Capacitor replacement confusion

[dscottguitars]

Hi, this is my first time trying to repair/tuneup an old Stromberg Carlson HiFi. Model 1121 console, with AM, FM, Shortwave and record player. Schematic link: http://audiophool.com/Schem_R/Stromberg_1121-schem.gif

Do the caps in the picture need replacing? They look like a type that sells on ebay for quite a bit, similar to the bumblebees and black beauties. I've seen some websites that say 'replace all those bumblesbees' and some that say they are okay to use. So this is why I'm confused. I know that electrolytic caps should be replaced, like the ones in the cans, but this type that are sealed seem to depend on different opinions.

There are many in the radio that are used as bypass caps, and/or tone and filter caps.

Any advice would be really appreciated...

Also, what is that acrylic-plastic device in the bottom of the picture?? There are a few of them with interleaved windings and components on them.

Thanks,

Daniel

[Zero Cool]

All of those old caps should be tested to see if they are at least close to there rated capacitance. replace any that are way off. 10-20% or more off. throw them away if they are. guitar guys won't want them if they're shot!

[Kay Pirinha]

Originally Posted by dscottguitars

Also, what is that acrylic-plastic device in the bottom of the picture?? There are a few of them with interleaved windings and components on them.

Hi Daniel,

this ain't no acrylics, but polystyrene, which is good for bobbins in radio frequency applications.

Best regards!

[DeathRex]

Those capacitors are paper covered in wax. They tend to be leaky. If you want it to sound better than new, you can put in Solen or $1 or 2 capacitors. In the RF section you can just use the cheap $0.50 yellow film capacitors. Don't need to use new or old "bumblebees".

[astouffer]

Replace ALL the wax capacitors. If they aren't bad by now they will be soon enough. Its cheap insurance.

[dscottguitars]

what about using sprague orange drops caps? I can get 20-0.01/600v for about $12 on ebay.

Either that or PIO caps too...

[Frank Berry]

Orange drops should be fine for this application. Good price too.

[astouffer]

Agreed, orange drops are pretty good.

[dscottguitars]

I have another question about two of the caps. I cannot get to them without really tearing apart the chassis and stuff. They are the two in the center of the picture, light blue color, marked 'Solar' and 'sealed tite' on them. I am pretty sure they are the number 1 and 2 tubes shown on the schematic- http://audiophool.com/Schem_R/Stromberg_1121-schem.gif - labeled Radio Frequency Amplifier and Converter Oscillator. I am hoping they will be okay...