10-11-2019, 05:05 PM
(This post was last modified: 10-11-2019, 05:06 PM by Mike Watterson.)
Composition resistors are made of a mix of clay and charcoal/soot, hence go off badly when damp and with age.
If the push pull is transformerless and both same polarity, it's "totem pole", if NPN and PNP then "complementary push pull".
There are series type amplifiers. RF cascode is one type. It's quite interesting, used valves then transistors. Practically obsolete now with single GaAs transistors with 1V supply, 0.2dB noise and up to 200 GHz.
If the push pull is transformerless and both same polarity, it's "totem pole", if NPN and PNP then "complementary push pull".
There are series type amplifiers. RF cascode is one type. It's quite interesting, used valves then transistors. Practically obsolete now with single GaAs transistors with 1V supply, 0.2dB noise and up to 200 GHz.
