How to read one
Three bands, three jobs. The first is the first digit, the second is the second digit, and the third says how many zeros to put after them.
The colours count from zero: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. So brown, black, red is 1, 0, then two zeros: a thousand ohms.
Click a band to change it, or take a mystery one and read it before you look.
Why a code with no secret?
Nobody is hiding the value. The part is a few millimetres long, it gets soldered in at any angle, and it is fitted by people who may not read the language it was made in. A number would be too small to print, would face the wrong way, and would rub off. Bands of colour are readable upside down, in a dim room, through dust, for fifty years.
That is the second reason codes exist. Not to hide, but to shrink: a barcode, an airport code, hexadecimal, a chess move. The information is too long and the surface too small.
And it still shuts people out. If you cannot read the code you cannot fix the radio, which is exactly what a cipher does on purpose and this does by accident.
Back to signals The ciphers