Detail of the Apollo Block II Command/Service Module VHF <a href="https://en.wikipedia.org/wiki/Scimitar_antenna" class="extiw" title="en:Scimitar antenna">scimitar antenna</a>, showing locations on the Service Module
NASA
1969-10-15
Apollo Operations Handbook: Block II Spacecraft: Volume 1 Spacecraft Description (<a rel="nofollow" class="external text" href="http://history.nasa.gov/alsj/SM2A-03-BK-II-(1).pdf">PDF</a>), page 2.8-55