Video Transmitter Sender Circuit Xtal - UHF
UHF Crystal Controlled video sender circuit Transmitter can be received
on a small portable and tunable battery operated TV set that can be
found in most thrift shops and flea markets. It uses a 55 MHz 3rd Overtone Crystal operating at its 8th harmonic at 495 MHz or Channel 18.
L1 and L2: Use the smooth side of a 1/8th inch drill bit and wind 2 tight turns using # 22 Magnet wire.
Adjust C1 and C2 to bring the picture on the screen and then adjust C3
for a maximum power output and clear signal. The antenna is around 12
inches of stiff wire. Battery supply can be anywhere from 4.5 Volts to
around 10 Volts. Any small video camera will work just fine.
The original crystal used was a DigiKey CA-301 (Part Number) SE3456-ND 55 MHz 3rd overtone. If you cannot find this crystal, use any equivalent that has an 18pF Load capacitance, 3rd
overtone, with an ESR of 80 Ohms. Other frequencies can be worked by
matching an overtone to one of the TV video frequency channels since
the three tank circuits will tune over a large area.