Most stereo receivers have both a 300 ohm (balanced input) and a
75 ohm unbalanced input for the antenna (these impedances are "nominal").
If your receiver has only a single input for the 75 ohm antenna, you may
assume that the other input is the chassis.... Just connect the braid of
the coax to the chassis ground terminal and everything should work fine.
Mark
Dr. Mark H. Shapiro
Physics Department
California State University, Fullerton
P.O. Box 6866
Fullerton, California 92834-6866