5g interference?

wagonman76

SatelliteGuys Pro
Original poster
Nov 11, 2006
164
110
Northwest Lower Michigan
I'm wondering if I am getting 5g interference. Over about the last month I am getting a lot of pixellation, and now it's even on very strong channels like NASA with 99% quality. It is the same anywhere on the arc (87W near the zenith to 133W). Severity varies here and there, but every week it gets worse overall. Only on C band, Ku is perfect.

Here's what I have done, with no change:
Peaked skew, dish position, checked dish adjustment.
Swapped cables to dish, other cables, voltage block couplers, LNB voltage outputs.
Swapped LNBs. (I have a spare identical LNB and I know they both work.)
Bypassed splitters and Diseqc switch.
It's not windy and the snow is gone. No storms rolling through. Nothing clogging the feedhorn.

I looked up 5G coverage in my area, and the only one listed is T Mobile. They have a prominent tower 5 miles up the road, but over hills and through woods. I live in the sticks on a 9 acre plot, where even ATT 4G LTE requires an antenna on my house. Also according to the link below, T Mobile 5G runs at 2.5 GHZ. And the tower is due north of me, my dish points south.


So say that the other competition (ATT and Verizon) have put in 5G somewhere, according to the link they run at 3.7 GHZ. Both my LNBs are Echostar 0950, which run at 3.7-4.2 GHZ. So I'm not convinced that these budget LNBs I see that say 5G rated, and run at 3.7 to 4.2, will be any better.

I looked at all the channels I watch, and none are lower than 3.9 GHZ. I don't want an LNBF, I want to keep my setup that has C and Ku in the same feedhorn. So I am thinking the best thing would be a Norsat BPF-5 inline filter or LNB.

Very pricey. I don't mind so much if it's a one time purchase that will solve the problem and last awhile. But I would hate to spend the money only to find that the problem still exists. Is there any way to really determine that 5G is causing the issue? Or any other ideas?
 
3.7 - 4.2GHZ bandpass LNB or LNBF models are not suitable to filter adjacent freq interference in North America, where the licensed 5G bands are within the bandpass of frequency range. 3.7 - 4.2GHz bandpass LNBFs are sold to address the licensed bands in use in their region. When 5G 3.7GHz use was announced for NA, our previous filtering LNBF models were tested to be ineffective and we discontinued them. Read the product description and understand that just because the product title indicates 5G filtering, it may not be the appropriate bandpass range for the frequencies in use within your region.

Many LNBs and LNBFs are wideband 3.4 - 4.2 with minimal out of band filtering. In the past, i had serviced and tested units and found that were manufactured wideband and simply labeled with a bandpass range suitable for the distribution market. I have also fouund many LNB(f) to be labled 3.7 - 4.2GHz, but had no or minimal bandpass filtering. They rejected by component tuning performance. The further off center frequency, the lower the performance and the resulting increased attenuation.

If you indeed are experiencing interference from 5G (am almost certain by your description), start by using a LNB, LNBF or waveguide filter with 3800 - 4200MHz bandpass ( we offer the C138 and C238 LNBF models). If the source of interferening signal(s) is too strong, the dish may need to be shielded. Some will relocate the dish behind a structure or build an "RF fence" to block the terrestial interference.

You don't need a fancy sprectum analyzer to identify local interference frequencies, sources and direction. The TinySA is available on Amazon, Ebay, etc for $50 - $75. Connect to a wideband LNB / LNBF using a port blocking 3ghz splitter or use a directional resonant antenna to identify carriers on adjacent frequencies.

Some just throw money at the wall to see if it sticks... LOL. For many, a $70 purchase of a C-138 LNBF is an inexpensive test that they usually will find to solve their 5G interference issue.

Waveguide filtering is the best option if you wish to retain C/KU on a single feedhorn. Personally, I would run a LNBF sidecar a KU LNBF or a better option is to run a separate KU dish. But, it is personal preference and the size of the expediture in one's hobby.
 
