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I'm skeptical of a single-source anecdotal report. If 300 miles is reachable with a rooftop antenna -- well I should get 50 or 70 channels from my tower. I'll let you guys know in 2009.

Unless the "rooftop antenna" was mounted on the roof of his Cessna 150...

You joke about the Cessna. However, RCA had an ad in the late 1950s about how their portable TVs were "Jet tested". The TVs were loaded into a jet plane and operated as it was flying over the tower. Of course, they should have operated fine as the tower was less than 6 miles away.

Quote:

Originally Posted by andy (Post 1422592)

The hard thing with digital DXing is that you don't see anything until it works 100%. It's hard to know when you're getting close, or even where to look. With analog you stop when you see something in the snow. A lot of digital tuners don't even have any kind of signal level meter.

My 45" Sharp Aquos LCD has a dynamic bar graph signal strength meter built in as part of the on-screen Setup menu. A minimal 60-65% strength typically produces a picture, although at that low end there is occasional picture pixelation and freezing as the tuner strives to reacquire the signal. Anything above 75% is clear as a bell.

Even in the station's market, if their broadcast tower is being buffeted by a windy day, the antenna at the top can bounce back and forth by a substantial fraction of the wavelength of their channel carrier frequency. Digital TV does have some echo (ghost) cancellation references but it does have limits. Depending on how the ghosts are where you live, you could get momentary failures as ghost strengths and phasing changes as the tower moves in the wind. And things may get to be more fun as DX, but maybe not, the ghosts may get weak enough to not be an issue...

I live at least 70 miles away from the nearest station I receive if you don't count the local UHF station that's fed off a crappy microwave connection from another station that's nearly 100 miles away. With my rather large Channel Master VHF only antenna with a mast mounted amplifier I receive 2 stations Channel 8 and Channel 12 crystal clear, above the VHF antenna is a UHF antenna that's yagi about 5 ft long with a corner reflector and also goes through a mast mounted amplifier, I use RG-6 coax. These antennas are on top of a 40 ft mast and I live on a hill on fairly high terrain for this area. My UHF reception from stations in the same locations as the VHF stations is very marginal.

I went out on some of the websites mentioned in the thread and followed some links where I found a few signal contour maps. Somewhere I've read that I'll need to be in an area where I'll be able to receive at least a -60 db signal strength to receive digital TV. This area shows that the digital UHF stations that are associated with my present VHF stations are putting about -125 db in this area, me thinks over the air will go away for me Feb 2009.