"Jimmy" wrote in message .com...
Bought a literal bushel basket full of old CB amps for near nothing. Many
are tube type mobiles that use inverter power supplies. I am trying to
figure out what frequency the power supply oscilates. My plan is to get some
of the power supplies up and running using a TL494 and Power FETS. What kind
of transistors were used in thes things. Some of them look lie they were
stud mounted and others are obviously TO3. Any help would be greatly
appreciated.

Most of the transistors with the stud mount were PNP germanium in the
TO36 case. These worked as a miltivibrator, with the HV transformer
primary as the load. It depended on a feedback winding for operation.
With circuit tricks you could have the collector (case) at ground
potential.

These would oscillate in the neighborhood of 3-10 kHz, and usually
emitted a soft squeal when operating.

most of those amps were built as cheaply as possible, and I'd
seriously question the value of any of the componenets. A good source
for T-powered HV supplies is surplus two-way radios, such as the GE
Matr Pro, or Motrac.

Gary Hildebrand WA7KKP