The CSM High gain Antenna used to beam TV pictures on the S-Band frequency was rated between 10 and 20 Watts, mostly operating at around 12 Watts. (From a Bellcom 1969 Apollo 10 report)

The nominal signal strength decided for Lunar Transmission was also at 10 Watts (though the LM antenna on Apollo 11 was significantly weaker...I dont have the figures ready).

In all cases the size of the receiving antenna had a direct influence on the picture quality. Simply look at the DVD available from www.honeysucklecreek.net (or through me, send a PM for costs) to compare the various changes in quality from each of the 3 active Rx sites.

Over on the yahoogroups apollohoax site, Mike Dinn who was a senior technician/engineer at both Honeysuckle Creek, and Tidbinbilla Trackings stations devised an easy to read graph showing what was necassary to achieve a fake lunar sourced signal. For all intent and purpose this method is highly unlikely given the LEO objects required to pull off such a stunt.