I tested a camping dish with only 30-31cm with my POTY (patch of the year) patch feed. With 4-5Watt my signal is realy only 2dB lower as beacon.
This is the antenna I use
https://www.amazon.de/gp/produ…tle_o00_s00?ie=UTF8&psc=1
attached you see the antenna on my balcony.
Best regards
Frank