My graduation thesis - a 144 MHz Allmode Receiver

This page was last changed on 21.04.2005

My graduation thesis: A 144MHz FM/SSB receiver

After I had developed a couple of short-wave and VHF-FM Receivers in my spare time, I decided to develop an allmode Receiver for the 144 MHz amateur radio band as my university graduation thesis. This receiver has to be able to receive frequency modulated signals as well as single sideband (SSB) amplitude modulated signals at 144 MHz. The project was supervised and evaluated by Prof. Dr. Ott at the Georg Simon Ohm technical university in Nuremberg, Germany. All copyrights are to the university which means that you must not use any of these circuits for commercial developments.

If you should be interested in even more details than given below about the circuits or about the measured data, I will be happy to give it to you on your E-Mail request.

Pictures form the inside of the Receiver

Upper part (demodulators, AGC, frequency counter)

Lower part (LOs, PLLs, preamplifier, first mixer)

Close-up pictures from the modules

6 MHz VCO

36 MHz PLL

96 MHz PLL

Preamp and first mixer

Variable gain amplifier

FM Demodulator

SSB Demodulator

Frequency counter