Found in 1965 Radio Shack documentation, this circuit has a crystal phone output in the 14.8 kHz range. The coil consists of 200 turns of wire 25 in a 1.5 m side square.
This circuit was found in a QST from the 1990s. The circuit expands the scale of a 10V instrument to...
This 8 ohm output amplifier was found in a 1968 Motorola publication. The circuit uses transistors...
This general-purpose preamp configuration was found in the 1960 Mullard transistor reference...