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But for the signal strength seeming to be misleadingly strong, let's take a super-clear example: channel 2 in Sacramento. The model indicates I should have a -2.8 dB NM...but this is for a 3 kW transmitter 76 miles away with the terrain blockages as shown?? Seriously?? Now...that signal has a 5-meter wavelength, but I don't think low-VHF bends that much.
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KFTY is 45.6 miles away; do you receive it?
For the same coverage area, VHF-Low requires less power than VHF-High, ignoring the higher noise level on CH 2-6, which the FCC did when it calculated power allowed by a transmitter. The FCC also assumed everyone would have a receiving antenna outside, in the clear, at 30 feet AGL.
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Is NM the only determinant of "viewability", or is the dBm equally important? Is NM stated in terms of a dipole reference? In that case, stacked Yagis should give you something better than10 dB extra martin, right? (Sorry for the newbie questions, but NM is a new term for me in this context.)
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Viewability is determined by the signal strength and signal quality at the input of the tuner. Signal quality is defined by SNR and uncorrected errors.
Most tuners will drop out a signal weaker than -85 dBm at its input.
I recently did a tuner sensitivity comparison between a 32" Sony and a Channel Master 7003 converter box.
http://www.avsforum.com/forum/186-co...erter-box.html
Yes, NM is stated in terms of a dipole reference. NM 0 is at -91 dBm, but if you don't have a preamp, you must have a NM +6 dB, to allow for the 6 dB average NF of a tuner. The report assumes the dipole is outside and in the clear. You should read the FAQs here:
http://www.tvfool.com/index.php?opti...ask=view&id=57
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Is this a common experience for rural, somewhat hilly areas?
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YES