I find it horribly inaccurate since it doesn’t take into account receiving height. What height are they calculating for? Set-top first-story height? Rooftop? Tower top? At the dirt? I know they didn’t compensate for the 20 ft altitude change between the end of my driveway and the front door of my house.
The exact position of the receiving antenna dictates a LOT. A couple years ago, with my scanner and a telescoping antenna, I could hear 1 UHF station’s audio at my mailbox (low, at the road) Near my house, 4 ft AGL - 3 Inside my house, 4 ft AGL – 1 (I watched 9/11 news off this station using set-attached rabbit ears, go figure). Oddly enough, not the same station that I can hear at my mailbox (this station would be very non-LOS at my mailbox) At the ‘tree line’ on my tower – 7 150’ up my tower – a whole hell of a lot more (all high power stations from Tyler/Lufkin/Houston/Dallas-Ft Worth/Austin/Shreveport/Beaumont [within 250 miles or so]). Some were very faint, but definitely there (and this is with an Omni antenna and a half-deaf Uniden scanner…), some were stomped on by local low-power stations. The issue at that height is the antenna being directional enough to isolate on-channel noise. Now, the real question is, how bad does Fresnel affect DTV vs analog. I betcha you’ll have horrible problems with DTV signal in areas that tend to ‘ghost’, where analog TV was perfectly watchable/listenable, just somewhat annoying. 9901 Sweetwater, Houston, TX 77037 (house where I grew up) had this problem. As downtown Houston “swole” in the late 70s/early 80s ghosting became more and more of a problem. All we could do is kick our antenna farther west and add a variable signal attenuator (ie ‘ ghost filter’) - didn’t help a whole lot. JS From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Ralph S. Turk Sent: Friday, February 20, 2009 8:19 AM To: Repeater-Builder Subject: [Repeater-Builder] OT DTV Good morning All The following is a new FCC web site for DTV Follow instructions carefully. Wait for the program to calculate info. Seems to be one of the best. Confirms what I know from working in the TV business for 30+ years. Last several installing DTV. http://www.fcc.gov/mb/engineering/maps/ Ralph,W7HSG
