since the spark plate disk had such low capacitance compared to the .5uF cap we were moving, I do not think it was forming a Pi filter of much effectiveness anyway. So whether the .5uF cap was inside or outside the transformer would not make any difference. So as you pointed out, if it is there for filtering the generator or points, etc. if could be mounted either place. Therefore I mounted it outside. The transformer naturally gets hot so no need to subject the cap to that service environment, plus if it ever needs to be changed it is easily accessible. (Spark plate cap: it is possible they are there to handle a voltage spike like a lightening suppressor on an outdoor antenna wire entering a house - the voltage would jump a gap and let the surge go to ground. Something which those early cars seem to have to deal with was static charge building up, apparently from the tires. The Chevy radio shop manual talks about adding static eliminators on the wheel hubs and also adding anti-static powder inside the tires. I read on a forum recently that the modern method of making tires makes that no longer such an issue.) So I hope that explained that I actually did not remove a circuit intended to be there, but did (re)move a bad capacitor from inside the transformer to a good capacitor outside. It is still on the power line to the center tap, bypassing to ground. In the meantime I removed the paralleled blue Xicon which I viewed as being a band-aid. Thanks again!
@@PracticallyFixed No, I understand what you did, but my point was it is impossible to put the circuit back like it was without having access to the lead on the end of the internal cail that goes to the tap on the primary of the transformer? Maybe from a DC point of view it might not matter, but it seems to me that someone had a reason to wire it in as it was originally. :)
Hi Doug. Why was there a coil of wire in the transformer can too? I do not know other than perhaps the engineers wanted a stocked design which could also work in other applications. I saw it also in other DELCO auto radios from that era. Also checked out a Philco which did not have it in the can that I could tell. There are other coils of wire (without cores) inside the radio chassis as you can see, one for the in-coming DC supply and the other going to the heaters. On the parts list the ones in the chassis we can see are termed "hash chokes". So there is already one of those on the DC supply to the transformer before the cap we added. As you say, it is a DC supply line, intended to be clean with little noise, and other than possibly forming part of a Pi filter, I could not think of why it would matter in a practical sense which side of the tarred coil the capacitor was mounted, and tested it accordingly. So regarding if it mattered, it does not seem to after testing showed it eliminating the line noise. And there was a lot of time this radio ran afterwards without a problem. If there is a problem when put into the car, I will report back. Thanks again. (ps, after that earlier reply I gave you I did a little research on static from tires in the 40s-50s - get this: they talk about going back to some of the earlier methods of making tires so they Will generate static electricity and using it for providing battery charge for EVs. What's old is new again.)
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You really take me back to the past with these radios 📻. Car 🚗 radios 📻 are NOTHING like 👍 they used to be back then. Just a junky hunk of plastic. That’s also true to most radios 📻 today. Your friend, Jeff.
Beautiful work. I love the attention to detail and the intuitive process. Your work would be an asset to NASA for certain!
Ha, thanks. Have given a couple engineering lectures with attendees including NASA folks, including at a university masters program, and those NASA engineers were some of the smartest, and most insightful and friendly folks I have met, so I am humbly honored by your comment.
I have no idea what you are doing or how it works, but it is fascinating to watch! Thanks for sharing! Liked and CONNECTED!
Glad you enjoyed it. What I am doing: in that series I am electrically restoring a 1953 Chevrolet AM car radio, with vacuum tubes, for a fellow's 1953 restored Chevrolet classic car. There was an old defective capacitor which needed to be replaced, buried under tar, inside the transformer can, for the radio's power supply. Thanks for watching and the comment.
You opened up a can of worms on this project, nice work on getting rid of that leaky capacitor. I would think the old vibrator with the contacts would be noisier than the solid state vibrator.
True. Thanks.
I'm sure glad you took the can apart. I wanted to see what was in there. I have a square power transformer can that rusted out 1 corner , in a junk car (with no windshield) reason for rusted corner. I listed to the sound trying diff caps near the end of video Iliked the black &blure cap 1000 uF 35 V the best thta came with it > keep up the good work & taking the time record it.
The 0.8uF capacitor has quite a high esr a high frequencies. The low pF capacitor to ground makes up for this. It's value is optimised to reduce noise at the Radio Frequencies. The electronic vibrator is probably quite different noise character to the original🙂. Nice job.
