Do stations vary their power throughout the day?


Just hooked up a new antenna last night. Scanned with the TV and got almost 50 stations. This morning I noticed most of the distant stations are not coming in at all. I am located in the Toledo Ohio area and was able to get most Detroit stations and several Cleveland stations. Now Detroit and Cleveland do not come in. I am wondering if stations bump their power in the evenings?

Signal propagation is what changes. In some areas of the country slightly enhanced signal propagation from temperature inversions can be quite common, and somewhat predictable. Tropospheric ducting is a bit less common but does occur regularly in some areas of the country.
Tropospheric DX Modes



Do Stations Vary Their Power Throughout The Day?

.....I am wondering if stations bump their power in the evenings?.....
Like Steve said, signal propagation can change. Years ago, when we were still NTSC, I erected a second antenna at my parents farm, so that they could get TV stations from both Duluth MN and the Twin Cities. In the early morning, during certain times of the year, the Twin Cities stations came in great. Some times they vanished during the day and then re-appeared later.

Some radio stations change their power, but I have never known a US TV station to do that.


Hello Folks, I have just joined for this very same problem looking for a answer to the problem that I am having. I bought a FP-9000 150mile or so antenna with rotation controll. From 10pm to 7-9am the next day I get about like the poster said 50 stations and well into the gray zone 90 miles away. After 10am I am down to about the local 6 stations. I thought it was a heat/temperature specific problem with electronics and contacted the seller to no available solution. I contacted Digitalstream Inc and asked about my converter with no solution except a reset which didnt work. I thought about returning the antenna , but wanted to make sure if anyone else had a temperature or time of use problem like i have. The question I have now, is there a antenna/equipment available that can overcome this problem of tropospheric propagation. (oh, one more thing I get the same channels between 10pm to 10 am whether its 20 ft above ground on the roof or just on a tripod about 5 feet above ground) Any solutions, I also went to Tvfool if anyone needs the data to look at. Thank you very much for having me on this forum.(i hope i posted this correctly)
Gardog :eek:


The major contributor to daytime loss of distant TV reception is... THE SUN. At night the background RF radiation levels are lower because the RF from the sun is shielded by the earth, but when the sun comes up and as it rises in the sky the background RF rises and drowns out the weaker signals that were usable at night and early morning and late afternoon.
While Tropospheric Enhancement signals are quite common in some parts of the country. A phenomenon I am quite familiar with. This takes place in areas where the signal is right at the edge of what might be receivable all of the time. True Tropospheric Ducting is so rare in my part of the country that I can't say that I've honestly experienced it. I have certainly read that ducting is quite common in some parts of the world.
Knowing what antenna your using makes me suspicious of the built in amplifier being flaky, but if the signals are the ones in grey on a TV Fool report I would have to think atmospheric conditions are playing a part in it.
Jim5506 you brought up an interesting point. I'm not certain how big of a factor solar noise is at UHF/VHF television frequencies. I've always thought that temperature inversions played a far bigger roll in somewhat predictable daily changes in UHF/VHF signal propagation seen in some parts of the country.


Contacts maybe? Elemental forces or Gremlins, Menehunes, and Leprichauns

Hi folks, We are having a heat wave out here in the Ok, Mo, Ak, and Ks 4 corner area. I originally thought I had a bad contact somewhere in the new equipment that was being warped to material limits by heat expansion and cold contraction which occurs. I havent cracked the case yet with a phillips, but I have seen weirder things happen with moisture in this humid area after the heat goes away and the droplets start to form to include gremlins in distributors on tractors. I didnt pay alot for the this FP9000 device, it is a kinda cool sci-fi looking sort of B-rated laser gun movie prop at first sight, so I didnt expect much especially coming from china. But when the stations came in I was really impressed. But then was immediatley let down to see them go the following morning, it actually would be the perfect answer I was looking for, if it worked 24-7.Right now its only 12-7. So now I think I will for giggles crack it open and look into the little spaceship and see if there are any gremlins in there holding the contacts apart. - LOL
PS. Another thing that comes to mind is if a local station is interfering with the waves at those times particular times. We do have 3 tall monopole towers with in sight about 1 mile up to the north. I will have to call them and see if they are flipping the switch at those times. Wouldnt that be just terrific :/


The above post is mine folks, for some reason it didnt take correctly when I thought I signed in. So anyway, I cracked the case and I couldnt find anything that looked out of the ordinary.So I did some in depth reading researching the "Antenna Height and Communications Effectiveness" Second Edition by By R. Dean Straw, N6BV, and Gerald L. Hall, K1TD under Ham radio equipment operations and found this all very helpful and interesting. For one I now know the atmosphere is like a mirror to all radio waves and affects not just our tvhd waves, he he he. A little wake up for me. So anyway the article is and seems very interesting to read. I wont put a link because I believe that is against forum member protocol (I think?) but by the shear title you can find it on the net. Very interesting stuff for this freq'n newbie. - LOL

Fringe Reception

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To establish dependable reception it can require many hours of 'hunting' for the best location to mount your antenna. It will take hours of moving your antenna up/down/right/left and 'rescanning for new channels' and that is how its done. An option is to hire a REAL antenna installer who will use a signal quality meter to determine the best antenna location.


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