Diode? Identification

[rosinante]

The RN. That's where I learnt my memnonic , it ain't pc now, days of Alf Garnett and Chalky are gone , as is the absence of malice, now everything is construed as a misdemeanor or worse.
Chris

 

[puffernutter]

Buy Better Resistors Or Your Grid Bias May Go West (now that really dates me!)

and another one that is certainly not for public consumption ;-)