How To Look For & Find 5G Interference in C Band

[ArloG]

Vu+ produced great subscription boxes. Vu+ satellite receivers do not perform exceptionally well as a fta receiver. But if you think they are that great, then buy one or two. Also, the pluggable tuner thingy is Wonderful! That is until you turn on the receiver and find the tuner is not recognized. Then the pluggable tuners are not Wonderful anymore. But again, buy one and see for yourself. Great subscription box!

Oh hell! Not exactly the point I was getting at. Actually as you know. I was pondering of grabbing one from a dude on linuxsat who offered to get one (he's an admin there) and ship to me as a gift to give it a whirl over here. Because he's friends with World of Satellite I was given the option to test it for an extended period after the return policy. Pretty cool, huh? Of course I'd pay him for it. The bottleneck was what tuner or tuners to pick that would work here. As for not recognized (tuners). I didn't tear the latest TNAP down to see how many tuner drivers you include. I would suspect only the custom AVL drivers for the mio(s). Makes sense. Adding drivers for let's say and external USB tuner shouldn't be difficult...not saying dealing with anything Linux is ever easy. Lol!!
I'd have to say since he's getting more FTA channels and getting them better with more signal strength where the mio craps out or is blind. He made his point.

Pluggable tuners a "thingy"? Kinda like saying a dish with a welded on lna/lnbf would not be a "thingy" don't you think? I ain't going to run out and buy a VU+ or any other new receiver unless it's a TBS card anytime soon.

I want to put something into perspective. I've been into amateur radio since like forever. My dad and I had out tickets when I turned 10. And 10 was a long time ago.
Anyhow. Some years ago I purchased an unblocked Icom IC-R8500. Enjoyed it for years besides my stack of boat anchor radios. Love the smell of coffee and tubes in the morning.
A few years back I purchased an IC-R8600. And the stock brick power supply. It didn't take long to find it just didn't have the sensitivity in HF/VHF that the 8500 had. Unbelievable, right!
Antennas...check, cables.....check, all that. Being new and under warranty I didn't even screw with it. I boxed it up and sent it to Michigan to Icom's service center.
Got it back in flying colors. It met and exceeded factory specs. With a printout of actual test results. So. What's the deal? Sensitivity sucked still compared to other radios.
Crap. The switching power supply was the culprit. I sent it in too at the time. My R8500 had a linear power supply. No noise, no hash. The R8600 with a linear or battery is simply amazing now.

So. Back to your VU+ thingy. A guy with one satellite receiver. The mio because it was the cat's ass and everyone said to grab it. Or the dude who gets a zap that kills the tuner rendering the receiver a boat anchor. Kind of makes it an Apple Mac that borks a graphics card or whatever on a Friday. Not an easy thing to blast to the pc store and grab any old GPU and slap it in and you're golden.
The dude that proved his receiver got things that the mio didn't by a heavy margin. And proved it, made a very good point. Dontcha' think?
Yeah. I kinda' repeated myself. In case the mio ears didn't grab it on the first scan.
It's cool. Smack that kiss my ass button. I'm a good humored person. If you're a brit you can add an extra "u".

Usually making a home-made antenna costs more than what you could buy the antenna for. Problem is, you don't learn much buying an antenna pre-made. Good job with the homemade antenna!

Actually maybe not. With folks like jlpcb out there it would be easy enough to design a few different yagi, log periodic antennas and have different flavors ready in a few days for a few bucks on epoxy boards.
On the 'tube Andrew McNeill is the antenna guru . He actually inspired me to get my old-assed HP network analyzer. I love it. He does enough reviews of store bought purpose designed antennas to show that most are crap. Ace Hardware has all the hobby metals and tubing I ever needed. Ebay has given me sources for the best American made coax chunks and fittings I ever needed. Search "nearest first" and in a day or three as Kelly Bundy said...."Vi-Ola".

The strongest 2-3 GHz signal I could find around here with the TinySA was between -20dbm and -30 dbm. The signals came from a wireless router and cellphone. Both items were a few feet from the TinySA when these measurements were recorded.

My satellite noise floor seems to run around -70dbm. The documentation I have read says that reducing an unwanted signal to -55dbm will probably take care of any interference issue. So if I had a -30dbm unwanted signal that was interfering with c band, a filter of -25 db would take it down to -55dbm. A 45db filter would take the unwanted signal down to -75dbm. Providing of course the filters worked in the same frequency range as the unwanted signal. This is one way to use the TinySA analyzer to determine what you need to solve interference issues.

The geekery is not so geeky to me. I'd be interested to learn your findings for off axis persistence. In other words if you landed on 127W and a band of transponders were overwhelmed with 5G interference. In a normal situation shifting the dish 2 degrees E/W you would lose a channel (tp). How many degrees would 5G interference keep blowing into the dish and focusing on the lnbf?

[el bandido]

The geekery is not so geeky to me. I'd be interested to learn your findings for off axis persistence. In other words if you landed on 127W and a band of transponders were overwhelmed with 5G interference. In a normal situation shifting the dish 2 degrees E/W you would lose a channel (tp). How many degrees would 5G interference keep blowing into the dish and focusing on the lnbf?

