I want to add a lo-VHF dipole for channels 2 and 6 in Philly. Both signals are very strong but not very reliable with my RCA ANT751. Can anyone give me some tips on size, construction ideas, etc. My ANT751 is roof mounted but I was thinking of putting the dipole in the attic since both channels are over 60 NM(db) on my TvFool Report (and only 15 miles away). I use a CM 7777 preamp so I was thinking of joining the signals after the power supply to minimize signal loss from the rooftop. Comments?