Tim de P shows up @ PSW

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thermionic

Well-known member
Joined
Jun 3, 2004
Messages
1,671
Hi,

One example: http://recforums.prosoundweb.com/index.php/m/421937/0/#msg_421937

I'd love to know what these 1,500 hFE transistors are. I don't think I've measured any small-signal devices that exceed 7-800 regularly. How does he get one device to dissipate 100W? It must be running pretty hot, right? How hot will a T03 dissipating 100W run? I'd imagine 80+ deg C, maybe over a hundred. 

Click on his profile and check his input to the Fairchild thread. Fascinating.

Justin
 
I should've clarified: I wasn't referring to power devices with the hFE comment. I haven't been made aware of low-noise transistors for small-signal apps such as preamps etc that measure such high hFE. The Japanese epitaxial transistors favoured for use in low-noise circuits rarely have more than 5/600 hFE.

J
 
thermionic said:
I'd love to know what these 1,500 hFE transistors are. I don't think I've measured any small-signal devices that exceed 7-800 regularly.

Fairchild claims that 2N5089 has maximum hfe of 1800, with Fn = 2 dB with Rs of 10K. That's not regular hfe of course.

OTOH, I'm deeply disturbed by mr Paravinchis' clam that folowers are nofeedback topology. Maybe, if we completely reinvent definition of feedback.

cheerz
urosh
 

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