We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a BC558 and the common 6 V relay, just by using this voltage in the supply.
This amplifier with two transistors for analog instruments was found in a Raytheon publication from the...
Using a ceramic resonator, it is possible to vary the frequency between 4.9 MHz and 5 MHz. The...
This operational filter configuration was obtained in a 1980s publication. The calculation is made by the...