What the hell were they thinking when they came up with this numbering scheme. The original Japanese transistors were 2SA733 and 2SC945. Then the Koreans (?) thought it would be a good idea to clone these as KSA733 and KSC945 but add the suffix "C" to have a center collector like the Japanese transistors. And why not just leave the first two characters off of the P/N. What could possibly go wrong? Oh Boy!I avoid the a733 and c945 BECAUSE these particular damn transistors are available with two different pinouts.
What the hell were they thinking when they came up with this numbering scheme. The original Japanese transistors were 2SA733 and 2SC945. Then the Koreans (?) thought it would be a good idea to clone these as KSA733 and KSC945 but add the suffix "C" to have a center collector like the Japanese transistors. And why not just leave the first two characters off of the P/N. What could possibly go wrong? Oh Boy!
And again I say, somewhat differently: In WHAT circuit positions? Each circuit position does different things, and must be analyzed for best fit parameters.So again, that leads me to original question... What's the best replacement for KSA733CLTA & 512-KSC945CLTA
The thing that I thought was out of hand is that since the transistors do not have 2S or KS printed on them, you do not know if you are looking at a KSC945 or 2SC945. A 2SC945 subs to KSC945C to get the same pin out. Not exactly brilliant in my opinion.The transistors concerned were originally NEC fabricated epitaxials.
KSC (Korean Semi Corp?) was simply a manufacturer code (a subsiduary of Silicon Transistor Corp - STC). Now it has gone on to mean of 'Fairchild' origin- maybe Fairchild bought STC way back and manufactured in South Korea? (what exactly happened with NEC's divestment of its semiconductor business relating to epitaxial transistors is anyone's guess and where Fairchild fitted in is interesting, considering the issues they had in the 1970s with their business arrangement with NEC) The 2SC945 had the NEC pinout and Sanyo(2sc4641), Toshiba (2sc1815), Mitsubishi (2sc2320) and Hitachi (2sc2308) had their own JIS numbers (idenitical) transistors some with their own pinouts.
ECB across the face was never the standard for Japanese T092s, it was just one of many- the most common.
The 'c' suffix was never needed because all the details on the pinouts were tabulated in Japanese Data Manuals that everyone had on their bench and you learned which manufacturers used what pinouts on what transistors. The 2SC945 has to be the most common T092 ever used.
There's nothing hard about it.
Ok, here's the "dirty secret":One of your (markthefixer) previous post on another thread for awm-062 rebuild. That why I asked about the 2 transistors.
Q3, Q4 SSC945-Q
512-KSC945CLTA to-92 eCb 50v .15a .25w 300mhz 40-700hfe $0.05 ea
Q5 2SA733-Q
512-KSA733CLTA to-92eCb 50v .15a .25w 180mhz 40-700hfe $0.05 ea
...since the transistors do not have 2S or KS printed on them, you do not know if you are looking at a KSC945 or 2SC945. A 2SC945 subs to KSC945C to get the same pin out. Not exactly brilliant in my opinion.