In 2000-2001 we constructed our first transceiver with a frequency synthesizer that is controlled by PIC16F84/88 microprocessor from Microchip. The VCO is based on integral schemes HEF4750V and HEF4751V from Philips.
Originally we used a microcontroller to control a VCO synthesizer. There were a lot of challenges with writing the program and testing the hardware. That was also the first time we wrote ASM code for PIC16F84 and we actually gained all of our initial knowledge here. Later on we switched to using the PIC16F88, which has a larger memory to implement more new functionality.
The final result was quite good. We had our home made SSB/CW transceiver with 10Hz step, which was able to work on two frequencies, as well as have an LCD and a keyboard for controlling.