The complete analyzer:
Signal left to right: Input low-pass filter (green), mixer (blue module), IF1 filter (big black brick) ,mixer (blue module), IF2 amplifier (green module), IF2 filter (tin box), log detector (tin box) ->arduino analog input
Below two adf4351 modules (black PCB's)
The prototyping board is temporary till I get an Arduino Due (3.3Volt) to get rid of the 5v->3.3v resistors
The IF2 filter. relays to switch, ceramic for 300kHz and chrystals for 15kHz. Not very beautiful but performance is good.
The log detector, hope you can see the 0602 components. Its loosely based on the AD603+AD8307 reference design but with single sided supply of 12 volt.