RF interference from IP POE

Olie

Olie

n3wb
Oct 9, 2017
26
4
United States, Midwest
Hello,

I searched the list and did not see this question answered so I'm throwing it out there.

I have a La View 8 channel IP POE NVR system ( lv-kns7286r4-t2) where one of the cameras is blocking me from receiving digital channel 11.1 on my TV's thought the house. I have a powered antenna in the attic and the cameras are attached to the soffits.

I've gone as far as trying to add RF magnet clips to the wire a s placing tin over the coaxial wire to the antenna.

Has anyone else seen where a wired system is pumping out that much interference through lan Lam cable from the NVR to camera or the camera it self ?

I do have an extra camera but I have yet to get up on the ladder and try to replace it and see if it's the camera , wire or NVR doing this.

Pretty frustrating because when the camera is not plugged in I get 4/5 signal strength for channel 11.1 .

Thanks for any insight,
Olie
 
Ethernet cables do radiate some RF noise. I think it would be unusual to have enough radiated emissions to interfere with tv reception but there are a lot of variables.

11.1 is a virtual channel not the actual RF channel the station uses.

What kind of antenna / amplifier are you using? Give complete models or links to the products if possible and describe or photograph the amplifier, power supply, and cabling. What type of cable is being used from the antenna to the TV? Where in the house is the TV antenna?

Where did the ethernet cable come from? What wire gauge is it? Is it solid copper?

How close are the the tv antenna, amp, amp power supply, and tv/power cables to the NVR, ethernet cables, and cameras? Where to the amp and nvr plug into power?
Anywhere you can increase increase the distance between things even by as little as an inch or two it will help.

Pictures would be very helpful.
 
tangent said:
Ethernet cables do radiate some RF noise. I think it would be unusual to have enough radiated emissions to interfere with tv reception but there are a lot of variables.

11.1 is a virtual channel not the actual RF channel the station uses.
Click to expand...

Actually regardless of the "virtual channel of 11.1" the frequency is the same 6 Mhz block. In this case 198 to 204 Mhz. Not a relevant or accurate statement. In fact it is exactly the "actual RF channel the station uses".

Might want to check that knowledge before pontificating. The OP was just trying to communicate the problem.

Something is clearly radiating on that frequency. But I agree more details would be helpful.
 
NoloC said:
Actually regardless of the "virtual channel of 11.1" the frequency is the same 6 Mhz block. In this case 198 to 204 Mhz. Not a relevant or accurate statement. In fact it is exactly the "actual RF channel the station uses".
Click to expand...
The virtual channels are the numbers your tv shows, they exist to preserve historical numbers associated with frequencies a particular station is using.
Without knowing the location of the OP, we can't know the actual frequency of channel 11.1 EDIT: hmm... 6-13 may be special in this regard, need to try to look that one up.

The channel number your TV displays is no longer an meaningful representation of the frequency a particular channel uses.
In many areas you'll see things like real channel 34 mapped to virtual channel 4.1. Sometimes they're the same, often they aren't. Sub channels are all part of the same channel.
Pop your address or zip code into tvfool.com and it will estimate the strength of different channels and show the real and virtual channel numbers.

As far as the OP's issues, it would be nice to know if their channel 11.1 is UHF or VHF-Hi, if their antenna can pick up VHF-HI, how directional it is, and how far away the tower is relative to other channels. In other words, is there something else correctable that would help with reception of that channel.
 
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Yes that is all true, but given that vhf high works great with 8VSB, no body I am aware of moved. But that doesn't mean this could be the one station that did. Of course that would be incredibly stupid and expensive, but hey you could be right.

The issue was that ATSC using 8VSB was somewhat compromised on the lower freqs like 2-6. 11 worked really well so no one moved.

34 was mapped to 4.1 in LA. Assume you are there although I recall other markets. As to the rest, I still call BS as while incredibly interesting trivia, not relevant. The cam is radiating on the channel he wants to watch regardless of frequency. Even if we know it is 578Mhz not 208Mhz. So what?
The camera is the offending device it would seem. Isolation might be possible.
 
Agree. "need to look that one up".

The only compelling reason to move to UHF if you were on VHF high was that antennas might only be UHF in the future (now). But most stations did not think that far ahead.

Are we off topic? OK , I say we it could be ME.
 
