oldest semiconductors still in use

[josephkk]

But nobody makes them anymore...like their "audio" cousin, the 2N109. I
remember AM radio circuits that used a 2N107 as an oscillator/mixer,
another one as the IF amp, and probably 3 2N109s as detector/audio amps.

Cheers

Phil Hobbs

Double checked to be sure, the 2n107 is an audio device. The 2n170 NPN
was an RF device. I had access to these as a kid; also 2n207 and 2n270,
later 2n414.

The 2n109 appears to have been a higher grade (more reliable) audio
amplifier.

 

[josephkk]

Your data is way too new. Back in the day, the 2N107 was the 'RF'
model. 'RF' is a moving target!

Cheers

Phil Hobbs

It sure looked like the period data sheets i remember. Then again two or
three years then would have easily have made that difference. IIRC f(t)
for the 2n107 was under 1 MHz. Of course that could have improved over a
couple of years then also.