RCA 195A overhaul

[k7mdo]

 A quick question for the group.  Probably know the answer but thought I would run it by the experts.

I acquired an RCA 195A meter and want to just re-do it for experience.

Inside I found it untouched and there are three electrolytic caps marked .25 mfd at 400 VDC. 

I am certain they need replacement from their gooped out looks but I don't have electrolytics for use but do have .25 mfd 630 vdc "orange drops" available.  Is there any problem with using them as opposed to the "electrolytics"?

Tom

[Pete, WA2CWA]

195-A manuals say C1, C4, and C5 should be .25 mfd at 300 volts. There is no mention of them being electrolytic nor is there any polarization marking on any of the schematics including an original factory engineering drawing.

Model 195-A, Code 149-A, says C1 should be 1 mfd. The "Code" were for various product releases of the 195-A.

[k7mdo]

By twisting them aroud a bit I see they are a mix of 300 vdc and a 400 vdc but all three are .25 in this unit. 

The unit looks "terrible" on the outside but inside it is passable except for the old age mildew stink...  use the orange drops?

Tom

[Pete, WA2CWA]

I don't see any reason not too. I would also check all the resistors, tubes, etc. The drawing date is 1945 for the thing so it's probably at least 65 years old. Most resistors have a 5% tolerance; some have 1% tolerance.

[k7mdo]

Wow, that is older than I thought.  Yes, the resistors look ancient .....  I will have to replace the caps and then put on a new line cord before I warm it up with the variac. 

I doubt there is much to do about the mildew odor but heating it up and keeping it in the radio room rather than the outdoor dumpster where I found it might help.

Will report progress if you are interested, thanks, Tom