Thanks
I took one of these radios apart back in the day (don't worry, it was not in that great condition.) and saved all parts from it, and I used the transformer to make a homemade vibrator power supply for a military radio set from the second world war. Mine was the same model, at least I am pretty sure of it, from my father's beautifully resto-modded 53 chevy which also happens to be a 210! (the radio could not fit in the car any more as we wanted air conditioning more than we wanted a radio.) but I ended up taking it apart, reusing the vibrator and transformer. I also made a little tube amp with the audio tubes from it, the reciever tubes got used to restore another fairly nice tube car radio :) I had no idea there is a capacitor inside the transformer itself, I never bothered to look up the schematic for it since I was taking it apart... It has been running for many hours though without issues, and since that capacitor only sees low voltage I personally won't take mine apart to replace it. The worst that could happen is that it shorts and then the high current 6V will just blow it wide open. Still very interesting! might be worth checking for capacitors in my restored vacuum tube car radios too, I have a obsession with them haha. I even like taking the vibrators apart and cleaning them and make them run again, I enjoy the buzz they make and so far my restored vibrators have been working beautifully, I have put many hundreds of hours on them and they are not showing any signs of wear :) It's all about the buffer capacitor value on the high voltage side of the transformer, it's always worth experimenting with the value with the vibrator opened up to see which value gives the lowest amount of sparking - I find that a lot of times they used what was available to them when they built these things, and sometimes a modern capacitor with a slightly lower or higher value can actually lessen the contact arcing even more!
Cheers from Sweden!
Hello Sweden from Texas! Thanks for the comment, that's interesting how you have reused the parts. We considered leaving it in there, like I said risk/reward. If we could get it out, then we won't need to worry about over heating the transformer case and then blowing a fuse. But if it was so glued in there I could not either get it off, or get to the cap in the tar, we would leave it and take our chances. Happy we did as it was literally coming apart in there. If you saw the Chevy 210 this was going into though you would see why we wanted to fix as much as we could. Tack!
Back when autos had points and condensers you could often hear the whine through the speakers. It usually meant that capacitor inside the distributor was failing. The addition of a capacitor here is to provide a capacitive reactance to high
frequency spikes of AC put out by an auto's generator or alternator via the "A" lead on the schematic. Here you can find
the old wax paper one and replace it with a 0.47uF if you wanted to. Physically is must be outside the windings of the transformer and connected to one side of the inductor (be careful there) and shielded with the transformer to ground.
If you have put in an electronic ignition (like many old car guys do) you wouldn't need the capacitor inside but the one
you replaced with another value did the trick.
Thank you for that information. Oh yes I recall the whine. I added a Radio Shack choke to my power line in my '67 Chevy which seemed to have worked fine...thinking back 45 years there. Of course over the years I replaced the points and condenser many times. Yes this '53 Chevy does have electronic ignition and electronic voltage regulator too. It is planned to put a cap on the generator as well. So if this did not have the electronic ignition, we would need that paper cap replaced with another and put inside the transformer can? We could not take care of the generator and ignition whine before it gets into the radio? Thanks again.
@@PracticallyFixed Answer to question 1 is yes. Answer to question 2 is maybe, with the capacitor put back as a back up. You took the trouble to open the grounded box around the transformer to seal up any interference but I would have put a .47uF back inside to complete the LC filtering in this circuit. It was necessary back then when the car was built. Modern electronics like alternator to replace the generator and solid state ignition will mean it was no longer needed.
Greetings:
Paul Carlson of "Mr. Carlson's Lab" had a similar transformer with two embedded capacitors. He acquired a retired oven-toaster from a thrift store and cut a hole in the top to permit nesting the transformer on the cut-out with a substantial portion inside. it will be smelly. So outdoors is likely a good idea. I think his transformer had a boxy shape where he opened the top to both watch the tar melting and remove it when "cooked". You may need to remove any end-bells and position a capture pan beneath to catch the melted tar for reuse. You may need to improvise a support while heating. You need to monitor the melt to remove the heat before any exposed portion of the tar-free transformer is burned. The capacitor should be found and removed. An external safety cap can be sustituted, while the transformer is retarred. I know it's a mess. The retarding process needs to be planned for ahead of time including any connecting-wire replacements. When done, you will feel very accomplished and tired. The cap was part of the mfr of the unit; one less part to add later. The tar should have reduced its needed size due to its heat dissipation ability. Hopefully, you will find and correct the cause of the excessive current consumption before it happens again.
Hello James and thanks. Yes I saw Paul's video and hoped that I would not need to heat up the unit to extract the transformer. As you can see in the video, the dried up and leaky cap was right on top luckily, under a very thin coat of tar, and I was able to remove it without removing the transformer from the can. Thanks again.