You don't need a fancy sprectum analyzer to identify local interference frequencies, sources and direction. The TinySA is available on Amazon, Ebay, etc for $50 - $75. Connect to a wideband LNB / LNBF using a port blocking 3ghz splitter or use a directional resonant antenna to identify carriers on adjacent frequencies.
Hi Brian

My understanding is that the TinySA works up to 960 Mhz. Is there a way to make it work with the usual L-Band range used by satellite equipment?

Thanks

Bruno
 
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You are right. I was thinking of the frequency range on the nanoVNA. Rarely use the tinySA above 70cm. I was using the Dr.HD 500Combo BT unit the other day. A really cool device for tracking signals.

This SA unit looks promising for direct RF and IF sampling. Haven't tried it yet, but might upgrade from the tinySA.
Amazon product ASIN B097R5QBPWView: https://www.amazon.com/Portable-Spectrum-Analyzer-Frequency-35MHz-4400MHz/dp/B097R5QBPW
not deal bad at $180.

35MHz-4400MHz Handheld Spectrum Analyzer 4.3" LCD Display Aluminum Housing | eBay or $105 Ebay from China

www.aliexpress.com/item/1005003873345423.html $75 on Aliexpress
 
Good call. I was wondering that myself. I thought perhaps the lnb and splitter had something to do with outputting a different frequency that the tinysa could recognize.

I didn’t buy anything yet. Been scouting my area and there’s only one power pole in view from the dish, and it’s got a bunch of stuff on it. Everything else is blocked by trees or the house. Dish photo is from the pole area last fall. It’s been cold and crappy lately, but when it gets a little nicer and the ground firms up I’m gonna pull my metal sided travel trailer around to see if blocking the view of that pole helps at all. Maybe prop up a sheet of metal roofing too. The black canister and all went in when they ran fiber internet a couple years ago. The fiber is in tandem with the electric company and it helps them determine outages, also got internet to tons of us who the local cable monopoly would never service. Who knows maybe the electric company changed or strengthened their frequency.

A dedicated Ku dish might be an option. The dish is about 120 feet from the house with the wires buried in conduit so I don’t want to run new wire, but the existing wire might do it.
 

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You are right. I was thinking of the frequency range on the nanoVNA. Rarely use the tinySA above 70cm. I was using the Dr.HD 500Combo BT unit the other day. A really cool device for tracking signals.

This SA unit looks promising for direct RF and IF sampling. Haven't tried it yet, but might upgrade from the tinySA.
Amazon product ASIN B097R5QBPWView: https://www.amazon.com/Portable-Spectrum-Analyzer-Frequency-35MHz-4400MHz/dp/B097R5QBPW
not deal bad at $180.

35MHz-4400MHz Handheld Spectrum Analyzer 4.3" LCD Display Aluminum Housing | eBay or $105 Ebay from China

www.aliexpress.com/item/1005003873345423.html $75 on Aliexpress
Hi Brian,

That does sound appealing!

Also, can the nanoVNA be used effectively as a spectrum analyzer? I'm not sure what vector network analyzer really means

Thanks
 
No, a VNA is not a spectrum analyzer. A VNA is used to test components and system performance using a signal generator with defined parameters. Examples how I use a VNA is to test or tune an antenna for resonance, a feedline's efficiency or faults, and for tuning a duplexer.

With the low cost and availability of the nanoVNA, there are a ton of Youtube videos on basic calibration and applications.
 
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I could be wrong but that round thing down on the power pole in the first photo looks like a 5G repeater.
The lower can and loops of extra wire are for the fiber they put in 2 years ago. The fiber runs overhead and the extra is wrapped up in case repair is needed. Though it’s possible they could have transmitters in them. The fiber company doesn’t offer wireless, at least for consumers.

