500mW CW TRANSMITTER




Q1:
2N3053, 2N2222, SK3265 or similar inexpensive general-purpose NPN transistor. I use a plastic-case transistor that came in a bargain-pack from Radio Shack - works fine. Use heat sink - try an alligator clip if you don't have a heat sink handy.

TANK COIL:
use a 1.25" diameter form (35mm film canister, pill bottle, etc.) and #20 - #22 AWG enameled ("magnet") wire. To make tap, wind L1 to the "tapped at" number of turns (see table below). Make a loop about 1 inch long, twist it a few times and finish winding. Sand the insulation off the end of the loop. This is your tap. After winding L1, wrap it with a thin layer of masking tape and wind L2 on top of the tape in the same direction as L1. Secure L2 with more tape and finish by sanding insulation off remaining leads. 

            L1:                               L2:

(primary/collector windings)         (secondary/antenna windings)
160m--60 turns, tapped at 20         160m-- 8 turns
 80m--45 turns, tapped at 15          80m---6 turns
 40m--21 turns, tapped at 7           40m---4 turns
 30m--15 turns, tapped at 6           30m---4 turns

XTAL: fundamental-mode crystal for desired frequency.