Loop antenna at upper left can be .25 to .5 inch ferrite rod from old AM radio about 6 inches long with 300 turns of number 30 wire over length of rod and cover with electrical tape. 1.5 kHz. signal is added to run in simulator.
The transistor is 2N3904. LM386 is IC amplifier. Battery supply can be 9 to 12 volts. Lower 8 ohm resistor on right is low impedance (less than 25 ohms) headphones.
Improve antennas of transmitter and receiver best way to improve rig. Power could be slightly increased.
