In reference to the change I made building the vertical dipole for AO-7 Mode A, I now have a better option that is working out great......the Moxon beam. I found a calculator for working out the dimensions at:
http://www.moxonantennaproject.com
This website has all sorts of ideas in making this simple antenna.
I just building one to see how well it would work in my situation here, I made my version using 1/2" PVC for a light weight frame and for the elements, #12 stranded electrical wire, which I zipped tied to the pvc frame. As shown in the picture, I just mounted it below my Arrow dualband yagi, at an elevation of only 8 ft. Even at this low mounting, and surrounded by homes, I am quite impressed with this antennas results. I would recommend this antenna to anyone wanting to try and work Mode A with a low price RX antenna.
http://i863.photobucket.com/albums/ab199/W6ZKHJOHN/DSCN0478.jpg
John W6ZKH DM06