Six months after I purchased a TV6C analog television transmitter kit from eBay, I finally got the motivation to open the package and attempted the construction! Yes, the idea of having sort of a ‘real’ working television transmitter in my room was great, but the amount of time and efforts that will need to be spent has prevented me from trying the kit previously.
This is an all-in-one kit that provides you with everything from the PCB, capacitors, resistors and inductors to even the plastic box for the transmitter unit. Of particular note is the IF can-style RF transformer for the audio sub-carrier frequency (4.5MHz for NTSC-M in the US), which would have been very tricky to purchase.
This is the packaging for the kit:
The circuit is a low-power TV transmitter with separate video and audio input, and a 2N3866 power amplifier stage to increase the transmission range:
This is the full circuit diagram:
Completed circuit board
During my testing the completed circuit works beautifully with clear pictures on my Casio portable television. The transmission range is approximately 100m with no obstacles in between. The only disadvantage of this unit is the 4.5MHz IF transformer designed for the NSTC-M TV system in the US. This means that you will still be able to feed in a PAL video signal with audio, but the receiving television may not be able to play the audio properly unless it’s a smart enough to detect the TV system and audio subcarrier frequency separately. In my case, with the AKIRA player setup to output NTSC and the Casio EV-550B supporting NTSC-M, the setup works just nice.
In order to transmit PAL, you will need to find an IF transformer having the audio sub-carrier frequency of the PAL system supported by your television (5.5MHz, 6.0MHz or 6.5MHz). I am planning to scrap an old PAL television, find the part and try again
Another minor disadvantage of the unit is the single mono audio RCA input while most players nowadays output stereo. To overcome this, you will need a stereo to mono converter circuit:
The full manual for the kit can be downloaded here for those who are interested.