Hey PF, not sure I follow the rational of removing that part of the circuit. Maybe I wasn't listening close enough, but not knowing exactly what this radio will be used for, I can't help but wonder if that was part of the suppression of the contact points and/or generator noises. I think I would have soldered an insulated wire to the end that went to the center tap and ran it out through a hole in the side of the case so that you could replace the cap if needed. Then again, maybe the spark gap caps you were talking about after the transformer work are enough to deal with that noise. If I had to guess, I would say they all work in conjunction with one another to filter or suppress that noise. Just my guess. :)
Hi Doug. Thanks for commenting, so I will clarify what I was doing there. The capacitor inside the transformer was no longer filtering much of any noise due to the high amount of leakage it had. I believe the previous restorer found the noise due to that cap to be a problem and as a result mounted that blue Xicon 1000uF electrolytic cap on the power line going into the transformer, next to that spark plate disk. In an earlier episode, I had removed that Xicon cap to see if it was needed and it was indeed, to control noise. What perplexed me was 'why was it there' since it was not on the schematic. When we found the disintegrating cap inside the transformer and measured how leaky it was, answered that question.
So instead of removing the old capacitor from the transformer (he may not have known it was there, or didn't want the hassle), he effectively mounted the Xicon capacitor in parallel to the leaky one. Meanwhile the waxy paper cap continued to deteriorate. The heat in the transformer, to which the leaky cap was beginning to contribute, caused the wax to melt and disappear causing the cap to fall apart when we touched it. It was a crispy critter by the time we got to it. So what we did here was remove the old capacitor from the transformer, and replaced it with a film cap of the correct value, in place of the Xicon.
Since the spark plate disk had such low capacitance compared to the .5uF cap we were moving, I do not think it was forming a Pi filter of much effectiveness anyway. So whether the .5uF cap was inside or outside the transformer would not make any difference. So as you pointed out, if it is there for filtering the generator or points, etc. if could be mounted either place. Therefore I mounted it outside. The transformer naturally gets hot so no need to subject the cap to that service environment, plus if it ever needs to be changed it is easily accessible.
(Spark plate cap: it is possible they are there to handle a voltage spike like a lightening suppressor on an outdoor antenna wire entering a house - the voltage would jump a gap and let the surge go to ground. Something which those early cars seem to have to deal with was static charge building up, apparently from the tires. The Chevy radio shop manual talks about adding static eliminators on the wheel hubs and also adding anti-static powder inside the tires. I read on a forum recently that the modern method of making tires makes that no longer such an issue.)
So I hope that explained that I actually did not remove a circuit intended to be there, but did (re)move a bad capacitor from inside the transformer to a good capacitor outside. It is still on the power line to the center tap, bypassing to ground. In the meantime I removed the paralleled blue Xicon which I viewed as being a band-aid. Thanks again!
@@PracticallyFixed No, I understand what you did, but my point was it is impossible to put the circuit back like it was without having access to the lead on the end of the internal cail that goes to the tap on the primary of the transformer? Maybe from a DC point of view it might not matter, but it seems to me that someone had a reason to wire it in as it was originally. :)
Hi Doug.
Why was there a coil of wire in the transformer can too? I do not know other than perhaps the engineers wanted a stocked design which could also work in other applications. I saw it also in other DELCO auto radios from that era. Also checked out a Philco which did not have it in the can that I could tell. There are other coils of wire (without cores) inside the radio chassis as you can see, one for the in-coming DC supply and the other going to the heaters. On the parts list the ones in the chassis we can see are termed "hash chokes". So there is already one of those on the DC supply to the transformer before the cap we added. As you say, it is a DC supply line, intended to be clean with little noise, and other than possibly forming part of a Pi filter, I could not think of why it would matter in a practical sense which side of the tarred coil the capacitor was mounted, and tested it accordingly.
So regarding if it mattered, it does not seem to after testing showed it eliminating the line noise. And there was a lot of time this radio ran afterwards without a problem. If there is a problem when put into the car, I will report back.
Thanks again.
(ps, after that earlier reply I gave you I did a little research on static from tires in the 40s-50s - get this: they talk about going back to some of the earlier methods of making tires so they Will generate static electricity and using it for providing battery charge for EVs. What's old is new again.)
Hopefully, the 53' Chevy owner has noise supprrssive ignition wires and an electronic ignition distributor to reduce noise.
He does have electronic ignition but will be adding a condenser to the generator per the installation instructions. Thanks
You have to know when to stop🎉