This simple VHF TV video transmitter will accept baseband video input, hence it can be driven by most CCD cameras and VCR video outputs. It ouputs roughly 80mW and when used with a 40cm telescopic antenna over 100metres range is possible. The transistor can be a BC108, BC546, BC337 or a 2N2222. L1 is wound on a 10mm air former. I have only used this with a monochrome video signal. To transmit sound just build the WBFM transmitter and tune it to the audio channel.
UHF Video Transmitter
This UHF Video Transmitter will radiate a UHF signal between 420 and 500MHz with aproximately 150mW Output. The range using a 35cm telescopic rod antenna is about 150m.
Q1 circuit is the 210 to 250MHz Oscillator and the frequency is determined by the variable 4.7pF Trimmer Capacitor. This stage should be very well sheilded to prevent frequency drift.
Q2 circuit is the frequency doubler moving the frequency into the UHF TV Band.
Q3 circuit is the Power Amplifier and Amplitude Modulated Video mixer. The 1K preset controls the maximum video signal. The antenna should be adjusted for best ERP using a diode wavemeter to indicate strength.
