This circuit generates signals for adjustments in FIs of 10.7 MHz. The transistors can be BC548 or equivalent. We found this configuration in a documentation from the 70s.
This configuration with the LM383 appears elsewhere on this site. The circuit shown was obtained...
This signal attenuator was suggested by Electronics Now magazine in April 1999. The circuit is...
The voltage gain of this DC amplifier is 100 times, given by the relationship between R2 and R1....