What I’m curious about is the black stair step looking box opposite the lower can. Wondering if that might be a T Mobile repeater. There’s a red tag on it but unfortunately it was sitting just right where I couldn’t get a view of it. There are some other poles down the road with the same thing, maybe I can get a view of one of those.
 
Been thinking a lot about which way to go.

Waveguide filter would be easiest, but if frequency cutoff needs to change later, I'll have to buy another one tuned for that.

I decided to order a C138 from Titanium for starters. Will be a good diagnostic tool at minimum.

If that solves the issue, then I think I'm going to sidecar a Ku LNBF. It was always a mystery to me how that could even work, since Ku is even more finicky than C for being on center. This thread I found really explained it well, and now I understand it enough to give it a shot. I could mount it on the west side of the feed, since there isn't really any Ku past 125 W anyway (that I know of) and I can still go to where the Alaska channels used to be at 139W. The offset is 10 degrees in the thread so with a similar mount I should be within range.

 
TLDR: Looking for a new FTA receiver with RCA outputs.

Well considering I got a mandatory week off due to Covid and I've been feeling mostly better the last couple days, I've had time to tinker with the dish.

I got my LNBF from Titanium yesterday. To remove my existing scalar would be a large undertaking. It was so close so I just sanded the paint off the LNBF tube to fit into my scalar. Vertical came in great, but horizontal would not scan. I made sure everything was spot on. So to rule out dish alignment, I remounted it 90 degrees out. Vertical (horizontal channels) now came in great, and vice versa. I checked the voltage coming from the Geosat both ways and it was good.

I checked for voltage drop in all places, splitters, connectors, cables. Turns out the Geosat puts out the correct voltage, but not enough oomph. To run the 13/18v switch, the 18v drops enough to not even solidly run the switch, and that's where my pixellation was coming from. To bypass the switch and directly run the LNBF, it drops to like 16 or so. Enough for the LNBF to know it's not for the vertical, but not enough to actually run the horizontal. The 13v barely drops so vertical isn't affected.

I tried running the horizontal alone, while bridging power from my GI receiver, and that made the horizontal run great. Unfortunately I don't have a 13V output on it, both the C and Ku are 18V. That's my normal setup, the FTA has all the C on H, and all the Ku on V. The 13/18V output switches the direction of the signal path. Each way has a voltage block coupler after the switch, then out to the LNB thru a splitter that draws the needed 18V from the GI receiver. The GI box also changes the polarity with the servo motor. The LNBF is nice in a way, not having to mess with polarity, but I lose the ability to tweak the skew from my living room, that's come in handy many times.

I grabbed this Freesat V7 Max from the basement, that I had bought years ago as a spare. It controls the LNBF great. I really like the interface, but it does have some glitches, like initial startup on PAL, and some satellites it will hang so you can't get the channels. Like NASA and FOX. :( But I did get some channels I had been unable to get for a long time, like Decades. Must just have been the low voltage issue.

Today I decided to try it with the original feedhorn assembly. Sure enough, the original works great now. No interference. So I must not have 5G out here, or enough to make a difference. And if I do get it, the LNBF will come in handy for testing and all.

The Geosat has been running on fumes for a long time. First it wouldn't hold memory if the power went out, solved with the UPS I bought when I got internet out here. Then the L/R sound outputs went out so I use the coaxial with a converter. Now it's the 18V output going weak.

So it looks like I am looking for a new FTA receiver with RCA outputs. Since I love my vintage big screen 4:3 TV and all. I hear good things about the Mio. Which I would get if there's a proper HDMI converter, but everything I've read about is hit and miss. I also don't want everything to have black bars and burn in my screen. Right now most things show in 4:3. I actually quite like the Geosat. Or even the Freesat if the scanning bugs were fixed. Anything better out there?
 
TLDR: Looking for a new FTA receiver with RCA outputs.

Well considering I got a mandatory week off due to Covid and I've been feeling mostly better the last couple days, I've had time to tinker with the dish.

