I recommend install the San Diego system , the HD7698P antenna , first and then at a later date the L.A system.
KSCI UHF channel 18 and KUAN-LP UHF channel 48 at 70 degree magnetic compass direction are the same programing.
http://en.wikipedia.org/wiki/KSCI.
KUAN-LP is weak signal strength.
With the HD7698P antenna aimed at about 136 degree magnetic compass direction , the KUAN-LP signal will be at a front angle to the antenna and the angle to the antenna weakens the signal strength more.
I think there will be enough signal for KUAN-LP to be received , if not , turn the front of the antenna more in the direction of KUAN-LP to receive KUAN-LP with out losing the reception of , KFMB-TV , KGTV-DT , and the weak signal strength KTCD-CA Univision , if you will like to receive Univision.
Its a balance of reception locations and signal strengths.
Most Digital Tv's have a signal strength meter and some Digital Tv's have a signal quality meter.
As a test to prove reception , connect to the Tv , not to the TIVo , Tivos are known to Not Have the best Digital Broadcast Tv Tuners