[martin.m]

I had to repair a fault with the Magic Eye circuitry in a tape recorder. The problem turned out to be the little metal diode that feeds a negative voltage to the grid of the EM84 indicator. I fitted a germanium OA81 diode and this worked but the edges of the bar display were rather fuzzy. I found an original metal type on a scrap chassis and using this restored normal operation. What strange electrical properties do these diodes have and is there a modern component that can take their place?