Channel Master LTE Filter

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737mech

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So I just saw this available. https://www.amazon.com/Channel-Mast...TF8&qid=1541032658&sr=8-3&keywords=lte+filter Since I like my 800 trunking systems I'm not likely to add this to my scanner setup. Brings in the question does LTE create problems for scanners? I have not noticed any issues above 700 causing intermod on my setup. Maybe there's something to be learned here? Seems channel master wants people to use this with ota TV antenna setups especially if using amps. Now I'm gonna have to check my local OTA TV channel freqs list to determine if I have issues in those bands or not?
 

Ubbe

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TV boxes and receivers inside a TV uses cheap SDR chips that easily gets overloaded and have images when receiving strong signals. The normal TV user just installs an amplifier with 20dB gain without considering the overload issue or checking if it was too much signal that caused the bad reception. So that's one reason for selling LTE filters and that some antennas have mechanical traps for LTE frequencies to help the non-technical home owner.

If you have a receiver based on a cheap SDR chip you'll have to remember to not expose it to strong signals. LTE uses frequencies in the 700,800 and 850MHz blocks so it will be pretty much impossible to filter them out without spending a fortune.

/Ubbe
 

mmckenna

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We had a site here at work with about 20 Iridium modems pulling research data off the satellites. It was on a building roof top adjacent to one of my towers.
On that tower was 2 100 watt VHF repeaters, an 800MHz repeater and all 4 major cell carriers (lower power DAS system).
I also had a 1090MHz ADS-B receiver up there.

It all worked fine.

Until Verizon showed up and swapped in the 700MHz LTE stuff.

Then the ADS-B radio and all the Iridium modems went deaf. I tried a filter on the ADS-B box, no luck. We tried swapping out the LMR-400 on the Iridium system to 1/2" heliax, no luck.

Verizon played around with filters, adjusting power levels, antenna down tilt, etc.

Finally we ended up just moving the Iridium gear to another location and I relocated my ADS-B radio.
 

iMONITOR

Silent Key
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S.E. Michigan
Question:
What is the cutoff frequency/band? 51?


Answer:
Frequencies passed are between 5 - 699 MHz


Tom G
· September 29, 2018 I have no idea, I would look on their web site. They have a lot of information there.


M. K. Probst
· September 29, 2018
It blocks 700mhz and higher.... for antenna channels this is OK, for cable, reference their technical charts for channel frequencies....



 

crucialcolin

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Yeah I don't think it would be a good idea if you want to monitor 800 mhz systems. I wouldn't be surprised that LTE itself causes problems with scanning. That is being near any sort of cell tower.

In fact, I have recently discovered that there are two 1000w pager systems on 930 mhz located within my city(Roseville) in the Union Pacific rail yard. I suspect it is severely impacting my ability to receive the neighboring(Sacramento) county's 800 mhz trunking system even though its closest broadcast site is located within 7 miles from my house.

I have noticed with a little testing going mobile with a Larsen NMO tri-band once I get to the other side of that com tower and away from the yard reception improves dramatically. *edit of course by then your pretty much on the border of Sacramento County anyways..
 
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