I don't consider myself an expert but johnnyx test did work. I started with a 170v dc supply, AC mains rectified for quick and dirty, thru an mpsa92 ccs and varible supply I was ellated to find that his suggestion worked. Between 112 and 116v the xstr slowed and stop increasing vce.
This suggest maybe a 2n6338 or like transistor.
john curl
If I get a little understanding I can find which polarity the trannies are even thier compsition, wow that makes feel good, two of the easist things to find, are you calling me an idiot , lol.
This suggest maybe a 2n6338 or like transistor.
john curl
If I get a little understanding I can find which polarity the trannies are even thier compsition, wow that makes feel good, two of the easist things to find, are you calling me an idiot , lol.
Unknown Transistors
HI
I can't help with the transistors but the unit looks very much like the voicecoil driver in the old Honeywell disk drives I used to work on many years ago. 200 Megabytes capacity on 10 largre platters and the box the size of a small washing machine. How things change.
Rob
HI
I can't help with the transistors but the unit looks very much like the voicecoil driver in the old Honeywell disk drives I used to work on many years ago. 200 Megabytes capacity on 10 largre platters and the box the size of a small washing machine. How things change.
Rob
The transistors are definitely "house numbered" units from Motorola circa 1978. They may be selected for breakdown voltage, high current gain, or they may even be loosely characterized "floor sweepings" to reduce cost. Who knows, as the company that comissioned them has probably lost the records and may not even be in business any more. I sorta agree with John Curl. With silicon as cheap as it is, it's not terribly productive to waste a lot of time trying to characterize unknown transistors. If they came from a power supply pass bank as I suspect (in 1978, the boat anchor linear supply was still king), they're probably something from a slow and rugged process like the 2N/MJ3772 series from Motorola. The fact that they're in aluminum cases is a dead giveaway that they're old devices, as people went to steel cases later on to reduce costs. The steel header is also a more stable platform for a big piece of silicon than is aluminum.
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