4G/LTE Interference

So far today, since 9 AM perfect reception without any interruption or pixelation. Five straight hours of excellent reception and it is very windy outside with trees swaying. CM LTE filter doing very well. Prior to installing the filter, there would be some type of interruption every 15 minutes to half an hour regularly.

I would swear that on some channels the SNR has even gone up ever so slightly. As if the adjacent interference in the past knocked the signal quality down a notch (weakened it) whether it knocked it out entirely or not.

Of course my LTE interference problem may be extreme in that I have two cell phone towers surrounding me - one to the left and one to the right - whichever way I drive out.

Possible pixelizarion…on some channels…Any Arizona…PhX…glendale area…chime in…Can’t get CBS 10-1 720 p , have to get SD 10-2.480p…?.. Did u suggest I install this on the antenna end before it goes into the 4 coax port CM 3414? We have 3 cell towers 1 mile in line sight of the 18 miles tv towers are.
So mine is …roof antenna…25 foot lead into attic where the 3414 is installed…so install before the RF into rf port on 3414 that feeds 4 rooms.

Or put in inline where the Tablo is on a splitter…tv and Tablo in one of those rooms…my office houses the Tablo

Here is a video where the guy shows three possible LTE filter installation points:

I installed mine right after the antenna and before the preamp.

Antenna (balun)–>LTE filter–>preamp—(coax cable 50’)—>distribution amp–>TV\Tablo

I installed mine before the preamp because I did not want the preamp amplifying the 4G signals. Others without a preamp or distribution amp install it right at the TV. In your case I would put it anywhere before the CM 3414.

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Perfect, I will install before the cm3414
Ordered today…$7.14 shipped :grin:

While watching TV direct from one of my distribution amplifier circuits (Tablo not involved) I noticed occasional screen streaks. The TV showed the signal at the time bouncing between 87 - 93 - 100 %. I suspected the 100 % might indicate an over-driven signal causing the pixilated streaks.

I had 10 db attenuators between by preamp and distribution amps so I added a 3 db attenuator in series and seemed to hit the “sweet” point as the disturbance went away.

One source of attenuators is here. If you bought the 10-pack at a discount to a single unit you can stack them for various attenuation levels.

Have fun!


In my case my signal can vary by as much as 6 db between seasons. In winter NBC comes across as 100% (30 db) but in summer can dip to 80% (24 db). I can sense that NBC sporadically overloads my tuners in winter because it rises above 30db for a few minutes then subsides.

Do your signals vary between seasons, and even if they do, you don’t have to remove the attenuator(s) when the signals fall?

I’m thinking I may need a variable attenuator to put inline just before my splitters in the basement such that I can walk downstairs and easily change the setting between winter and summer.

A variable attenuator sounds like a good idea. So far I have not needed to change my attenuator settings. They are used primarily to keep the antenna preamp from over-loading the distribution amps.

Two 8 circuit distribution amps? Are you supplying TV service to all the rooms at the Biltmore Estate?

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Although the distribution amps are 8-circuit, not all outputs are in use. Several circuits are capped off with 70 ohm terminators.

Let’s see what circuits were run.

Upstairs - 3 to bedrooms and 1 to living room.

Downstairs - 1 to Den; 1 to office; 1 to ham shack; 1 to garage; 1 to test bench.

Outside - 1 to hot tub location.

Total 10 circuits; all within reason and logic, I suggest.

I have been looking into this more, and here in Canada the government auctioned off the 700 MHz band for cell service not too long ago. So now OTA is only up to channel 51, so I would think the CM filter would be a better fit to only include up to 699 MHz.

The other filter up to 790 MHz would let in some interference.

BTW are you in Toronto? Does your Clearstream get both Buffalo and Toronto channels? Most people in that area have two antennas pointed in two directions (CN Tower and Buffalo).

Yes I’m in Torinto, the Clearstream 4V gets both the Toronto channels and Buffalo channels. The Toronto broadcast towers are underpowered in comparison to the Buffalo ones.

Can the LTE interference affect 5Ghz networks?

That’s not the end of the story. Consider the repack! The UHF band will end in three years time at channel 36 rather than 51. A new set of filters?

Probably a very elementary question, but is this interference likely to only affect one channel, or if this is the actual problem, does it tend to affect multiple channels? I have one and one only channel that provides pixelation from time to time and wondering if it is signal (i.e.; antenna pointing / obstruction) or interference?

It affects multiple channels. However if this is a UHF channel at a high frequency (channels 50 and upwards) close to the 800MHz band allocated to LTE it can be affected more than others. Especially if that signal is weak already…

One of the reasons for LTE interference is not only that it interferes with other frequencies, the strength of the LTE signal can overload a tuner.

Not for the moment UNTIL LTE expands to share the 5 Ghz band (as it has in Europe).

Still waiting on my $7.14 LTE filter. Low cost =long ship time…4 more days
I hope the low cost doesn’t mean low quality

Installed today…report back later

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From what you’ve heard/seen, are any channels being repacked from UHF to VHF-hi or VHF-lo frequencies?

Very few of what I’ve come across have switched to VHF (less than 2%). One station in Ohio will go lo-VHF but it is a minor station.

In my area 4 out of the 5 required to change will all stay UHF with one not reporting yet as to its intentions. And that 5th one has a free streaming app for all devices so that even if it went lo-VHF I wouldn’t bother getting a lo-VHF capable antenna.

My guess is that this 5th one is evaluating whether to even stay over the air or simply take the auction money and continue strictly as a streaming app. Their programming and audience is so specialized that it doesn’t matter to their viewers what medium they use to broadcast. Their audience will follow them. They also make past programs available via their website and Roku so one doesn’t need a PVR for them.