Electronics Weekly
Now that I am properly worried about capacitor failure, I have taken photos of two of the capacitors on the same board (plus the lovely new electrolytic replacement already installed – bottom left in the photo).
Both of the 1985 vintage capacitors are made by Philips.
The yellow one is an X-capacitor across the primary of the on-board transformer. The top says MKT-P and 330 (photo left) and, if I found the correct data sheet, it is described as: ‘a low-inductive wound cell of metallised polyester film and blank paper, potted in a flame-retardant case.’
‘Polyester’ had me relaxing, and ‘paper’ had me reaching for the side cutters – does any one know if this type needs replacing?
The second one (right, excuse the poor focus) says 100 MKT and I cannot find a Philips data sheet. Similar-looking MKT parts (but not ‘100 MKT’) are polyester. is this a keeper, or not?
There are actually three of the orange ones on the board, all in low-voltage positions (SCR gate-to-cathode) and noise reduction.
Thanks in advance for any wisdom shared.
The orange capacitor is a Philips 368 or similar, 0.22uF 100V polyester. Nice and reliable unless you pull the leads apart and crack the case.
At least the X2 isn’t one of the dreaded RIFAs. The problem with those isn’t the paper dielectric but the fact that the resin cases crack letting in moisture. People have found unused New Old Stock ones full of cracks.
As for the orange caps, read up on Nakamichi Orange Cap Disease. You might want to change those.
Aha! You named them. 🙂
I had a bag full of NOS, all of which met the bonfire.
The vintage radio sites are full of comments on antique capacitors.
Even the very occasional silver mica.
Neither of those are the paper dielectric epoxy coated capacitors of evil reputation.