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Two weeks ago I installed an antenna in my attic (GE 33692) in order to receive stations that are approximately 45 miles away. Things worked fine in clear weather, light rain and moderate snowfall but one morning there was dense fog and signal levels were lower across the board. Most stations still locked in but several didn't. The interesting thing was that all stations intermittently dropping out or pixelating were Hi-VHF channels.

I am wondering what the right fix for this is. Will a mast mounted pre-amp help or will a different type of antenna be the correct choice (perhaps a high gain Yagi?)? Unfortunately an outside antenna is out of the question for me.

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  • Is outdoor mounting an option? The higher the frequency, the more objects like the roof will interfere with the signal. Especially if your roof is metal.
    – ArchonOSX
    Feb 23, 2018 at 18:07
  • Outdoor is not an option for me and roof is asphalt shingle. Not ideal but those are the options I'm stuck with for now. So far the dense fog is the only thing that has caused dropouts. As the fog lifted so did the signal.
    – Greg
    Feb 23, 2018 at 21:59
  • What you are experiencing is normal for microwave transmissions - fog is moisture - Weather Radar uses this scatter back to 'see' clouds. The signals from the station are being degraded by the fog - scattered back and dispersed. A pre-amp will help however your S/N ratio might have an influence and the Auto Gain of your TV tuner might attenuate the signal - lowering it to original. Look for a decent gain pre-amp with a very low Signal to Noise ratio; in your scenario S/N ratio is much more important factor than how much gain the amplifier will have.
    – Ken
    Feb 24, 2018 at 3:41
  • Thanks Ken. Your explanation makes sense and I am going to start looking for pre-amps with solid S/N specs. Seems signal quality is key in this situattion.
    – Greg
    Feb 24, 2018 at 13:36
  • If you find the right amplifier, it might help, but I would try a better antenna first. The main problem with amplifiers is that they also amplify the noise your antenna is picking up, so the signal to noise ratio might go down, but it can't go up. They're great if you have a long cable run and you're worried about degradation between the antenna and TV. And they can also help if you have a very weak signal without much noise, and you need to boost it a bit to overpower the noise in the TV tuner. A better antenna, on the other hand, can easily improve the signal to noise ratio.
    – mrog
    Feb 28, 2018 at 22:31

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An amp will probably make things worse, not better. Modern TV signals are digital, meaning they are compressed. But their new compressed nature also makes them highly susceptible to interference (such as your fog).

In older analog TV signals, the problem was often a weak signal. An amp could help reduce that loss between the antenna and the TV. But digital signals are often made worse by amps, because they introduce a small amount of interference. As such, you lose information and, thus the signal entirely (digital cannot make use of partial information like analog could).

I had to set one up for my mother and found that the amped antenna performed worse than an un-amped antenna. The only time you generally want an amp on your line is if you need to make a very long run of wire (if you're considering it, I'd just buy a separate un-amped antenna for the additional TVs).

Something else to consider might be an external TV tuner. TV manufacturers often skimp on the ones they install. I've even seen some that work with your wifi so you can get a solid signal in one location and then broadcast it over your house to streaming devices.

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  • Good information here too. The external tuner route is not something that's come up before so I may add that to my list of things that I'll try. Unfortunately I will have to wait for dense fog to really know if any one solution cures the problem as my current un-amped antenna arrangement works well enough otherwise. Watching the tuner indicator shows that signal strength varies in adverse weather but the two TVs have been able to cope - except in fog.
    – Greg
    Feb 28, 2018 at 14:29
  • If you want to experiment, you can simulate fog by putting something in front of the antenna that will attenuate the signal without completely blocking it. I suspect a wet towel would work, but your mileage may vary. For best results, keep it at least a 3-5 feet away from the antenna. But it your attic is as difficult to access as mine, you might just want to wait for another foggy day.
    – mrog
    Feb 28, 2018 at 22:39
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You could simply install a higher gain antenna, this basically means the antenna "listens harder" but they tend to be more directional/worse at receiving from places other than where it points. This would be a pretty easy swap and since antennas are cheap, you could experiment with another design to see if one works. Gain may not be advertised, but ones with a higher range specified will be higher gain.

Also, are you pointing the antenna at the origin of the stations you care about? It's easy if you are in the suburbs and all the signals originate from a city, but harder if you are in the middle of several stations.

I've also seen mention of using a splitter to combine two antennas, but haven't tried it myself. This might be helpful if you can't solve it by simply using a single antenna, but would be more likely to result in frustration and trial & error.

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  • "Gain may not be as advertised.." I am getting a clear sense of that in all that I have been reading! That's one of the reasons I am a bit lost here. I will probably end up trying another antenna as well as a preamp unless I get a clear result from the first of either that I try. I did spend a bit of time aiming the antenna when I first put it in. RIght now it is aimed where the desired signals were strongest. Thanks for the response and although it will take me a little more time I'll be back when I am done experimenting.
    – Greg
    Feb 28, 2018 at 14:23
  • If you have a high gain antenna, you have to aim it pretty carefully. I have a yagi style TV antenna in my attic that I picked up a Walmart for under $50. It works really, really well if I aim it within about 5 degrees of the transmitter location. Aiming is a process of pointing the antenna, stepping back at least a few feet so your body doesn't affect the antenna, checking the signal level at the TV, and going back to step 1 again and again until you're happy.
    – mrog
    Feb 28, 2018 at 22:22
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My grandfather solved this problem in his house many years ago (before digital TV, though he still has this setup for digital TV and it still works) using an Antenna Turner (sometimes called an Antenna Rotator) and a high-gain directional antenna.

You will need to get a map of the locations of the transmitters for the stations you are interested in and turn the antenna as you change channels. It's a little extra work, but it can make a very big difference.

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