Mila OK1UFL shared his experience about assembling and using a VK3CV transverter for 122GHz. Mila tested also a few 10MHz oscillators to improve frequency stability. He used a camping 40 cm offset dish and is nice to view how to find focus.
Link to the original article in the Czech language (use google translate options or similar): https://ok1em.blogspot.com/2021/02/test.html
Picture: from article