I bought two antennas for over-the-air TV reception. They are the "Mohu Sky 60" and the "Channelmaster CM2020." I was wondering which is likely to get the strongest signal before amplification when the transmitters are about 35 miles away. I have the Mohu mounted at the peak of my roof, but some channels are still dropping out or pixelating severely - even with amplification. I have excellent signal strength but very poor signal quality. I'm wondering whether I will get a better signal if I mount the ChannelMaster in its place. I searched StackExchange sites and it looks like this is the most appropriate community where I could ask this question.
It depends on where the stations are located. The Channel Master has a lot more gain, and so will be much more directional. ie. You will have to point the antenna more directly at the station.
The same applies to the two antennas you have shown.
Update To address the comments:
An isotropic antenna is a theoretical antenna that radiates equally in all directions. ie. sphere.
A dipole is just two wires, one driven and one ground. Like this image from ARRL. And for reference back to the plot, the wires would be along the Y or vertical axis (from the markings -90 to 90).
Update 2 From Channelmaster, here is the pattern for the CM2020
Does the moHu have a built in amplifier? If so, that would skew the results.
If not, you would be better with the Channelmaster CM2020. Mount it outside, on a short mast. That should be sufficient for a 35 mile range to the transmitters.
I have something similar, only I need a pre-amp as I am close to 60 miles away from the stations. Here's a picture:
If you go to https://www.fcc.gov/media/engineering/dtvmaps and put in your address, it will tell what directions your stations are located relative to your house. If you click on the individual stations, it will give you an estimate of the signal strength. Note that the signal strength is in dBm, and is negative. That means a lower number (less negative) means a higher strength. This site will also give you a rough idea of the kind of antenna you need. If you're only 35 miles from the stations, the CM2020 seems to be overkill to me.
Excellent Signal Strength but poor signal quality
Sounds unlikely that this can be remedied with a better antenna. "High power but low quality" means that a signal that isn't your TV signal interferes and contributes power.
Unless, and that's the most likely explanation here, this quality/power measurement comes from consumer electronics device and doesn't actually mean much.
But let's assume these measurements are accurate and meaningful:
The TV bands belong to the TV stations, only. So:
- Any interferer that you can observe with your TV receiver is unlawful. Since fines are quite heavy, unlikely someone has a strong transmitter "for fun".
- Since your antenna currently is probably not pointed at anything but the direction of the TV transmitter, it is likely that the interference doesn't actually happen on any straight line from your antenna to the TV transmitter – there's typically mostly air and a few birds there, and neither is likely to be a strong emitter of electromagnetic waves in TV spectrum!
So, the most likely explanation (again, assuming that not just the power report of your TV is being bogus) is that there's some source of noise / interference in your installation. Make sure all your TV cabling has good connectors, is properly connected, not corroded. Make sure the power report goes to zero when you unplug your antenna cable.