In the end this counter should be able to measure frequencies up to 2 GHz. I am still waiting for the components of the prescaler (The MB506 and 3 7490 dividers). The design of the pre-scaler can be found on my second posting on this blog.
The main design is from India. Have a look here:
Previous year I built the PIC16F628A version and this counter works fine till frequencies of about 50 MHz.
Inside the counter