Point contact diode's colour rings - UK Vintage Radio Repair and Restoration Discussion Forum
MULLARD OA81 DIODE for Crystal Set Radio, Tested Germanium Point Contact 0A81 - £1.96 | PicClick UK
OA70 - Vint'Elec - Tubes électroniques vintage
i took a closer look at the germanium diode : electronics
Germanium Diode Gallery
Germanium Diode Oa 70 | vintage gold bonded germanium diode oa9 for stompbox or radio detector 1 99 picclick, oa 79 germanium contact point high frequency diode early flickr, 2x tungsram oa1180