Do you guys change outhouse transistors?

[Captain Kilowatt]

I did a search for "2sc458 transistor problems" and 99.9% of the results were from audio sights usually dealing with reel-reel audio aka audiophiles. That really makes me wonder even more considering most of them claim to be able to hear the difference in audio between using oxygen free copper speaker leads and just plain old copper wire.

 

[PoDuck]

I didn't check the transistor to see who manufactured it. I didn't even look to make sure it was a 458. I just went by the schematic and assumed it was. I must have been right, because it worked. I didn't throw it away, so when I get back to the shop Monday, I'll check to see if I can determine if they are Hitachi or Fairchild transistors.

It really isn't a huge deal to replace them though, since the replacements are less than ten cents a piece, and the 1845s are lower noise than the 458s from either manufacturer. If I were going to keep the radio myself, I probably would replace them all.

 

[Robb]

From what i'd seen on the net, it shows that it was bad materials/design that cause them to fail well before they should.

 

[nomadradio]

I'm not sure who made the small-signal transistors in the "outhouse" package. Might have been Hitachi. Seems to me we saw a lot of them on the circuit boards of CB radios they made for other name brands like Sears and JC Penney.

A long time ago.

Can't say I remember them being any less reliable than the more-familar round packages with the flat face.

Replacing parts that may or may not be bad because the risk of failure is high makes good sense. Just don't remember associating this package shape with chronic breakdowns.

73

 

[PoDuck]

Well, if it was bad design, Marantz, Sansui, Kenwood, and many others had bad design. They seem to age badly, even with little use, so I think it is something to do with how they were manufactured.

Anyway, I don't know if they are all made by the same manufacturer or not, and I'm not sure what causes them to behave badly, but I know I've found them to be the culprit in many an audio device on my bench. There is a pnp complimentary version that has similar problems. I don't remember the part number right off.

Anyway, for future reference, if you recap a radio, and it still has trouble that acts like a failing capacitor, look to these as a possible culprit.