Joe:
Thanks for the update on your 91xg. Glad to hear that you are happy with your new antenna. It sounds like you are on the right track.
A horizontal stack of two 91XGs is probably you best next step. The stacking boom must not be metal.
The person you want to talk to is Calaveras on AVS
HERE
In these posts he talks about his tvfool report and the 91xg. You can see his stack of two in his avatar:
http://www.avsforum.com/forum/25-hdt...l#post24675667
http://www.avsforum.com/forum/25-hdt...l#post24660008
In this post you will see links at the bottom of the post for his antenna system and a photo of his 91xg UHF and VHF stacks:
http://www.avsforum.com/forum/25-hdt...l#post24621902
System:
http://images.aa6g.org/AVSForums/Antennas.jpg
Photo:
http://images.aa6g.org/AVSForums/Ant...F-FM130418.jpg
stacking hardware:
http://www.atechfabrication.com/prod...tenna_boom.htm
stacking thread:
http://www.highdefforum.com/local-hd...nna-setup.html