How to build an advanced TV transmitter with sounds?
This schmetic consists of the two sections: the one seems to be a video transmitter while the other is for audio amplifying. In fact, however, these are both transmitters. The main one generates video carrier while the smaller one generates the exact 4.5 (5.5 in some countries) MHz FM audio carrier. When it is supplied to the main section, the conbination generates the audio carrier that is the total of the video frequency plus 4.5 MHz (this is the same in the US but different in other countries: 3.5 in the UK, 5.0 in Italy, 5.5 in Australia and so on: see the channel plans). In the Japan TV plan at the 2nd channel, for instance, the video carrier is 97.31MHz and the audio carrier is 101.75MHz. Therefore 101.75 - 97.31 = 4.5.
I have been trying to design the 4.5 MHz transmitter without any special tools such as a frequency counter. So far, I didn't succeed in. In order to get the exact 4.5 MHz, you have to use a frequency counter (you can use a tester with such a function). Also, you have to be patient to get the 4.5 MHz by your cut-and-try works. I will explain how to do:
(1)The main section and (2)The audio section.