Test reception with the antenna alone, outside clear of obstructions, higher is better. The RS amp may be doing more harm than good... the attic may be another impairment that is easily avoided.
http://forum.tvfool.com/showthread.php?t=13646
What does a TV Fool report based on 25' AGL look like, compared to your fist post?
I have seen the Y10713 serve as a UHF antenna when a preamp is located close to it's terminals. My theory is that the amp isolates the high SWR of the Y10713 (at UHF) from the line and so it sort of works.
I would not depend on the Y10713 alone in the San Diego market. I'd opt for a UHF antenna such as the Antennas Direct DB4e + Y10713 + UHF/VHF combiner. If a distribution amp is needed, the CM-3410 would be my choice for it's added gain and lower noise+distortion.
(ditto ADTech's suggestion re. the FM trap)