6SN7 Preamplifier (T1105E)

This preamp circuit has a typical configuration as found in a 1946 publication. Supply voltages are indicated.

100 Hz Second Order High Pass Filter (CB25815E)
This filter with the 741 op amp was found in the February 1995 Electronics Now magazine. The power...
Charger and No Break (CB4138E)
Suggested by an old American documentation the circuit below keeps a battery charged and at the...
45 MHz FI amplifier (CB8414E)
Found in documentation from the 90s, this circuit was used in communications receivers of the...