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pkrawetz

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So I have been having issues with receiving the CT State Police in Mystic, CT. Seems my BCD996P2 cannot lock in and keep the control channel. Thought maybe I'm too close to the cell tower about 200 yards from us. So I bought a BPF-800-EN band pass filter for 765-861MHz. Well low and behold that fixed my problem. But now I don't hear anything on the other frequencies I have programmed in the scanner.

I have tried to move the scanner to different location (no filter installed) without success so I'm guessing it's the radio tower causing the issues.

I want to be able to hear everything I have programmed. Is there such thing as a wide band filter to allow full range scanning but eliminate the issue I've discovered?
 

Whiskey3JMC

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So I have been having issues with receiving the CT State Police in Mystic, CT. Seems my BCD996P2 cannot lock in and keep the control channel.
Have a read here about simulcast distortion. It's one of the most discussed topics/issues on these forums. It can really cause problems when monitoring a simulcast system on anything other than a Uniden SDSx00. CLMRN contains simulcast cells so it all depends on your location relative to two or more towers. The Uniden SDS series scanners were designed to combat the effects of simulcast distortion & I was able to successfully monitor the CLMRN from my SDS100 when passing through CT last week. There are a number of workarounds mentioned in the wiki I linked but they work for some & not others.
 

pkrawetz

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Have a read here about simulcast distortion. It's one of the most discussed topics/issues on these forums. It can really cause problems when monitoring a simulcast system on anything other than a Uniden SDSx00. CLMRN contains simulcast cells so it all depends on your location relative to two or more towers. The Uniden SDS series scanners were designed to combat the effects of simulcast distortion & I was able to successfully monitor the CLMRN from my SDS100 when passing through CT last week. There are a number of workarounds mentioned in the wiki I linked but they work for some & not others.

Thanks for the info. I already tried some of the suggestions in the wiki article (simulcast distortion) and I've pretty much done all of that. Frankly having to buy a more expensive scanner to resolve this issue seems a little much but I guess I might not have a choice. :(
 

Ubbe

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Thought maybe I'm too close to the cell tower about 200 yards from us. So I bought a BPF-800-EN band pass filter for 765-861MHz. Well low and behold that fixed my problem. But now I don't hear anything on the other frequencies I have programmed in the scanner.
Seems like it has to be those cellular frequencies swamping the scanners input. Try getting a band stop or notch filter for the cellular frequencies that will still pass all other frequencies.

/Ubbe
 

WA0CBW

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Like ubbe said sounds like the cell tower is overloading your scanner. You may still have simulcast issues after filtering out the cell tower frequencies.
BB
 

vagrant

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It appears that BPF-800-EN filter is “passing” 765-861 fine and blocking everything else, as it should. If you are receiving 765-861 MHz and not much else, then you caused your new issue of not receiving other frequencies outside of that range.

Perhaps a notch filter specific to the nearby cell tower freq, or a low pass filter which allows signals to come through below a particular freq, or a combination of the two. If the offending cell signal is around 860-870 MHz, a low pass filter that tops out at 860 should help and will pass frequencies below that. What frequency range does the cell tower use?
 

iMONITOR

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Have a read here about simulcast distortion. It's one of the most discussed topics/issues on these forums. It can really cause problems when monitoring a simulcast system on anything other than a Uniden SDSx00. CLMRN contains simulcast cells so it all depends on your location relative to two or more towers. The Uniden SDS series scanners were designed to combat the effects of simulcast distortion & I was able to successfully monitor the CLMRN from my SDS100 when passing through CT last week. There are a number of workarounds mentioned in the wiki I linked but they work for some & not others.

That's not the problem he's having. He's receiving his public safety system just fine after adding the band pass filter. The filter is doing exactly what it's supposed to do, pass the band he was concerned with and block everything else.

Ubbe and vagrant are exactly right!
 

popnokick

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You may be "too close" to another type of tower: commercial FM broadcast. FM broadcast radio either by itself (88-108 mHz) or as a "mixing product" with another non-FM broadcast transmitter (e.g. paging, public safety, LMR, etc.)... can play hob with scanners and other receivers. Before you spend the big $$$ on a new scanner, remove the filter you just installed and try an FM broadcast filter instead. PAR and others have them... lots of threads here on RR about the damaging effects of FM broadcast interference. An FM filter costs very little to try.
 

pkrawetz

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Seems like it has to be those cellular frequencies swamping the scanners input. Try getting a band stop or notch filter for the cellular frequencies that will still pass all other frequencies.

/Ubbe
Do you have any specific ones with a URL link?
 

Whiskey3JMC

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That's not the problem he's having. He's receiving his public safety system just fine after adding the band pass filter.
Regardless if it's the problem the OP is having or not, an SDSx00 should receive the system without adding any additional hardware. I work right next to a cell tower and can pick up my county's simulcast system without a hitch on my 100
 

pkrawetz

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Regardless if it's the problem the OP is having or not, an SDSx00 should receive the system without adding any additional hardware. I work right next to a cell tower and can pick up my county's simulcast system without a hitch on my 100

LOL I just ordered an SDS200. Pricey but lets see how it works.

Thanks for all who replied. Anxiously awaiting my new scanner.
 

KevinC

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Regardless if it's the problem the OP is having or not, an SDSx00 should receive the system without adding any additional hardware. I work right next to a cell tower and can pick up my county's simulcast system without a hitch on my 100

Maybe the OP is in the Fresnel zone of one sectors antennas, maybe they are different bands than the tower by you, maybe they have higher gain antennas, maybe they have a different beamwidth, maybe they have more or less downtilt, maybe the OP has less trunked system signal strength than you do. Lots of different factors involved besides just being close to a cell site.
 

pkrawetz

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Maybe the OP is in the Fresnel zone of one sectors antennas, maybe they are different bands than the tower by you, maybe they have higher gain antennas, maybe they have a different beamwidth, maybe they have more or less downtilt, maybe the OP has less trunked system signal strength than you do. Lots of different factors involved besides just being close to a cell site.

Lots of maybe's but I can say when I put in the BPF-800-EN filter, all of my CT State Police systems are now working perfectly and clear voice communications. It filters out other bands which is what I don't want as I can no longer listen to them. I count 3 different cell systems on the water tower as well as a microwave link dish so there is a lot of power coming out of that tower.
 

popnokick

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When all else fails... or "can't be" the root cause.... throw $$$ at the problem! Congrats on your new radio, and I sincerely hope the problem never recurs.....
 

Ubbe

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... try an FM broadcast filter instead.
The scanners own filter for 700-1300MHz will probably attenuate 100MHz much more than any FM trap filter. There are passive band pass filters in scanners before any active devices that can be overloaded.
Do you have any specific ones with a URL link?
You could try something like a $35 BLP-550+ filter from MiniCircuits that will be fine if connected in parallell with your current filter, if you do not have anything to receive above 860MHz.

/Ubbe
 

pkrawetz

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Hey all thought I would let you know I received my SDS200 scanner and it works perfectly, no filter installed. So it appears the BCP996P2 has older technology and is subject to interference. Very happy with the SDS200 except for the programming aspect. What a PITA!
 

pkrawetz

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Hey all thought I would let you know I received my SDS200 scanner and it works perfectly, no filter installed. So it appears the BCP996P2 has older technology and is subject to interference. Very happy with the SDS200 except for the programming aspect. What a PITA!

As a side note I'm now back in GA where I was having an aweful time hearing the digital trunked system for my county. It's now loud and clear with the SDS200. Spent 5 years trying to the get the BCD996P2 working by moving it around, trying different antennas, etc. Nothing was a permanent fix. Well worth the money spent on the SDS200.
 
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