Multipurpose temperature control (CB21368E)

This circuit was found in a 1967 RCA SCR manual. It uses period components that can be replaced with modern equivalents.

200 MHz Amplifier (CB16666E)
This circuit is from a specialized documentation in 1992 FETs. The L1 coil has 0.07 uH with...
Symmetric 50 mA Regulator MC1568L (CB15327E)
The LM1468L can also be used. The circuit is from Motorola's Linear Interface ICs and the...
Frequency Doubler (CB4868E)
This low frequency doubler requires a 50 mV signal at the input. The circuit is from an old...