Close

ADC board modified

A project log for 32MHz spectrum + SDR + FT8 in an FPGA

A 0 - 32MHz FPGA based Software Defined Radio (AM SSB FT8) by ready modules->cheap and easy Last add: Oct 6th FT8 VHDL GFSK modulator

guidoGuido 11/09/2022 at 19:550 Comments

To get some amplification, I modified the circuit in this way:

Now the overall amplification between VINA-VINB and INPUT_50_Ohm is approximatively:

 (2200/390 + 1) = 6,64 i.e. 16,5 dB                          16,5+8,4= 24,9dB better than the original!!!

Of course I lost bandwith, but it still remains flat well beyond 30MHz.

Please note that I also DC decoupled the input, to avoid that DC short circuited antennas (e.g. EFLW with BALUN) or power supplied antennas (e.g. Magnetic Loop or Mini Whip) could influence or damage the analog input.

Discussions