Finals

Call 'em PA's, finals, or output amps, these are the last chance for the signal to get amplified before it is hurtled out into the world. Shown here are some partial schematics of finals taken from a wide variety of sources. Unless otherwise noted the input is on the left side, output on the right.

The circuit above will output 1.2 watts with a 13.8 volt power supply. Value of RFC not critical, but must be able to handle some current, try 15 turns of wire on a toroid core.

The circuit above will output 4 to 5 watts with an adequate power supply. The design shown is optimized for 7 MHz; the transformers may need a bit of modification to optimize for other bands. Provide heat-sinks for the transistors.

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