# HDTV with Antenna - lost some reception



## kdeerman (Jan 26, 2011)

I canceled my cable and installed a medium sized Directional UHF/VHF/FM Split Boom HDTV Antenna. I was getting all local channels, and some distant channels that were in & out. I wanted to get the distant channels also, so I bought a Channel Master CM-3418 8-Way Commercial Grade Distribution Amplifier. It worked well for a few months, then I began to lose the distant channels. I also lost two of my local channels that I should be getting, based on the direction my antenna is pointing. The LED is illuminated on the Amplifier, so it is getting power. Any suggestions?
Thanks


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## cwwozniak (Nov 29, 2005)

Hi and welcome to TSG.

If you are in the USA, you can visit the following web site to see if you have a suitable antenna and amplifier setup for your location. It will also provide aiming information.

http://www.antennaweb.org/aw/Address.aspx

You may be loosing signal strength due to weather conditions or possibly the TV stations tweaking their signal strength. It is also possible that strong winds may have changed your antenna's aim.


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## kdeerman (Jan 26, 2011)

Thanks, Chuck.
A friend at work had told me about that site and that's where I had gotten my information to begin with.
It told me a small multidirectional would get about 25% of the channels, a medium size multidirectional would get about 25% of the channels, a medium sized directional with pre-amp would get about 25% of the channels, and a large directional with pre-amp would get me the remaining 25% of the channels. It also told me the direction to point it, etc. 

I was also getting some channels farther away that were not on the list, that had older movies on during the week nights (ION). I liked that, but I lost that channel and a couple of local channels a few months later. What is a pre-amp? Is it different than the amplifier I have?

When you say weather, could it be better in the Summer than Winter, or are you referring to wind, rain, etc?

I have checked the direction and it is OK for now. I had been wondering if the TV stations were changing the way they broadcast. Why would they do this and what can I do if that is the problem?
Thanks


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## cwwozniak (Nov 29, 2005)

Let me start with the easy question; a pre-amp is a signal amplifier mounted right at the antenna and is powered by a power supply at the other end of the coaxial cable. The idea of putting an amplifier right at the antenna is to amplify a weak TV signal before it get even weaker (and noisier) traveling through a long length of coaxial cable.

Your question about weather only reminded me of how long it has been since I studied RF signal propagation is school. Heavy rain or fog may have some affect on signal strength but range issues may be more seasonal.

I found one web site run by a former TV station engineer that covers receiving HDTV signals over different distances and mentions atmospheric skip.
http://www.tvtower.com/hdtv_antenna_and_reception.html

I know that the site is not always noted for its accuracy, but I found some information on Wikipedia that discusses atmospheric affects on radio and TV signal distances.
http://en.wikipedia.org/wiki/TV_and_FM_DX


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## kdeerman (Jan 26, 2011)

Thanks!


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