I have two winegard 4400 4 bay antennas. Currently I have one on a mast at my house. I have multipath problems that the directivity of an 8 bay would probably help. I want to bolt them together with angle iron pointing the same direction.
My plan is to use 450 ohm window line to create quarter wave impedance transformers, roughly taking the 300 ohm terminals on the antennas and giving me a 600 ohm point. Then I will parallel the two 600 ohm points back to 300 ohms and use a balun to send the signal to my preamp.
My first question is what frequency to cut the quarter segments for.
At my house, the Baltimore UHF stations come booming in, so efficiency on their channels is not critical. If I had to pick the DC stations that most mattered to me, it would be on real 34,35 and 36. At the same time, there are stations from the DC direction as low as real 27 and as high as real 50 I would like to get.
If I wanted to make an impedance transformer assembly focused on 34-36, would I cut it for 599 MHz?
Is wanting to make quarter wave segments that would work from real 27 to real 50 asking for too much? That would be centered at 620 MHz.
The supplied velocity factor for the 450 ohm line I have is 91%. (I do not have the equipment to measure the velocity factor myself). If I did my math correctly for a 620 MHz quarter wavelength section, I would need to use 4.3” (4 5/16”) lengths of 450 ohm line.
The antennas are too wide to use the 4.3” segments of line to join the two. I have some Radio Shack 300 ohm twin lead (the kind with the thick black outer covering and the foam core). Can I use equal lengths of that to connect the quarter wave 450 ohm line segments to the antennas? Would I want the lengths of the 300 ohm line to be some specific length, such as 1 wavelength at the frequency of my 450 ohm transformers?
I would end up with:
Antenna 1-300 ohm line-450 ohm line-balun-450 ohm line-300 ohm line-antenna 2
(The two 450 ohm line segments would be connected in parallel to the balanced side of the balun).
I could buy a DB8e or some other 8 bay antenna, but I have the 2 4400’s, the 450 ohm line, the 300 ohm line, and balun already. All I would need to buy is some angle iron to hold the two 4400’s next to each other and parallel.
Without test equipment, is there anything I can do to optimize lengths of lines, spacing’s, etc?
Am I making this too complicated? Would I get similar results just taking the two antennas, putting a balun on each of them, and connecting them to a splitter in reverse?
Thank you for your help.
(Location details are in
http://forum.tvfool.com/showthread.php?t=13197 suggestions from that thread were noted, but there is a money problem preventing me from buying a DB8e.)