Receiving the microwave ‘beam’ and getting back the originating AF is pretty straight forward provided you choose the correct components. Parts needed:
Universal LNB (used for receiving analogue TV)
A few passive components
Low Noise Block-downconvertor This is kind of like a more complicated aerial that receives the 10GHz ‘beam’ then down converts the frequency before going into the satcan via sat cable terminated with F-connectors (typically). Most LNBs work and most work very well. Look for a universal LNB which usually receives frequencies between 9.75 and 10.60 GHz. The picture below shows a common (although rather old now) Cambridge universal LNB which seem to work really well.
This is the main component in this system and can be obtained from TV satellite receiver boxes however you will need to work out which pins do what yourself as they vary with the manufacturer of the box. The picture below shows a Sharp BSFA75G08 tuner (satcan)
The IF is fed from the LNB into the satcan which will then demodulate the initial carrier from the gunn source, extracting the audio where it then gets amplified to bring it up to the correct levels. There are many different satcans out there and all have different pinout configurations which can be very hard to find and sometimes are kept secret by the manufacturer.
In most cases the satcan will require a small external circuit which can usually just be soldered onto the pins with no extra PCB. The circuit usually just provides the right pins with the correct voltage using voltage regulators and also a few resistors and caps for audio and tuning. You may find that some satcans have a low audio output, in which case you will need to a basic op-amp or audio amplifier circuit.
The BSFA75G08 (below and above) requires 12v to operate. See the diagram below:
This is the wired satcan using the above schematic. This is now ready to use:
Note the 7812 can be soldered onto the case
It is always best to use a screened type cable when dealing with audio (e.g linkbox to gunn module) However from the LNB to the satcan receiver a coax cable should be used, terminated with F connectors