"Greg \(Strider\) Moore" writes:

The LM was under insane weight limits, they were shaving heads off
bolts, etc. Why was the heavy radar on it, and not the CSM?

Completely guessing:

It simplifies the search problem. They had a pretty good idea of where the
CSM was, but not necessarily where the LM would be.

And they probably had the electronics perform double-duty with the landing
radar.

No on the 2nd part.... See http://www.hq.nasa.gov/alsj/alsj-LMRadars.html
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433