I was a Navy Electronics Technician for 23 years, but it has been 25 years since I sat at a bench and I feel rusty.
I want to replace the capacitors in a turntable power supply that I am restoring. I am having a hard time finding exact or suitable replacements. In fact I don’t even remember what these capacitors are made of or what they are called. The turntable was manufacured in 1970.
I looked at Mouser and Digikey but did not get anywhere with respect to the voltage or axial type caps. Maybe a different type of capacitor? Film?
I have included pictures of the capacitors I pulled and a schematic. The schematic is from a manual of a previous model in this series and the values are different. I did annotate the values of the ones I need on the schematic. I did verify that the schematic is the same as the circuit I have on mine.
Maybe they don't need replacement. I just figured because of the age of the capacitors it would be wise.
(1) 0.9uF 200WV. AC
(2) 0.047uF 1000WV
Capacitor (2)'s working voltage seems high. And why such a difference in values between what I pulled and what was used on earlier models?
Any help on suitable replacements would be appreciated.
I want to replace the capacitors in a turntable power supply that I am restoring. I am having a hard time finding exact or suitable replacements. In fact I don’t even remember what these capacitors are made of or what they are called. The turntable was manufacured in 1970.
I looked at Mouser and Digikey but did not get anywhere with respect to the voltage or axial type caps. Maybe a different type of capacitor? Film?
I have included pictures of the capacitors I pulled and a schematic. The schematic is from a manual of a previous model in this series and the values are different. I did annotate the values of the ones I need on the schematic. I did verify that the schematic is the same as the circuit I have on mine.
Maybe they don't need replacement. I just figured because of the age of the capacitors it would be wise.
(1) 0.9uF 200WV. AC
(2) 0.047uF 1000WV
Capacitor (2)'s working voltage seems high. And why such a difference in values between what I pulled and what was used on earlier models?
Any help on suitable replacements would be appreciated.
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They look like Paper in oil caps , they aren"t made much anymore , you might be able to get NOS caps but are probably not to be found on digikey or mouser .......
Are you looking to replace them with the exact same caps or are you open to trying newer caps ??
The 0.9uF cap would be hard to find , but at 1uF and 200v would be easy to find in a Metal film , polypropaline ect cap ......
0.047uF could be found in anything from a Poly , metal film , ceramic ect , might be a bit more expensive in a 1kv variety but if you know the voltage of where it will be used then you might be able to use a lower voltage ......
Cheers
Are you looking to replace them with the exact same caps or are you open to trying newer caps ??
The 0.9uF cap would be hard to find , but at 1uF and 200v would be easy to find in a Metal film , polypropaline ect cap ......
0.047uF could be found in anything from a Poly , metal film , ceramic ect , might be a bit more expensive in a 1kv variety but if you know the voltage of where it will be used then you might be able to use a lower voltage ......
Cheers
I think you might have the positions of the caps mixed up, the one you have labeled .047uf should be on the power switch for arc suppression, thats why it's rated at high voltage. Value here isn't critical, but needs to be high voltage, mylar or disc cap should be OK. The other one, the .9uf is a motor start cap. I think mylar cap from .82uf to 1uf at 200v or more would be OK.
Mike
Mike
Your 1000 v turn off pop cap has been replaced in function by x2 caps with a UL/CE/VDE rating for 240 VAC service (or 120 vac). 1000 v caps for radio were pretty common in 1970 but are strange and wierd now, and safety rating agencies have gotten into the act. I salvage my x2 turn off pop caps from PCAT power supplies, the supplies blow up about once a year and it is not this part that blows up. They are across the power switch and have ratings logos all over them.
Ceramic disc caps and plastic film caps have taken over for capacitances less than 10 microfarad (uf now instead of mf). Bipolar electrolytic caps are extremely rare. Film caps are much smaller than they used to be. 1 uf should be fine for motor run, just don't buy a +80-20% one. I would tend to buy 400V or 600v instead of 200 v, you get some hash on the line from refrigerator and A/C turn off, lightning etc. In fact, the 150 V mos surge surpressor (blue disc) from a PC power supply would also be a useful thing to put across the AC line (western hemisphere). The rating on them is in AC rms volts, not DC peak like the capacitors. Put the surge suppressor across the AC input to the transformer for the electronics if any, it won't help the motor any.
Ceramic disc caps and plastic film caps have taken over for capacitances less than 10 microfarad (uf now instead of mf). Bipolar electrolytic caps are extremely rare. Film caps are much smaller than they used to be. 1 uf should be fine for motor run, just don't buy a +80-20% one. I would tend to buy 400V or 600v instead of 200 v, you get some hash on the line from refrigerator and A/C turn off, lightning etc. In fact, the 150 V mos surge surpressor (blue disc) from a PC power supply would also be a useful thing to put across the AC line (western hemisphere). The rating on them is in AC rms volts, not DC peak like the capacitors. Put the surge suppressor across the AC input to the transformer for the electronics if any, it won't help the motor any.
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Thanks everyone for all your advise. I looked in our local yellow pages and found a local electronic supply business. I always like doing business with locals when I can. Anyway, he fixed me up with suitable replacements
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