HISTORY (The Story!):
I remember the day .... way back when I was a youngster, electronics was my passion. Remember the independent electronic stores back in the 1960's ~ 1970's? - with rows and rows of valves in wooden drawers on the wall behind the long front counter and subsequently these were replaced by rows and rows of drawers with transistors.
Modern computers didn't exist, I recall a front window display at Radio Despatch showing this fantastic "computer" using LED numerical displays and the user "talked" to the equipment in HEX code!
I have fond memories of stores such as Radio Despatch down in Ultimo, Sydney and back in NZ there was a "special shop" called Elequip (Christchurch) which dealt in ex Military surplus equipment, LOTS of it - my days of salvaging components began then. I would ride my bicycle past his shop after school everyday, wishing I had more money! He would give me some chassis to play around with and lots of "dead" valves to break open to see how they were made and smell that gas! What I would give to have some of that old ex Mil equipment now!
Well, those days are gone - long gone but I still have remanents of those "golden days" of electronics and amazingly I discovered some folks STILL use these Ge transistors!
Germanium transistors seem to be a bit like the vinyl records vs CD war - nobody thought that anyone would use Germanium once Silicon became the "norm" but there is quite a strong demand for these old transistors I am told.
I am sorting through yet more of my old ~ very old bits and pieces, some new and some used.
These Germanium transistors are NEW (1970's NEW) and unused PLUS they are just a bit 'special' because the legs are Gold plated ... you often see terribly oxidised tin plated legs on these transistors being offered but the Gold plated variety are few and far between (much easier to solder!)
I found just one complimentary pair, the AC188/187, but I am going to 'split them' as I have been advised some folk just want the PNP or the NPN trannie, not both OR it may be desirable to have the gain characteristics more closely matched with another Germanium device. Both the AC188 & AC187 are available but in seperate advertisements ... look HERE
Now for the details ...
GERMANIUM TRANSISTOR
Type: AC188
Manufacturer is unknown .... no logo, no name on the body - see details below regarding exactly what is printed on the body
PNP
Intended function: Audio power, complimentary with the AC187
Package: TO-1 (Chrome like body not dull Grey)
TO-1 is a long cylindrical package, 11.66mm x 5mm diameter
No heatsink fitted (that's the K version) so you will need a heatsink that can support a 5mm diameter transistor.
There is no 'dot' or tab to indicate a particular lead, the three leads exit in a straight row but one lead is more distant from the other two - that is your Collector.
Special feature: Gold plated legs, 42mm length
BODY MARKINGS (Black printed onto the Chrome like body)
Orientation of the print is horizontal (this in itself is quite unusual as most often the markings are printed vertically with these TO-1 packages)
AC188
384
I assume the 384 is either a batch code or special manufacturer coding ... I actually think these transistors were intended for some 'hi spec' equipment from long ago.
TESTING:
I have a basic transistor tester, these provide very elementary indications of the transistor under test but at least provide a rough guide to the gain characteristics, type of junction etc
Hfe is indicated as 88
Vf is 185mV (much lower than Silicon, this is absolutely normal)
COSMETIC CONDITION:
NEW
CLEAN
It's like taking a step or two back in time! As though the "engineer" behind the counter had just handed me the device! Engineer? Yep, I met many staff in those vintage electronic shops who were studying for their degrees at the same time, working in the shop for "expenses" - these were the days when you could spend LOTS of time chatting to the guy behind the counter about interesting things such as circuit design, dealing with thermal runaway etc!
I have now placed this Ge transistor back onto the "bed" of Black foam and resealed my original packaging - I look after my components and always kept them in properly sealed packets.