There is not going to be a set distance to move a dish. Every situation will be different, and everyone does not have the same dish either. A quick look at the analyzer will tell you if in-band interference is present. The idea in moving the dish is to separate the interference from the satellite transponders. If you move the dish a degree or two in each direction and the interference goes away, then you either have no problem or you have a problem with one satellite. Also, separating the in-band interference form the satellite transponders will give a better view of how strong the interference is.

Every situation will be different.


As for the Vu+ tuner decision, you should have gotten what was being used in the MIO test. Simple enough. I guess we will never know the exact make of Vu+ product or the transponders being tested, and how they were being tested. Probably wouldn't matter much even if this information was available. Good luck with Vu+!

[armadillo_115]

I would think 5G interference from a terrestrial source to be harder to turn away from than a sat signal.

Terrestrial signal may be reflecting of trees, hills, buildings etc. Possible coming in from different angles. Stronger signal as well?

IDK how you could determine the specifics, but interesting to contemplate.

[el bandido]

Put in a simple, general way, The interfering signal has to collect on the dish in a large enough quantity to overload the lnb. The satellite dish looks up towards the sky. The cell tower signal looks down. The cell tower antennas have down-tilt built into them. Micro or mini cells, home internet routers, and even cell phones running c band frequencies can add to or cause interference. If you are in the down-tilt of the cell tower, then you have had a bad day.

No two interference situations will be the same. No two backyards will be the same. And not many satellite dishes will be exactly the same.All things equal, you could expect a smaller satellite dish to have more interference problems than a noticeably larger satellite dish. Then you have the location of the cell tower in the satellite arc. My nearest cell tower is almost due south where the dish is at its highest. Might be a different story for me if the cell tower was at 127w and I wanted to watch 127w. My dish is tilted down a whole lot more at 127w than at 87w.

The idea here is to fully understand what is going on in a particular situation. Once the interference is fully understood, then it can be dealt with (or not). The analyzer will not be clean when in-band interference is present. You can expect see lots of skinny lines mixed in with the transponders, or lots of skinny lines besides the transponders, depending on the frequency of the interference. The lines of interference may be a bit below, equal to, or above the lines for the transponders.

[el bandido]

I found a couple of videos on the TinySa Ultra that seem to have good and correct information about the product. These videos should be watched by anyone that thinks the TinySa Ultra is not displaying the c band frequencies correctly or within reason. The TinySa Ultra is probably not good enough for precise alignments at some frequencies, which reflects its price.Good, precision analyzers cost thousands of dollars.

[el bandido]

Software is available that allows the output of the TinySa Ultra to be displayed on a Modern Windows PC. Full features of the TinySa Ultra are not available in the PC software, but the basics such as scan frequencies are there. Plus there is a record mode.

For those on more of a budget or for those not wanting to spend much money, there are analyzers that work only with a Windows PC for around 40-50 dollars. A video of one of those devices is shown below. A spectrum analyzer like this is not what I want, but it would probably do OK for checking interference in c band. Pay attention to the specs of any small analyzer because some of them only cover in the MHz range. Other small analyzers only cover up to a couple of Gigahertz, but this would be OK for checking signals on a lnb, which would be 950-2150 MHz.

[el bandido]

Protect your analyzer or any other device that is connected to the powered lnb by using a splitter that blocks voltage on one side, or a voltage blocking connector. Don't "assume" that the voltage protection device works! Check the voltage on the port Before you connect to it. Even a small amount of voltage on a port will ruin a sensitive analyzer. Shown below are some of the items I purchased for voltage protection.


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[el bandido]

Already discussed is moving the dish East or West to see if the possible interference follows the dish, or to see if the interfering signals can be separated from the satellite signals. The dish can also be moved up or down (North, South). This is something I really don;t won;t to do. I have been blessed with a motorized dish system that requires very little attention. It stops when and where it's supposed to after a move, and the satellite dish has not been aligned in a couple of years.

Anyway, I will probably loosen the the big elevation nut while aimed at 87w and let the dish drop down.There is a multi-switch at the dish that will allow for an analyzer connection to see what happens as the dish drops. It will be interesting to see if the satellite signals disappear and the cellular c band signals get stronger when doing this.


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[Terryl]

I would not use a splitter as it will degrade the signals by as much as 3 dB,(or more at higher frequency's) I use an RF sampler, there are some available on line but you can easily build one your self, this link below has one, you can replace the in/out connectors he used with "F" type and what ever type your analyzer needs on the sample output.

https://www.worldwidedx.com/threads/rf-sampler.32110/

[armadillo_115]

Protect your analyzer or any other device that is connected to the powered lnb by using a splitter that blocks voltage on one side, or a voltage blocking connector.....

[Only registered and activated users can see links. ]

I have a similar setup so that one receiver supplies lnb power. (The other receiver no longer puts out dc voltage)

I have a splitter with voltage block on one side PLUS a dc blocker on the bad receiver. I figured it was safer in case either failed.