.05 MFD 600 Wvdc capacitor in Rek O Kut L-34

[marcushifi]

I am trying to figure out what capacitor I need to replace this one on my Rek O Kut JR L-34 turntable. It is for the switch between 33 and 45 rpm.

This may not be the right forum but any help would be appreciated.

 

[century tek]

Well, you need a .05 MFD @ 600 Volt capacitor. What else do you need to know?

Do you get any loud pops through the speakers when switching between 33 & 45? This capacitor would normally be across the power switch to prevent pops but why on the 33 / 45 switch?

This capacitor normally quells pops and RF interference from happening so if you are not getting any of that, I probably wouldn't bother with it.

 

[Retrovert]

That may be a motor run capacitor, not an RFI suppressor. It's on the RPM switch because it assists with an additional winding to kick up the speed.

If so, a PP film capacitor is best.

 

[marcushifi]

That may be a motor run capacitor, not an RFI suppressor. It's on the RPM switch because it assists with an additional winding to kick up the speed.

If so, a PP film capacitor is best.

I think it is a motor run capacitor. The motor isn’t getting up to speed like it did a year ago. I’ve lubricated the motor through it’s lubrication holes and nothing has helped so I’ve been wanting to find a replacement capacitor.

 

[Retrovert]

I think it is a motor run capacitor. The motor isn’t getting up to speed like it did a year ago. I’ve lubricated the motor through it’s lubrication holes and nothing has helped so I’ve been wanting to find a replacement capacitor.

Any ordinary PP (polypropylene) film motor-run capacitor will do. Just make sure the voltage rating is high enough.

A "motor start" isn't rated for continuous duty.

 

[gadget73]

if that is directly across the switch contacts, I'd wager it is indeed an RFI supressor. Normally motor run caps will be tied from line to a third lead direct out of the motor. They are also rated in volts AC, not DC like this one is. This looks like an old "ceracap", which are usually some flavor of film cap stuffed into a ceramic tube.

of course I suppose its not impossible that some mfg cheaped out and used a general duty cap for the wrong task. I suppose if it lasted 40 years it can't be that wrong. I might be tempted to just toss in an equivalent modern part and leave it be for a few more decades.

 

[avionic]

https://www.newark.com/nte-electronics/mlr503k630/capacitor-polyester-film-0-05uf/dp/33C5196?
https://www.digikey.com/product-det...ctronics-cde/715P47356LA3/338-4365-ND/6142316

 

[Retrovert]

if that is directly across the switch contacts, I'd wager it is indeed an RFI supressor. Normally motor run caps will be tied from line to a third lead direct out of the motor.

Right. We'd need to see the motor wiring to be sure.

of course I suppose its not impossible that some mfg cheaped out and used a general duty cap for the wrong task. I suppose if it lasted 40 years it can't be that wrong. I might be tempted to just toss in an equivalent modern part and leave it be for a few more decades.

As you know, the common practice among cheap manufacturers was to grab whatever inexpensive non-polar DC capacitor was in stock and derate for for AC as per: 1 / √2 x DC rating ≈ 71% x DC rating.

This looks like an old "ceracap", which are usually some flavor of film cap stuffed into a ceramic tube.

I remember those capacitors being used in AM car radios for ignition-coil noise filtering.

Modern PP film capacitors are certainly a robust and inexpensive replacement. The question is working voltage and durability in the presence of spikes and noise.