Quote:
Originally Posted by LOTL
... Im curious as to why the signal strength will hold solid for a extended period of time at a particular level and then drop off or increase at other times.
Weather has been clear and cold here, so i dont think thats a factor.
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To the contrary, clear cold weather can be very much a factor. There is an atmospheric condition known as
tropospheric ducting. That's what the
Tropo means in your TV Fool Radar report. It is associated with high pressure systems and the still cold dry air that accompany high pressure systems. Normally, TV signals propagate just over the horizon. Tropospheric ducting allows signals to propagate up to hundreds of miles. This may or may not be a good thing. If it allows you to receive RF Channel 15 from 200 miles away, then it may a good thing. If it allows RF Channel 15 from 200 miles away to interfere with your local RF Channel 15, then it is a bad thing.
Here is the deal. My RF Channel 15s are mythical. Your TV Fool Radar plot indicates that you live in a poor reception area with many weak signals. You have multiple instances of local stations that use the same RF channel as stations about 100 miles away--or less. WMUR/ABC (RF-9) uses the same RF channel as WEDN/PBS. WCVB/ABC (RF-20) uses the same RF channel as WCCT/CW. WHDH/NBC (RF-42) uses the same RF channel as WSAH/MeTV. These are just three examples in your TVFR plot. Each of these stations may be received on a regular basis with a deep fringe VHF/UHF antenna. This phenomenon is not restricted to stations in your TVFR plot. What is more, tropospheric ducting is just one of several atmospheric anomalies that may allow you to receive distant stations. And remember, if you can receive the signal, then the signal may also interfere with another signal that you prefer.