I did the same and a bit more. My main goal was to get better reception on Channel RF 50.With the cold weather approaching fast and tropo finished for the most part, I decided to finally try stacking my 91XGs atop my tower.
I'm in Otsego County, New York. I used a Winegard antenna coupler # CC-7870 which is basically just a diplexer put into a weatherproof plastic box along with a mast-mount. I tested it with a vaious brand diplexers also and they all worked basically the same. None worse and none better.Nice setup! Where are you located? And you say you used a diplexer to combine the two 91XGs?
I tested each antenna on that mast by itself and then with the others with various spacings. I wanted to make sure I didn't "rob Peter to pay Paul" while adding antennas. I did not detect any difference on any antenna as long as spaced two feet apart. That's the vertical boom to boom distance. I wanted to space then as close as possible to leave more room on that mast in case I added more antennas later. So, I don't know what to tell you. Most what you read will warn you to have at least 4 feet. With my stuff? I've got two multi-antenna installations and on each, two feet has been fine.I agree it is a nice setup. I was wondering how much higher your 2 91XGs are above the 2 VHF antennas?
I tried putting my 91XG above my VHF antenna and hardly got anything. When I pulled it down and moved it about 8 feet to the side at about the same height as the VHF antenna it did much better.
Thats the one configuration I havent tried, yet, I always wondered about that, I read about the math behind it somewhere, its quite something!If you take two 91XGs, stacked vertically, and move one forward about a foot, reception spikes up quite a bit. I tested this just holding by hand. I wasn't about to try to make a mount though, to hold them that way
Well, overall . . . I find setting up dual antennas to be kind of depressing. My first try was with those two Winegard 9032s. I tried every just about every configuration and no matter what I did, I couldn't not get two antennas to work as well as one.jdemaris,
Thats the one configuration I havent tried, yet, I always wondered about that, I read about the math behind it somewhere, its quite something!
I was too "discouraged" to try to actually set this up...think it should be modeled first!