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[QUOTE=&quot;tballister, post: 45321, member: 5087&quot;]I can offer my own personal experience that for stations east of me an upward tilt of about 13 degrees yielded a 5-6 point increase in digital &quot;quality&quot; as displayed on various DTV's.&nbsp;&nbsp; The antenna height is about 5950 feet, but the signals arrive via a pretty good knife edge at about 10000 feet.&nbsp; The actual angle involved is about 5.4 degrees.&nbsp; But I found that roughly 7 degrees of additional upward tilt improved things noticeably.&nbsp; The same wound up true for stations coming from the north for which there is not a signicant height difference.&nbsp; For that antenna is was something around 7 degrees that helped, but it was only 2-3 points, although repeatable.My theory is simply that the upward tilt puts ground reflections just a little bit off the LOS.&nbsp; I note also that the 91XG's mounting plate is intentionally designed such that the boom can be angled upwards at any angle up to maybe about 20 degrees.Yeah!&nbsp; That's cool.&nbsp; And another way to get a ready-made reflector is to leverage your metal roof - if you have one.&nbsp; Where I am they are quite common; the snow slides of 'em pretty well.&nbsp;&nbsp; I received a C5 VHF loop antenna from AntennasDirect for testing and popped it onto a 20' pole just to quickly see what I could see.&nbsp; At first I was at the bottom edge of the roof so there was no metal underneath the LOS.&nbsp;&nbsp; But then I moved along the rear edge of it, such that there was now some surface area of the roof below the antenna, somewhat emulating the bottom half of a corner reflector.&nbsp; I could find a sweet spot about 5-6' or so above this surface where there was more than a 10 dB increase in level!The games we play ....[/QUOTE]

[QUOTE="tballister, post: 45321, member: 5087"]I can offer my own personal experience that for stations east of me an upward tilt of about 13 degrees yielded a 5-6 point increase in digital "quality" as displayed on various DTV's. The antenna height is about 5950 feet, but the signals arrive via a pretty good knife edge at about 10000 feet. The actual angle involved is about 5.4 degrees. But I found that roughly 7 degrees of additional upward tilt improved things noticeably. The same wound up true for stations coming from the north for which there is not a signicant height difference. For that antenna is was something around 7 degrees that helped, but it was only 2-3 points, although repeatable. My theory is simply that the upward tilt puts ground reflections just a little bit off the LOS. I note also that the 91XG's mounting plate is intentionally designed such that the boom can be angled upwards at any angle up to maybe about 20 degrees. Yeah! That's cool. And another way to get a ready-made reflector is to leverage your metal roof - if you have one. Where I am they are quite common; the snow slides of 'em pretty well. I received a C5 VHF loop antenna from AntennasDirect for testing and popped it onto a 20' pole just to quickly see what I could see. At first I was at the bottom edge of the roof so there was no metal underneath the LOS. But then I moved along the rear edge of it, such that there was now some surface area of the roof below the antenna, somewhat emulating the bottom half of a corner reflector. I could find a sweet spot about 5-6' or so above this surface where there was more than a 10 dB increase in level! The games we play ....[/QUOTE]

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