@NoloC you're certainly more in tune with the broadcast tv industry than I am. I agree the channel isn't that relevant, but issues with vhf-hi do seem more likely.

Some part of the camera system is radiating. Some possibilities:
- A defective camera
- Cable that's just the right length to cause problems and maybe isn't twisted right. I suppose CCA cable could have more issues as could cable that isn't terminated to T568B/T568A.
[basically I'm wondering if shitty cables that came with the cameras were used, if op terminated it did they follow the color code]
- NVR that spews a bunch of noise once the total load hits a certain point (unlikely)
- An issue with a particular port on the NVR causing an impedance mismatch and reflection.
- The camera's Ethernet cable is run right next to the power cord for the antenna amplifier and the amplifier is boosting the emissions
- This ethernet cable runs right next to the antenna coax for an extended distance (shouldn't matter, unless the antenna cable is really crappy)
- POS PSU for a POS amplified antenna that radiates a all sorts of emissions if you breath on it wrong.
(maybe, and I know it's a reach, some sort of coupled interference with a cable for the cam or the nvr, other power supplies in proximity)
- Twin lead feeding the antenna or crap coax cable / crimps (why 11?, maybe it's the weakest channel)

Some simple checks:
- Unplug a different camera and plug the offending camera into that port
- Re-arrange cables to put more distance between things
- Plug the NVR and antenna amp into different power strips with filtering
- Unplug the offending camera and cable and plug a different camera into that port

In summary, a picture or 5 is worth a thousand words.
 
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Well you are correct we need more info. I would suspect just a cam that is radiating on that freq. Would also wonder if powering off a 12vdc supply instead of poe would make a diiference.
Your trouble shooting suggestions are well thought out.

I was a broadcaster and went through the digital switch on a low vhf. Kind of like knowing how to do surgery on a pterodactyl as far as useful knowledge today.
 
I do not have the schema of you installation but do you use 12V passive PoE injection or is the 12V near the camera ?

Anyway switching power supplies are very noisy and a "particularly noisy" transformer can be the cause of your problem.

The Ethernet cable also act like an antenna and can radiate too.

The electronic inside the camera itself can also be noisy.

Can you draw a schema with distances of your installation ?
 
I"m using the lAN cables supplied with the LaView NVR. The antenna I'm using is in the attic near in the garage is a monoprice powered flat panel antenna. The builder put a nice coaxial connection for over the air antenna to the basement so the whole house uses it.

I'm using the 12v power through the NVR, no added power supply. I've even switched ports to see if it's the NVR router.

It's supposed to get nice here today mid 60's so I think the first trouble shooting would be to disconnect the camera and put up a new one and see if it changes vs rerunning and stringing a lan cable.

Thanks for the quick replys, I'll keep circling back if someone has suggestion and I'll give you and update.

Olie
 
The Camera IF frequency is probably the problem, if the NVR has a POE setting like Long Distance or Short Distance try switching to LONG. The long I'm guessing selects a slightly higher VDC and may help.
 
I doubt the NVR has a setting like that or that it would make a difference.
 
I just pulled down the camera and disconnect it, and it's still blocking the TV channel. So it appears it's the LAN cable that came with the kit, I have an extra one I can run and see if its a bad cable.

Fingers crossed because it's a pain to pull out the the bad one and put the new on in the conduit tube into the basement !!.

Olie
 
It's hard to say, I've disconnect the cable that runs nearest the over the air coaxial and it stops blocking it, I then plugged it into multiple ports on the NVR and it blocks the channel every time.

But it's the same cable so I'm not sure if it's a bad cable or NVR is spitting it out the interference and the camera that is nearest the coaxial is affecting it ? I do have one other camera near it that runs about 3 ft away and doesn't appear to have any interference.
 
Do you have a ferrite toroid, as usually fitted on VGA cables, that you could loop the ethernet cable though a few times at the NVR end?
These are aimed at reducing RFI where the frequency is much higher than the video signal.
But, in truth, I'm not sure if that would also have an adverse effect on ethernet signals, despite that they are differential, as they are around 100MHz.
 
Yes I was thinking that this winter and tried using them on the over-the-air coaxial and on the LAN cable at the NVR, no luck it didn't seem to make a difference. Worth a couple bucks to try though.
 
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