This 50 kHz to 250 W circuit was found in an old RCA documentation. The transformer is a commercial type of the time and the output voltage is 80 to 90 V.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....