This is the "Elephant in room" for me, designing and building the analog part of the front end. I know the theory I can apply some intuition on top but in the end is open to experimentation. Because I took the "brilliant" decision not to have a mixer in the front end and directly sample (actually under sample) the RF now I have to deal with larger frequencies (the opposite of simple) and I saved the cents to spend the dollars. The VGA (variable gain amplifier) in front of the

A short analysis of the HAM Radio HF bands led me to the idea of under sampling the incoming signal and eliminate the mixer altogether here is my rationale The HAM Radio bands are quite narrow in comparison to my ADC Nyquist band (0-Fs/2) Checking the datasheet of LTC2314-14  it seems that is suited for under sampling because it has good full power bandwidth, so in theory is should be feasible to use aliasing in our favor and make the band limited signal to fall in our Nyquis

Below is a full project and Youtube video on how to design a shift register and display the state of the bits on the 8 LEDs on the board....

This article is about the first and very rough at the edges implementation of the Sinclair Spectrum on the Retro Board that I built. This...