Jim Lux wrote in
:

....
http://www.amsat.org/amsat-new/echo/Echo_Linkbudget.php

Interestingly, the working on the above document ignores rx antenna gain in
the uplink calcs, which may mislead the beginner.

The spreadsheet has the uplink 2m rx ant gain at 2dBi, and includes a
somewhat unrealistic 3dB of tx line loss on the uplink. These compensating
factors deliver somewhat similar outcomes.

The 2m uplink margin with a 5W tx is huge, something less than 1W might
still be adequate for the proposed 6dBi antenna and say 1dB of line loss.

Owen