Hello,
In my tube tester project I'm trying to make the schematic jibe with the photos I took during tear down. In the process I did not note the polarity of the disc capacitors.
Can anyone help with the two photos?
Many thanks.
Ceramic capacitors are unpolarised.
Ceramic and film capacitors are not polarised, though you will find on a lot of film units a black band at one end. This is to indicate ther end that is connected to the outer side foil, and you normally connect this end to ground if you are using it for decoupling, as this reduces the RFI that the capacitor can emit from the outer surface ( only really important if you have it right next to a valve grid with a very high impedance, otherwise it makes no difference) in certain circumstances.
Electrolytics on the other hand generally are polarised, unless you get unpolarised ones.