20 Watt VLF QRQ CW transmitter(18.200 Khz) - AD5DZ CW Keyer, Audio Amp, 4 to 1 Balun, Delta Loop

[Chuck aa0hw]

Brief experimental setup using the AD5DZ CW KEYER, to directly send 18.200 Khz CW AUDIO to a 20 watt audio amp...from the audio amp output to a large BLUE IRON POWDER TOROID 4 to 1 balun - then to the input of a compact 21 foot long DELTA LOOP wire antenna with one leg of the delta loop connected to a series resonant capacitor(6uF)

This 4 to 1 balun and the size and material of the blue iron powder toroid, made a massive difference in transferring almost all of the 20 watts max that that this audio amp is capable of...to the input ports of the DELTA LOOP... in addition, more power was transmitted by the small delta loop antenna by adding a series resonant CAP to one leg of the DELTA LOOP...which increased the 18.200 Khz signal at the RECEIVE site by 10 db...

The receive antenna is a BIPOLAR TESLA COIL(@800 TURNS) with a massive NiZn - High Permeability FERRITE CORE(15 inch long, 1 1/4 inch diameter) connecting directly on one end to the sound card's LINE INPUT from a few turns around the primary TESLA COIL windings...

being able to send at this 18.200 Khz VLF Frequency with the AD5DZ CW Keyer software, really made the setup much easier to implement...