Interference

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BIGTEXT

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Hello everyone I purchased this antenna hoping to improve my 800mhz reception 800/900 MHz 6 dBi Omnidirectional Antenna - HGV-906U

Unfortunately I live right under the county's 800mhz tower and I have numerous cell and pager sites within less then a mile. So now I have to use global attenuation which is leading to a result that's actually worse than just using the radio shack 800mhz antenna.

Is there some sort of filter I can put on the line to get some of the pager sites and crap out of there? I was looking on scanner masters website but I dont quite know what I would need to buy or if anything would even help.

Scanning on a PSR-500. Line from antenna to scanner is LMR-400.

Any help would be appreciated!
 

jackj

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Unfortunately I don't think there is much you can do to reduce your interference. Most of your interference will be coming from your county's 800 MHz site. I assume it's a trunked system so it will have at least one transmitter on 24/7 and that transmitter is overloading your scanner. Any filter that would take out your county's system will also take out most of the rest of the 800 MHz band.
 

BIGTEXT

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Well that's too bad. I spent a lot of time fishing that dang cable down through the wall.
 

DickH

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Hello everyone I purchased this antenna hoping to improve my 800mhz reception 800/900 MHz 6 dBi Omnidirectional Antenna - HGV-906U

Unfortunately I live right under the county's 800mhz tower and I have numerous cell and pager sites within less then a mile. So now I have to use global attenuation which is leading to a result that's actually worse than just using the radio shack 800mhz antenna.

Is there some sort of filter I can put on the line to get some of the pager sites and crap out of there? I was looking on scanner masters website but I dont quite know what I would need to buy or if anything would even help.

Scanning on a PSR-500. Line from antenna to scanner is LMR-400.

Any help would be appreciated!
Did you try it without any antenna connected?
 

zz0468

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Without a spectrum analyzer, it's going to be very difficult to determine exactly what signals are driving your radio into overload. If they're 800 MHz signals, and that's what you're trying to listen to, no filtering will fix that. If it's 880 MHz cellular, or even further out of band, you could get a filter that allows only 850-870 to pass, at the expense of everything else. But if it's signals within the 850-870 MHz range causing the problem, the fix is attenuation, or maybe a different antenna. 6db is an awful lot of gain to hear a site 1 mile away.

Global attenuation applies 20db of attenuation. It's possible that a lesser amount of attenuation will be sufficient for the radio to work ok, but the only way to do that is do it externally. You can get 6 and 10 db attenuators on eBay for fairly cheap. It might be cheaper and easier to try that before you spend a couple hundred dollars on a custom built filter.
 

BIGTEXT

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Thanks everyone.

I didn't get the antenna to hear the local county site. I was hoping to pull in more distant sites. I can hear the local site just fine without any antenna at all and attenuation on, I am literally under the tower.

I imagine most of the interference is coming from the local tower and I guess I was just silly for not thinking about it before I bought the new antenna. Guess all I can do now is move haha.
 

wmbio

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GRE/Radio shack scanners are prone to easy front end overload across the entire spectrum...Sad! This is a cheap fix and has worked for many users here at RR....try it first.
A $3.00 FM filter from MCM to reduce intermod, the same filter can be found at Radio Shack.
...works great....FM Trap | FM-88 (FM88) | Distributed By MCM

Enjoy
Wmbio
 

zz0468

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...This is a cheap fix and has worked for many users here at RR....try it first...
That's only a cheap fix if it's an FM broadcast station causing the problem. Otherwise, it's a waste of money. In solving an interference problem, it's essential to have an understanding as to exactly what the problem is.
 
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