Looking for a notch filter (Cell Phone Tower)

[InlandAZ]

Can anyone recommend a bypass filter (BNC) to filter out this tower near my home?

(Glennwilde) 19000 N Porter Rd (Lat: 33.051167 , Lon: -112.015889), Type: Pole, Structure height: 24.4 m, Call Sign: KNKN498, Licensee ID: L00128694, Assigned Frequencies: 880.020 MHz, 880.020 MHz, 880.020 MHz, 835.020 MHz, 835.020 MHz, 835.020 MHz, 891.510 MHz, 891.510 MHz, 891.510 MHz, 846.510 MHz, 846.510 MHz, 846.510 MHz, Grant Date: 09/08/2010, Expiration Date: 10/01/2020, Registrant: Gila River Cellular General Partnership

 

[Ubbe]

There are notch filters that can take out the whole 800-900MHz band but if there are some frequencies in there that you still would like to monitor, then it depends of what frequencies they are and how much loss you can accept. The best filters at 800MHz will probably take out everything +/-5MHz around the filters frequency but an be made to cover a wider range.

You can probably have one filter to attenuate 875-895 and another for 830-850 and leave the rest of the frequencies almost intact the further away you get from the filters frequency. 800-900MHz notch filters are something like $200 from PAR Electronics.

PAR Electronics | Filters for the commercial 2 way market, MATV, FM broadcast, laboratory, marine industry, amateur radio, scanner and short wave listening enthusiasts

PAR Electronics Inc. Filters for the commercial 2 way market, MATV, FM broadcast, laboratory, marine industry, amateur radio, scanner and short wave

www.parelectronics.com

/Ubbe

 

[InlandAZ]

I've contacted them - we'll see what they come back with.

Thx

 

[prcguy]

I believe all you have to worry about is the cell tower downlink frequency range of 869 to 896Mhz. 824 to 849Mhz should be the phone transmit side and nothing to worry about.

 

[Ubbe]

Isn't it all cellular above 900Mhz, so explain to Dale at PAR what the downlink frequencies are and what the highest frequencies you want to receive in that band are (867?) and he can give you the attenuation value for both the notch, or lowpass, and the bandpass frequencies and what the cost will be.

/Ubbe

 

[InlandAZ]

Talked with Dale yesterday, apparently he's out of service at the moment due to an accident. He's said he'd be back up and running next month, so I'll run all this by him then.

Thx guys -

 

[InlandAZ]

I'm fairly new to these Cell Tower issues - how does one calculate the downlink frequencies?

 

[Ubbe]

In the 800-900MHz band there are always a -45MHz difference to the uplink, what the mobiles transmit.
So your 880MHz are the downlink, what the tower transmit and 45MHz below that at 835MHz are the receive frequency of the tower.

/Ubbe

 

[slicerwizard]

Isn't it all cellular above 900Mhz

No. Where did that come from?

 

[InlandAZ]

Thx guys - you learn something new everyday.

 

[a417]

No. Where did that come from?

Sweeden uses primarily 900Mhz > for cellphones, maybe that's why?