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Finding Modern Equivalent of Obsolete Transistors

I think that it may have been mentioned, but I'm a little confused. Who actually still manufacturers semiconductors other than NTE?
 
dumptruck said:
Did someone tell you they are obsolete or something? Hundreds of companies.
Click to expand...

Actually there are some vintage IC's that are obsolete, but I could have been more specific. I just don't know of any company that has a more comprehensive selection as NTE does. I would be interested to know if there are other companys out there that manufacture vintage equivalents. I know that there must be several that make modern surface mount transistors and IC's, but I am mostly interested in vintage components.
 
945's are readily available.
On Mouser or
digikey just type in 2sc945 in the search box and voila!!

Ocassionally if the part is obsolete it will come back with a recomended sub but not always.
NTE site is good for specs for sub transistors. Use their cross reference to compare with better products.
 
2SC945's are $.08 at MCM. I like MCM for transistors. I avoid second guessing the designer with NTE parts. I've had them fail right out of the box.
 
No Joke. I did read the thread again and found these companys were mentioned: Mouser, Digikey, Newark, MCM. I recently replaced two transistors on a preamp board. They had C458 marked on them and 2SC693U in the service manual. Didn't find a cross for this part at any of the companys above, but did at NTE. There was no exact cross for C458, but were some with added letters, so used NTE 85's. Seems to work fine, but thought there might be a more appropriate replacement. 2SC693U crosses to NTE 199, so I'm wondering if I used the right one.:scratch2:
 
NTE is not a manufacturer (I got to know most of them in the 90's working for a clean room robotics company). They buy parts from whatever sources they can get, and remark them with their generic codes. For this reason alone (not knowing WTF you're really buying) I avoid them. They were caught up in a Chinese counterfeit semiconductor scandal a few years ago. Probably only a matter of time before they source from dubious Chinese suppliers again and hoze their customers. Even discounting that, and their prices, generic parts are fine for that old Philco TV, but inappropriate for High Fidelity audio gear.

Mouser, Digikey, Newark, and MCM are simply retailers. The first two I trust implicitly to source parts straight from reliable manufacturers. Newark is partnered with MCM, and MCM buys from Chinese sources that I'm not so sure about (but if you buy a part from the otherwise reliable Newark and it gets sourced through MCM, they make it clear from the beginning, so there's that at least). I'm always suspicious when MCM pops up a part that used to be made by Hitachi or some such, yet has been out of production for 15 years or more. Seems some Chinese manufacturer is simply churning out parts that may or may not meet the specs of the original and tossing some numbers on it. I've seen it 100 times or more and have bags of examples.

And if you're relying on that NTE cross-reference, be prepared to get bit in the ass sooner or later. It's laughable in its recommendations from time to time.

If you're working with Japanese semiconductors, you can get most specs here. That, along with noting the case style will get you started on finding a good replacement,
 
Detailman said:
945's are readily available.
On Mouser or
digikey just type in 2sc945 in the search box and voila!!

Ocassionally if the part is obsolete it will come back with a recomended sub but not always.
NTE site is good for specs for sub transistors. Use their cross reference to compare with better products.
Click to expand...


No they're not. No results.
 
This is getting rather confusing and turning into a 'who manufactures better transistors' discussion. I just need the replacement transistors for 2SC945 and 2SD234. If someone could tell me that, I will be glad.
 
Here's the NPN's I have at hand. I don't think any of them can be used as replacement for either 2SC945 or 2SD234.


512-KSC1845EBU :

DC Current Gain hFE Min: 400 @ 1mA @ 6V
Maximum Operating Frequency: 110 MHz (Typ)
Collector- Emitter Voltage VCEO Max: 120 V
Emitter- Base Voltage VEBO: 5 V
Maximum DC Collector Current: 0.05 A
Power Dissipation: 500 mW
Maximum Operating Temperature: + 150 C



512-KSC2310YBU :

DC Current Gain hFE Min: 120 @ 10mA @ 5V
Maximum Operating Frequency: 100 MHz (Typ)
Collector- Emitter Voltage VCEO Max: 150 V
Emitter- Base Voltage VEBO: 5 V
Maximum DC Collector Current: 0.05 A
Power Dissipation: 800 mW
Maximum Operating Temperature: + 150 C
Continuous Collector Current: 0.05 A



512-KSC2690AYS :

DC Current Gain hFE Min: 160 @ 300mA @ 5V
Maximum Operating Frequency: 155 MHz (Typ)
Collector- Emitter Voltage VCEO Max: 160 V
Emitter- Base Voltage VEBO: 5 V
Maximum DC Collector Current: 1.2 A
Power Dissipation: 1200 mW
Maximum Operating Temperature: + 150 C
Continuous Collector Current: 1.2 A
 
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