OA 91, Tube OA91; Röhre OA 91 ID34052, Solid-State-Diode
OA91 Fiches technique(PDF) - List of Unclassifed Manufacturers
OA91 ; Diode Germanium Ge Signal Rectifier 90V 50mA, DO-7 (2 pcs) - Al-Hekma Electronics
Peak Electronic Design Ltd 💙🇪🇺 on Twitter: "@KangaSales The OA91 is actually my favourite germanium diode (built my very first crystal set with one). I must have one somewhere here at Peaky
Detector Diodes ~ crystalreceiver.co.uk
10pcs OA91A Germanium Diode, Point Contact Type, OA91, 0A91 560 : Amazon.ca: Musical Instruments, Stage & Studio