The great capacitor debate.
Vintage ceramic capicator markings.
A collection of pottery marks using photos and images from our antique collection for easy reference and as a quick guide to the possible attribution of your latest porcelain collectible or pottery marks.
Old capacitor checkers are available cheaply at swap meets and on ebay.
I tend to take a middle line on this subject.
There are several tolerance marking systems used.
Two of the most common are shown here.
To test old capacitors for leakiness you need a capacitor checker that applies the correct operating voltage often over 100 volts.
Nos vintage rubycon 20 20 20 20 uf 450v quad can capacitor tube amp cap working 29 99 2 nos vintage 1965 crl 05 uf 16v ceramic disk guitar tone capacitors qty ava.
Ceramic capacitors are generally smaller than types like electrolytic capacitors and therefore the markings need to be more concise.
Capacitor tolerance markings in addition to the capacitance value and possibly the working voltage or breakdown voltage the capacitor may be marked by its tolerance.
The third digit is the multiplier which is 1000.
The first is used with small ceramic capacitors and appears as a single letter.
Ceramic capacitors which are usually tiny pancakes with two pins typically list the tolerance value as one letter immediately after the three digit capacitance value.
Sometimes figures such as 10n will be seen and this indicates a 10nf capacitor.
A variety of schemes may be used.
Markings of ceramic capacitor.
The markings on a ceramic capacitor are more concise in nature since it is smaller in size as compared to electrolytic capacitors.
There is an ongoing debate in the vintage radio press as to whether one should just replace the faulty capacitors or the whole lot.
I replace any that are faulty and any that look suspect.
Everyone seems to have a different opinion on this.
Thus for such concise markings many different types of schemes or solutions are adopted.
Often the value may be given in picofarads.
The value of the capacitor is indicated in picofarads.
Like all vintage equipment they will need routine service including capacitor replacement before they are reliable and accurate.
The first two significant digits represent the first two digits of the actual value which is 47.
The marks listed below are grouped as far as was possible in a logical order with similar signs graphics shapes etc grouped together.