HISTORY:
Sustainability is the name of the game! Anything (that has been tested and still functioning properly) should be repurposed creating saving in wasted Ee and reducing the poisoning our environment when items are buried in the earth at the local tip needlessly.
Never heard of Ee? It is a concept that creates a measurement of ALL things (not just electronics) that humans have made and the energy used in obtaining the raw material, processing the materials right through to a finished product and even should include the shipping of the item to the distributors/retailers.
If you would like to know more about Ee values, please take a look HERE
This electronic component is USED, old (very old!) workshop stock and it has been tested as functional.
How long since you've seen some Germanium diodes from the OA series in the original black casing? These were in common use way back when I was a teenager in the late 1960's, I cut my teeth on devices such as this - this was the beginnings of the "new fandangled" semiconductor technology around the mid 1960's
Up until this time in the 1960's valves were the thing then along came these little black beasties!
I do not know who manufactured this particular diode, yes its the good old black coated glass with the RED dot but if the manufacturer was marked on the device, it has now long since rubbed off! Luckily, the type number is still clearly visible.
After all these years, I still have this semiconductor - not much call for an old Germanium diodes these days so I expect the new owner will only want these for 'museum' purposes - at least that's better than it being buried in the ground!
UNIDENTIFIED - Germanium Diode
Possibly Made in England
Circa late 1960's ~ 1970's (60+ years old!)
Type: OA5
Batch code: 2HH
Germanium semiconductor
Leads are tin plated
Purpose: small signal rectifier - often used as a 'detector' in crystal sets back in the day
Even after all these years, datasheets are readily available online but I have also extracted some important information from the datasheet and included this in one of the photographs.
WARNING!
If ever the new owner was considering using this device, NEVER bend the leads less than 1.5mm from the body. The packaging is quite delicate and if you make a bend too close to the body, the lead is likely to snap off!
COSMETIC CONDITION:
Very good condition
Black body is undamaged and the coding printed on the casing is easily readable
Lead lengths remain very useable, one leg is 28mm and the other is 17mm length
Leads are still quite shiny, no heavy oxidisation
TESTING:
Made a quick "Go No-Go" test with the Transistor/Diode tester and it is reading fine - no issues
This diode has now been placed into a sealed plastic packet, ready for a new workshop!
