Is it possible to block/shield an antenna?

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Bonzai

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I am currently trying to scan the Minnesota ARMER P25 simulcast in Ramsey county using a Uniden BCD996XT. I live between two towers and receive full bar reception, however the audio is choppy due to receiving the same frequency from both towers. My question is can I block/shield the antenna on one side to block or reduce the signal from one of the towers, or am I going to have to invest in a Yagi antenna? If blocking/shielding is an option, what would be the best way to achieve this?

Thanks in advance for any help.
Bonzai
 

jerk

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I am currently trying to scan the Minnesota ARMER P25 simulcast in Ramsey county using a Uniden BCD996XT. I live between two towers and receive full bar reception, however the audio is choppy due to receiving the same frequency from both towers. My question is can I block/shield the antenna on one side to block or reduce the signal from one of the towers, or am I going to have to invest in a Yagi antenna? If blocking/shielding is an option, what would be the best way to achieve this?

Thanks in advance for any help.
Bonzai
Foil is simplest and cheapest; tree leaves also really attenuate 800 MHz too.
Sometimes a simple location change high/low one end of the house to the other works wonders as well. But foil or some type of metal, computers also work well for blocking, but create their own noise issues. I have asbestos tiles on the house, those block signals as well.

The thing is to experiment.
 

zz0468

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...or am I going to have to invest in a Yagi antenna? If blocking/shielding is an option, what would be the best way to achieve this?
Invest in a directional antenna, or find the plans to build one. Then, when you do, start by aiming toward the desired transmitter, but be aware, if you're trying to block a specific transmitter, best reception may come by aiming someplace else determined by trial and error.
 

jackj

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In a well designed system, adjacent towers won't use the same frequencies. If you are sure this is your problem then zz0468 is right, you should use a directional antenna. Trying to shield an omni directional antenna from signals in only one direction is difficult at best.
 

ERICMYERS

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for sure, NJjay - that's a pain in the neck around here.

OP - a little time researching, $15 in materials, simple tools and a couple hours work you can build a fine Yagi with stuff you can get at the local hardware store. That's what I did to handle multipath issues. It absolutely worked, when absolutely nothing else would, not for the lack of creativity and trying (which other than for the learning what doesn't work was a total waste of time).
 

Bonzai

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Thanks for the responses everyone. I think I will do some more research and try to make something myself. Any advice or links that may help would be appreciated.



Thanks again,
Bonzai
 

zz0468

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Build yourself a corner reflector antenna, much better F/B ratio than a Yagi.

Very true, and a cleaner pattern. Sometimes, though, the nulls between lobes on a yagi can be used to advantage to keep a specific site from being a problem.
 

n5ims

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Since you have full bar receiption, try to reduce the signal strength to see if that helps. My area also uses a simulcast system and often the receiption improves simply by grabbing my portable's antenna to reduce the signal strength. If you use an outside antenna, you may try using an antenna from a portable (if one's available) to see if that helps. The GRE scanners have a built-in attenuator to help with this issue.
 
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