I got my LNBF from Titanium yesterday. To remove my existing scalar would be a large undertaking. It was so close so I just sanded the paint off the LNBF tube to fit into my scalar. Vertical came in great, but horizontal would not scan. I made sure everything was spot on. So to rule out dish alignment, I remounted it 90 degrees out. Vertical (horizontal channels) now came in great, and vice versa. I checked the voltage coming from the Geosat both ways and it was good.

I checked for voltage drop in all places, splitters, connectors, cables. Turns out the Geosat puts out the correct voltage, but not enough oomph. To run the 13/18v switch, the 18v drops enough to not even solidly run the switch, and that's where my pixellation was coming from. To bypass the switch and directly run the LNBF, it drops to like 16 or so. Enough for the LNBF to know it's not for the vertical, but not enough to actually run the horizontal. The 13v barely drops so vertical isn't affected.

I tried running the horizontal alone, while bridging power from my GI receiver, and that made the horizontal run great. Unfortunately I don't have a 13V output on it, both the C and Ku are 18V. That's my normal setup, the FTA has all the C on H, and all the Ku on V. The 13/18V output switches the direction of the signal path. Each way has a voltage block coupler after the switch, then out to the LNB thru a splitter that draws the needed 18V from the GI receiver. The GI box also changes the polarity with the servo motor. The LNBF is nice in a way, not having to mess with polarity, but I lose the ability to tweak the skew from my living room, that's come in handy many times.

I grabbed this Freesat V7 Max from the basement, that I had bought years ago as a spare. It controls the LNBF great. I really like the interface, but it does have some glitches, like initial startup on PAL, and some satellites it will hang so you can't get the channels. Like NASA and FOX. :( But I did get some channels I had been unable to get for a long time, like Decades. Must just have been the low voltage issue.

Today I decided to try it with the original feedhorn assembly. Sure enough, the original works great now. No interference. So I must not have 5G out here, or enough to make a difference. And if I do get it, the LNBF will come in handy for testing and all.

The Geosat has been running on fumes for a long time. First it wouldn't hold memory if the power went out, solved with the UPS I bought when I got internet out here. Then the L/R sound outputs went out so I use the coaxial with a converter. Now it's the 18V output going weak.

So it looks like I am looking for a new FTA receiver with RCA outputs. Since I love my vintage big screen 4:3 TV and all. I hear good things about the Mio. Which I would get if there's a proper HDMI converter, but everything I've read about is hit and miss. I also don't want everything to have black bars and burn in my screen. Right now most things show in 4:3. I actually quite like the Geosat. Or even the Freesat if the scanning bugs were fixed. Anything better out there?
When you blind scan with the V7,don't scan for "radio" channels.Those sats with the hundreds of radio channels will lock it up every time.
 
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Well after a lot of reading here and other places, I pulled the trigger on a Amiko Mini HD 265 from KE4EST. Sounds like a solid reliable unit that's had plenty of time in the hands of users, and has RCA outputs.

I read the 75 page thread on the Geosat Pro HDVR3500, and I'm surprised mine has lasted this long. Been using it since early 2017.
 
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Going back on topic, I am no longer able to receive lock on anything below 3785MHz and the dish is heavily shielded on 2 sides. For now, I'm not planning any further changes as there isn't much below 3800MHz and everything else seems unaffected thus far.
 
I could be wrong but that round thing down on the power pole in the first photo looks like a 5G repeater.
It's actually a fiber drop. My rural electric just finalized their construction. The old ISP infrastructure using hardline is actually leasing their fiber here. Rather than running new coax through the sticks.
BTW. Does anyone have a video they could post using an SDR to sweep the I.F. spectrum of their unfiltered LNBF?
That's my next project. Since I have no 5G interference here (as of yet) it would be interesting to see an A/B comparison.
Also. It appears that the issue is for the guys with fixed dishes.
Would that mean that if you experience 5G interference on one sat, that you would or could you get the same thing looking at sats in other sections of the arc for ones with a movable dish?
 

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