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Discussion Starter · #1 ·
How much should an OTA signal change from morning to night?


I live in Bridgewater NJ and I am pointing a large radio shack antenna (100 inch UHF Yagi) located in my attic to Philly. Doing this give me rock solid 100's on both ABC and CBS. Its on the FOX, NBC, and PBS locals that I have trouble.


During the day all the way up until about 10pm I get a signal on FOX of about 30-44 (which locks in if it holds at 37) NBC at about 09-12 and PBS from 06-12.


I know that NBC is broadcasting off a side of a building so I am not so worried about that, but the strangest thing happens starting at around 10pm or so.


After 10pm the signals of NBC, FOX, and PBS start to increase first to about 27, then to 37 (which locks in) then to 44, then to the 55. After that each station seems to hit a max where FOX can max out in the 90's, PBS in the 60's and NBC in the 70's. This will go on for most of the night with the strengths fluxing from teh 50's to the maxs mentioned about.


Of course, the next day when I wake up - everything is back to the minimums where I can't get a signal (expect on FOX and that is only if it holds at 37)


Is this normal - I've heard of signals changing from day to nite but it seems extreme to me that a signal (like on the PBS station) can go from 09 when I walk in the door at 7pm and then hit the 60's after 10pm.


Could this be some late night testing of the antennas happening in Philly?


Any help from someone who has a better understanding of how signal strenghs work would be greatly apperciated.


-Keith
 

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Just the way it with propagation.


At night, the fog rolls in, and signals are "ducted" directly to you. Signals bounce around in the air/fog interface acting like a waveguide between you and the source.


When I lived on the East Coast, I used to get television stations all the way up the coast, as far away as Canada when conditions were right. All will fade away when the fog burns off.


Bob Smith
 

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Discussion Starter · #3 ·
Bob,


Thanks for the reply.


Not the answer I was looking for, but its nice to know the reasons behind the strange behavior that I am seeing.


At least I am able to get the king of HDTV, CBS, with rock solid 100 signal.


I am still holding out hope that the other stations will increase their power enough for me to get their signals. I assume I'll get NBC once they move to their permanent tower and I understand the the PBS station WHYY isn't broadcasting at full power yet. I believe that the Philly UPN and WB stations aren't broadcasting digital yet.


-Keith
 
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