Signal Strength Indicator Behavior On "Fringe" Channels

[ChrisAntennahead]

Location/Signal: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d4033f6f24debd5

Setup:
AC HBU-55 mounted facing 226deg south west as per the above resume. 50' of RG6 from antenna bridged to former cable TV drop(10' RG6) which runs into house to my CM-7000 D/A convertor box.

Issue:
On what I call "fringers" - channels that do not indicate 100% signal strength on the CM-7000 meter the signal strength goes up and down violently(for lack of better term.) IE: WLIW 21 within a few second timespan it may go from 60% to 20 to 50 to 10 to 65 back down to 30%.(It seldom blacks out, but this meter behavior is unnerving!) By the way I fully accept and can understand *some* movement on fringe channel strength levels - if it bounced up and down all the time 60 to 50 to 60 percent that's what you'd expect.

The cables by eye appear to be in new or reasonable condition and all connections are tight. Standoff loops are employed by the cable going down the mast.

The "roller-coastering" signal strength indication is irrespective of the temperature or weather, and it doesn't matter if it's calm outside or gale force. This condition has persisted as long as I have had my setup as described above. Those channels that are 100%(CBS, NBC, Fox, ABC7, My9, CW11 etc) stay 100% practically all the time regardless of wind or precip.

Thanks for any help/suggs you can lend me!

[No static at all]

The CM7000 does tend to give unrealitically high readings for weaker stations from my experience. If you only see an occasional dropout, it may be unavoidable.

Any airports nearby?

[GroundUrMast]

The symptoms are consistent with multipath and/or edge-path propagation. WLIW is LOS, so that leaves multipath.

As a test, what happens when you aim at WLIW (183° compass)? Your antenna is far more directional than some smaller antennas. You may be receiving a strong reflected signal from the SW (multipath).

[Electron]

Install a Winegard HD7000R antenna aimed at about 240 degree magnetic compass. The HD7000R is a all channel antenna that will receive , VHF low band channels 2 thru 6 , VHF high band channels 7 thru 13 and UHF channels 14 thru 69. Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html. The HD7000R antenna is not a strongly directional antenna and Will Receive tv transmissions from other directions. The HD7000R does do a fair job of reducing multipath ( reflected signals off of , buildings , hills , mountains , trees and etc. ) because multipath is usually weaker then main signal and is out of timing phase ( arrival time ) at the receiving antenna.

[ADTech]

The HBU-55 is quite directional. If the antenna is not aimed well enough toward the direction of the weakest signals, the antenna will reject them (by design).