Matthias Bopp, DD1US has an extensive collection of sounds from Amateur Radio and other satellites on his website.

Historic recordings include Sputnik 1, Gagarin and Apollo 11.

There is a page devoted to clips of Amateur Radio satellites from Oscar 1 to Oscar 68, however, he doesn't have any recordings for some of the early pioneering Amateur Radio satellites including:

Oscars 2 to 5
Oscar 8
Weber Oscar 18
PoSat Oscar 28

If anyone has recordings of these satellites perhaps they could send Matthias a copy.

Sounds From Space
http://www.dd1us.de/historical%20sounds%20
from%20space.html

Sounds from Amateur Radio Satellites
http://www.dd1us.de/spacesounds%202.html

Matthias DD1US
http://www.dd1us.de/