Cell Tower Interference / SDR Trunk

maus92

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He only identified the band where it operates and basic parameters, not the specific system. LTE is spread spectrum technology, hence there is no one discrete / identifiable frequency causing the issue.
 

rabbit108

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He only identified the band where it operates and basic parameters, not the specific system. LTE is spread spectrum technology, hence there is no one discrete / identifiable frequency causing the issue.
OK, to be more precise: Dave is the only one that can provide that frequency or band of frequencies causing the issue. The answer to his problem is not going to fall in his lap; it is up to him to do the detective work and tests to discover the source. I can't do it for him, can you?
 

maus92

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Agreed, the OP needs to provide more info. Perhaps backing off on gain in steps might find a balance between a usable signal and distortion vs. the 700 band noise floor. Perhaps a directional antenna might help, or moving his current one. If it were me, I'd invest in a custom high-pass filter. Filters are not a bad thing as system operators use them to attenuate troublesome interference.
 

davejl2001

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I agree; you made it clear. Dave gave us his system parameters in his first post:

What is needed now is the freq of the transmitter causing the problem to specify the filter specs. Dave is the only one able to provide that missing information for HIS location.

OK, to be more precise: Dave is the only one that can provide that frequency or band of frequencies causing the issue. The answer to his problem is not going to fall in his lap; it is up to him to do the detective work and tests to discover the source. I can't do it for him, can you?
There is the frequency range. The site is about 8 miles away.

769.19375769.45625769.66875769.96875770.44375770.66875770.91875
773.34375773.79375c774.31875c774.54375c774.78125c
 

maus92

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The OP is avoiding IDing the actual system; I'm not sure why. Without the name / location of the system, it's more difficult to check the FCC licensing for the system for any applications to change its parameters wrt transmit sites, antenna orientation, power changes, etc.
 

rabbit108

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maus92

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Too bad it's a state license as it makes it more difficult to map potential changes without local knowledge - perhaps there is some relevant RPC correspondence. We'll have to assume the issue is interference from a new LTE site fairly close by, but not hideously close - I had a cell site 500' away that I could see out the window of my office but didn't suffer any ill effects (except possibly drowning out distant systems). Experiment with new antenna placement, a directional antenna, and / or buy a high pass filter. Or get a better receiver.

We had an issue with a Verizon LTE site (talk-out side) interfering with portables in a small town, with a secondary source from Axon body cameras (talk-in side). This will ultimately be resolved with a new system site in the area where the interference is being experienced. The FCC is aware of Band 13/14 LTE interference nationwide, but lots of finger-pointing going on. The carriers say their infrastructure sites are in spec and the system manufacturers need to design better radios, ignoring that their customers are not always using the best quality cell phones (or body cameras). We do need better receivers in general however.
 
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