Old capacitor checkers are available cheaply at swap meets and on ebay.
Vintage ceramic capicator markings.
A variety of schemes may be used.
The third digit is the multiplier which is 1000.
Like all vintage equipment they will need routine service including capacitor replacement before they are reliable and accurate.
Ceramic disc capacitor code label will normally consist of three numbers followed by a letter.
The first two significant digits represent the first two digits of the actual value which is 47.
Markings of ceramic capacitor.
The value of the capacitor is indicated in picofarads.
Often the value may be given in picofarads.
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.
They are very easy to decode to find the value.
The marks listed below are grouped as far as was possible in a logical order with similar signs graphics shapes etc grouped together.
I replace any that are faulty and any that look suspect.
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.
I tend to take a middle line on this subject.
Two of the most common are shown here.
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.
Everyone seems to have a different opinion on this.
There is an ongoing debate in the vintage radio press as to whether one should just replace the faulty capacitors or the whole lot.
The markings on a ceramic capacitor are more concise in nature since it is smaller in size as compared to electrolytic capacitors.
Sometimes figures such as 10n will be seen and this indicates a 10nf capacitor.
Thus for such concise markings many different types of schemes or solutions are adopted.
This letter represents the tolerance of the capacitor meaning how close the actual value of the capacitor can be expected to be to the indicated value of the capacitor.
The first is used with small ceramic capacitors and appears as a single letter.
There are several tolerance marking systems used.
Ceramic capacitors are generally smaller than types like electrolytic capacitors and therefore the markings need to be more concise.