Digital Television Tests – Bulletin No 2

Update number 1, as at 21st January, was published in January Q-Bit magazine, recently posted to members.

In summary, the update included a block diagram of the digital test system and discussed the various factors influencing the quality of the radiated transmission, such as the exciter quality, adjustment of the power amplifier, and the impedance matching of the output filter and antenna.

Since update number 1, the linearity of the prototype power amplifier has been optimised into an impedance matched load, using both an unmodulated CW carrier, and a modulated spectrum, both centred on 506 MHz.

The quality of the prototype exciter, and of the power amplifier, and any necessary adjustments, will be tested using professional equipment during the coming week.