Noise Filter (s)

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btritch

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I know it has been mentioned before....but I am going to bring it up once more, Does anyone have any recommendations on a filter to use on a scanner that is hooked to a scantenna to block out page and NOAA interference..? I'm getting NOAA interference BAD..Can't hardly hear anything else..Once in awhile there will be a page from an intercom come across..Does anyone have any recommendations on what kind to get? It will need to be for LMR 400 Cable with N connectors...I'm all ears, Suggestions? Anyone?
 

digitalanalog

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It has been stated the st2 (scantenna) tends to be directional.

If at all possible, try turning it,just look at it's facing direction and change it and see if that helps.

Sorry, not a filter solution, but this may help you.
 

K4DHR

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What are you trying to listen to?

Which scanner (if not all of them) is the interference the worst?

If you're trying to listen to local railroads, you're probably just SOL. Looking at the link provided, they have a 162 MHz filter, but it will attenuate railroad frequencies enough as to cause problems there too.
 

rankin39

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As suggested by Marauder6 the Par filters work well. Beyond that, it is often the case that NOAA or paging stations are not creating the interference by themselves. Frequently the problem is that those stations are MIXING with FM broadcast or TV stations that are also nearby and the interference is a *product* of that mixing. If you can discover which TV/FM station is mixing with NOAA/pagers, you can filter IT and get rid of your interference even more efficiently. When you hear the interference, listen carefully and see if you get any music or dialog from broadcasting in the background.

Bob, WoNXN
 

Bucko

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I have a pager on 152.480 with in a mile of me and it really does a job on most of my newer GRE scanners ( Unidens not so bad ). I bought a PAR http://www.universal-radio.com/catalog/filters/1813.html from Universal to see how it would do.It does block out the pager but also kills anything close to 152mz and there is some db loss with it in line. Like rankin39 said you need to narrow it down what is really messing up your scanners, the NOAA interference maybe caused by a pager. In my case it was pretty easy, I look out my window and see the tower for the pager.
 

zz0468

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You're asking for a lot to filter out both NOAA AND paging, since they're about ten MHz apart. You don't specify what frequencies you DO want. You could try a cavity notch filter of the NOAA frequencies and see how that behaves. They're big and expensive, but VERY effective in taking out a single offending signal. Available used on ebay for reasonable fees...

It's possible to use two to filter out the paging and the weather signals, but that can get quite complicated with critical length cables and requiring sweep tuning.
 

prcguy

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Yup, cavity notch filters will fix the problem and they can be cascaded and tuned to separate interfering frequencies. I once had a 250w UHF paging transmitter less than 5MHz away from my repeater input (on the same tower!) and a pair of these fixed the problem. Ebay is a a good source.
prcguy
zz0468 said:
You're asking for a lot to filter out both NOAA AND paging, since they're about ten MHz apart. You don't specify what frequencies you DO want. You could try a cavity notch filter of the NOAA frequencies and see how that behaves. They're big and expensive, but VERY effective in taking out a single offending signal. Available used on ebay for reasonable fees...

It's possible to use two to filter out the paging and the weather signals, but that can get quite complicated with critical length cables and requiring sweep tuning.
 
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