This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power supply and common 100 mA relays.
This amplifier is from a May/April 1969 Popular Electronics. The components are from the period and...
This circuit may be used in IF steps of dual-conversion receivers, i.e., a type of receiver that uses...
This 555 IC circuit was found in the November 1994 issue of Radio Electronics magazine. The...