A TRANSFORMER'S DARK HIDDEN PROBLEM - 1953 VACUUM TUBE CAR RADIO Pt5 - CHEVY MODEL 986668 [4K]

Vacuum Tube Radio for a Classic Car Restoration series.
In this Part 5 we investigate the tar-filled transformer to see if a factory installed capacitor which was in the transformer can was either removed or replaced when a prior Re-Cap job was done. It "Looks Re-Capped".

This transformer may need to be de-potted from the tar to get to where we can see if we have a problem still there or not. How can we fix it?

In Part 4 we looked at putting in a modern, solid-state vibrator into this antique car vacuum tube radio. It will replace the period electro-mechanical design vibrator demonstrated in Part 1 to run quiet and also to provide a longer life for maintenance of the radio.

Also in Part 4 we check and adjust the Alignment of the radio so that is receives as well as it can.

In Part 3 we addressed a vintage Vacuum Tube Car Radio which receives well, but the tuning mechanism was very hard to move affecting the push button capability was well.

In Part 2 we went for First Full Power Up on this Vacuum Tube Car Radio and let's see if it works. We needed a variable DC power supply with enough power to drive all those tubes - now we have one that we had to find and fix, the EICO 1064.

In Part 1 we checked out this old tube car radio which has been worked on with upgraded capacitors in the recent past and test out its transformer and vibrator type power supply and see if we can develop B+.

This radio belongs to the owner of a beautifully restored 1953 Chevrolet Deluxe Two-Ten classic car he has owned for decades since a teen. He picked this vintage tube radio up not long ago but had not attempted to power it up. This will fit into his Classic Car Restoration.

See the checklist which appears when status changes, for tracking what is discovered that needs addressing in Red, followed by Green when resolved.

Playlist:

EICO Power Supply:

VINTAGE TEST EQUIPMENT USED ALONG THE WAY:
EICO 1064 Power Supply and Battery Eliminator ca1962
EICO 625 Vacuum Tube Tester
Fluke 27/FM Mil Spec Multimeters ca1986
Sencore SG-165

NOTE: This is not instruction, it is for entertainment for people like me who enjoy watching projects and the experiences gained. If you attempt to do any of the things in this video you are at your own risk. I am using special tech-bench safety equipment not detailed here so don't take for granted you can just plug these old items in safely without them being checked and repaired correctly. Check out the link below to Mr Carlson's Lab video below.

ACKNOWLEDGEMENTS AND REFERENCES:
[note: am in no way representing how these folks have shown doing these things - I don't even think they would approve.]

@xraytonyb

Thanks to shango066 for championing the approach of "fix it first", before mass re-capping. See shango066 for many examples of that approach.
@shango066

Awesome discussion of bench safety including variacs and isolation transformers by Mr Carlson's Lab (highly recommended):
@MrCarlsonsLab

Modification method for a commercial Tripp Lite isolation transformer for tech-bench use by Todd Harrison, his channel is called ToddFun:
@ToddFun

Camera: Canon G7X Mark III
Mic: Rode Micro
Video Editing Software: Power Director
Video Editor: just me

[jeffreyhickman]

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.

[kilcar]

Beautiful work. I love the attention to detail and the intuitive process. Your work would be an asset to NASA for certain!

[jimnewman]

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.

[bauhaus_PoetryinMotion]

I have no idea what you are doing or how it works, but it is fascinating to watch! Thanks for sharing! Liked and CONNECTED!

[janbill]

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.

[andrewwhite]

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.

[tigerelectronics]

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!

[hestheMaster]

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.

[jamesmdeluca]

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.

[DERB_Seymour_Indiana]

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. :)

[kilcar]

Hopefully, the 53' Chevy owner has noise supprrssive ignition wires and an electronic ignition distributor to reduce noise.