paper wax caps

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paper wax caps

Post by Sinatra1982 on Fri Nov 11, 2016 10:37 pm

I have recapped my third radio and have the same problem with all three of them. Each one pulls in stations, but with a lot of distortions and static. I just got done watching a you tube video on how to replace them.
A lot of the small paper wax caps have a black ring on one end, however the new ones I put in, such as the yellow poly and orange drop do no show a negative end. I thought it didn't matter on these kinds, but the video says it does matter. But if this is true, how do I tell which is negative? And could this be causing the same problem on all three radios? Thanks.

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Re: paper wax caps

Post by Wildcat445 on Sat Nov 12, 2016 1:05 am

Paper coupling caps technically have polarity. The black band indicates the negative end. The yellow replacement caps you buy do not have the black band. Polarity on those is unimportant. How you connect caps likely will not cause the static you mention. If you have static in all three radios, operated in the same environment, a suggestion I would make would be to suspect something external to the radio causing the interference. What could it be? Almost anything electrical in your home or wherever the radio is located and in use. I would also caution you about watching videos on YouTube about radio repair unless the person making the video and offering the advice is one of known good reputation. There are plenty of hacks on YouTube. The information you cite is simply wrong. Electrolytic caps, typically used in power supplies have polarity that must be observed. Good luck.

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Re: paper wax caps

Post by Sinatra1982 on Sat Nov 12, 2016 3:57 am

Thank you very much for that information and advice. I am going to move radios to different location in the house. I am presently working with them in the basement.

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Re: paper wax caps

Post by Wildcat445 on Sat Nov 12, 2016 7:21 pm

Safety first if you are running hot chassis radios in a concrete basement. You should always use an isolation transformer to help guard against electrical shock when working with hot chassis radios. An isolation transformer isolates one side of the line, so your body is not available as a path for electricity to ground. This protection is vital when you are working on a concrete floor.

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Re: paper wax caps

Post by Sinatra1982 on Sun Nov 13, 2016 1:41 am

Finally got this radio picking up better after playing it upstairs. However it has one problem, from the middle of the dial to the right end it tunes and plays fairly well. But when tuning from left to middle of dial all I get is very loud static. I am thinking maybe the tuning capacitor fins might be touching, but they look ok.

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Re: paper wax caps

Post by Sinatra1982 on Sun Nov 13, 2016 1:48 am

I am sorry I didn't state the problem correctly. When I tune from left end to middle I get nothing, no sound. When I start to reach the middle of the dial it gets very static. And the when I tune from middle to the right end of the dial I lose the static and can pick up stations all the way to end of he dial. Thanks.

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Re: paper wax caps

Post by Wildcat445 on Sun Nov 13, 2016 3:50 pm

Using a good light and magnifying glass, see if you can find any junk lodged between the fins of the tuning capacitor. If you have an air compressor handy, you might give it a controlled blast of air to dislodge any junk that might be there. Then test for any improvement in performance. It is possible the fins are bent and touching, but that condition is a bit more rare. Sometimes it does not take much junk lodged in the tuner to mess things up pretty good. Good luck

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Re: paper wax caps

Post by 75X11 on Sun Nov 13, 2016 11:54 pm

Have you used a good contact cleaner to clean out where the shafts for the moveable fins of the tuning capacitor pass through it's frame?  There can be corrosion and lubricant debris there that can impair it's operation.  Some of the noise you are getting can be caused by the power supplies for the electronic devices you have in your home.
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Re: paper wax caps

Post by Sinatra1982 on Mon Nov 14, 2016 4:34 am

I have done everything everyone has mentioned, but still same problem. I am new at this and so this will probably be a dumb question, but.. I know there is a first and second IF transformer. Does one work the first half of the dial and the second one work the last half of the dial? I get just a little hum on first half and pick up some stations and some static on second half of dial. Dials are clean and not rubbing anywhere I can see, turns freely.

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Re: paper wax caps

Post by 75X11 on Mon Nov 14, 2016 9:38 am

Your 1st and second IF transformers work with the full coverage of your radio.  What you describe sounds more and more like noise generated by power supplies in your home.  If you have cable TV, it's power supply can cause noise over a portion of your dial.  A computer power supply can also.  a cell phone charger can, and some lights can also.  One good way to tell is to unplug your electronic devices one at a time while your radio is on and when they are all unplugged, not just turned off, see if your noise decreases.
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Re: paper wax caps

Post by Sinatra1982 on Tue Nov 15, 2016 12:58 am

I took radio outside where there is nothing electrical, still same problem. I hadn't checked the tubes yet because the glass ones lit up good and the metal tubes felt hot. I got to thinking maybe a tube could seem good but still be bad too, so I checked them in my tube checker. The 12SQ7GT showed in the replace category and 12SK7GT showed only around 62%. All other tubes showed good. Three of the tubes state on the schematic state that they are glass, but are actually metal. And the 50A5 on the schematic is actually a 50L6GT.
Could any of these things cause distortion and not being able to pick up stations very well? The radio is a Rauland Corp. model 546T.
I'm sorry for asking so many questions at once, but I am catching on very fast.

I have another radio doing the same thing and checked the tubes and most are only the 60 to 65% range. So maybe bad tubes are causing most of my problems. Thanks..

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Re: paper wax caps

Post by Wildcat445 on Tue Nov 15, 2016 11:51 pm


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Re: paper wax caps

Post by Sinatra1982 on Wed Nov 16, 2016 12:28 am

Thank you, very good information and advice.

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Re: paper wax caps

Post by Sinatra1982 on Sun Dec 11, 2016 10:55 pm

I am sorry to bring this up again, however I am working on a Silvertone 4585 console and there are a couple of paper wax caps that have imprinted on the a arrow that says to ground lead. It doesn't matter which way you connect the new ones, is that correct?
And also in the radio there is a .0033 cap that says 1600 VDC. I haven't come across one before with that much voltage. Is this a hard to get cap? Thanks again.

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Re: paper wax caps

Post by Tony V on Mon Dec 12, 2016 1:35 am

When replacing paper capacitors with the new capacitors, they are not polarity sensitive so yes it doesn't matter. Electrolytic's on the other hand ARE polarity sensitive and must be hooked the same as the original's or they will explode, damage the radio or worse may catch fire. The cap you mentioned isn't hard to get and that voltage isn't that uncommon. Most capacitor suppliers have that value or close enough to it. http://www.justradios.com/capacitors.html is a good resource for capacitors and is who i been using for years with good results. Good luck on your restoration.
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Re: paper wax caps

Post by Sinatra1982 on Mon Dec 12, 2016 2:55 am

Thank you very much for that. I wanted to make sure before I installed them. I have one more question I failed to ask. The caps that are in a small bakelite box filled with black goo, can those be unsoldered and new ones connected on the outside of them?

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