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Ah, very interesting point of safety info. Thank you for the comment. I generally would not use the VTVM for such high voltages anyway, as the shield is connected directly to the case, but definitely good to know.

Ha! You are darned right it would! Better to just trim them off.

I use a DER DE-5000 LCR meter. They are not terribly expensive. Some of the little Chinese made "Transistor Testers" off eBay will measure capacitance fairly low as well, but I am not sure they are accurate (or read small enough capacitance) enough for this task. The value *might* be listed on a schematic or parts reference, or you might find something by web searching for the specific radio or part number on the can. You can also simply try some capacitors out and see if they work for the full range. More time consuming, but definitely gets the job done. I would start with 100pF or 150pF and go up or down depending on the results. You could also try to calculate the required capacitance based on the desired frequency, but for that you would need to know the inductance, which may or may not be listed or easy to measure either.

@@PelDaddy ok thanks. Yes the cheap Chinese ones bother me as you usually get what you pay for. I'm sure some trial and error may be necessary, but the radio when it doesn't exhibit the silver mica arc over is extremely sensitive and clean. But when I get the arc over holy cow the continuous static is enough to blow you out the room and it can last for a while before it clears. I will look into the meter you referenced as I don't mind spending money on good quality meters. I want to try to get as close as I can to what's in there. I have also heard of the pencil eraser or razor blade method, but figured what you are doing is probably best long term as im sure the problem will eventually come back and then i have to disassemble again.

@@kwacz The little Chinese Transistor Testers are actually pretty amazing, and good for a lot of things. But they can only read capacitance down to a certain level, and I think that may have been around 100-500pF, if even that low. There is usually no ignoring the silver mica disease; indeed it sounds like thunder! There are definitely a number of methods to fix the silver mica issue. Like you said, I wanted one that I knew would last a long time. I also like the idea of being able to easily replace the capacitors now because they are on the underside of the cans.

Thanks for the comment. I have not tried that. I still think I prefer putting caps below the can because that way they can be changed easily in the future. Also then you don't have to worry about the dielectric breakdown of whatever material you put in there at the voltages involved (since most washers and paper don't come with datasheets specifying breakdown voltages). But I am sure it could work, and I am guessing you have used this method with good results. Thanks again.

Thanks for the comment. I think it's actually worse than when I made this...

@@PelDaddy oh no doubt, I also just noticed this was made before Rythm N'Hue went under too, how depressing.

Thanks for the comment. I'm sorry you had trouble understanding the audio. My voice is not the most piercing...

@@PelDaddy Replacing the 20mfd with a 47mfd capacitor did not affect the performance of the vtvm? Good video very interesting and informative. Thank you

@@PelDaddy I have this model vtvm but the circuit board cracked in three places can super glue work on the board material? and is the material bakelite? Is either super glue or JB weld that i am thinking of using. Thank you

@@SDsailor7 Sorry for the late reply. The capacitor just smooths the power supply. Won't affect the accuracy.

@@SDsailor7 I think it is phenolic board, but I am not positive. Personally, I would try epoxy (JB Weld)

Thanks for the comment!

I'm glad it helped. I hope your restoration goes well. A VTVM is a very underrated tool.

LOL. I call it the Teletubbie Edition of the Simpson due to the bright colors. Still a great meter, even with the slightly different ranges.

Thanks for the reply. I did consider using card stock between the contacts. It will work well, until it eventually disintegrates into dust (in a decade or four) and the contacts short out. This was why I decided to clip the contacts. No chance of ever shorting again. There are certainly many ways to do this. This was my first encounter with the issue. have since improved my techniques quite a bit, but the processes is basically the same. Note that even paper is a dielectric, and there will still be some capacitance between the plates if you put cardstock in between them. Of course it likely won't matter as it should be very minimal and you should be able to tune it out.

...I wouldn't use CARDBOARD- I'd use plastic shim stock...

Very very few vtvm’s measuered current, usually the operator of the vtvm would measure the voltage drop across the components in the circuit under test to calculate the current using ohms law.

Thank you for the comment. I am glad you found the video helpful. This is a scope that was way ahead of its time, and still has the most beautiful, thin trace to look at. Hopefully you can post a video about your Phillips scope. I'd love to see that one in action!

I did a total restoration on our little comet a few years back.....basic woodworking, you should be able to do it yourself. If not, I am in Michigan

Thanks for the comment. To determine the cap size either look at the schematic, or do the alignment first and then measure the capacitance with an ESR meter after you remove the can, but before removing the old mica. If that fails the just try some standard values that you find in similar radio schematics and see if you can get the circuit tuned. Adjust the fixed values until you are able to get it within range. I would also suggest posting about whatever radio you are working on to the Antique Radio Forum. The guys on there have all sorts of knowledge of all kinds of radios.

Thanks for the post. I had some discussions about this at the time with the very knowledgeable folks on the Antique Radios forum. Most seemed to think that cutting the contacts off was the safest bet. If you insulated them you would definitely want to use something like a thicker piece of plastic. Cardboard or other materials would break down. You wouldn't want these things shorting together in a few years. Good luck!

I do read all the comments. Thanks. I will help if I can. Otherwise, I would highly suggest the Antique Radio Forum ( antiqueradios.com/forums/index.php )

If it works it works! I plan on attaching some heat sinks to the underside of mine to extend life span & possibly lower amp load. We get High Ambient Temp rated motors out here in the desert, but they can still go out on thermal overload..... Condensers don't do well under direct sunlight and intense heat

Thanks for the comment. In this particular transformer if you do not cut the tabs (plates) they will touch each other short out. The mica was the dielectric in between the tabs. Once it is removed, the plates can touch. Some people put an insulating material in there instead, but of course you are they making a capacitor, possibly of the wrong value (but maybe perfect). Whatever you do don't use some insulating material that will deteriorate, like cardboard.

Thanks for the reply. I like Deoxit 5 and the unter cleaner as well. One thing to note about any cleaner with a lubricant (including Deoxit 5) is that in can contaminate phenolic wafer switches and cause arc overs on high voltage switches. I like to clean first with MG Chemicals Electrosolve. Then you can lubricate with Deoxit 5 or CRC-26, or Fader lube, or the RS tuner cleaner.

@@PelDaddy the auto store sells a contact cleaner I think the brand is crc contact cleaner do you no anything about that one ,and thanks for the info on the other cleaners,very usefull

Yes, those are the model numbers of the meters. Thanks for the comment.