TV Interference From CH Boiler

[drlabman]

I have a similar problem to this, except that I am using a HDMI extending device, using two cat 5e cables, and the interference happens when I turn on / off a nearby light switch to these cat5s .
Could be worth trying a better screened HDMI cable.

Thanks, I'll add that to the list of things to try.

 

[Terryl]

If the TV in question has the RFI ferrite's installed on the power cord to the TV then that would eliminate the chance it's directly coming into it via the AC mains.

This is looking to be a EMP pulse from the boilers ignition circuit, they make ferrite snap on's for the coax cable, I would try some on both the satellite and TV coax, this may cut down on direct RFI to the TV/Humax, also since the Humax uses an external DC power supply you shold get one for it also.

I would check to see how the case of the boiler is grounded, is it just through the electrical cord/connection, or is there a real external ground?

If the boiler's water supply piping is metal (iron pipe or copper) then it should be/ could be grounded through the water supply piping.

This however could cause a problem if the two grounds are at different locations, if the two grounds are far apart (case ground and electrical ground at the AC mains service/fuse/circuit breaker panel) it could be causing a ground loop problem, this could make things worse.

I have seen problems where the equipment is grounded through the electrical service ground only, and the equipment is located a ways away from the AC main panel, this was a long ground wire, connected only at the main panel, this cause a ground loop problem and the RFI was radiating off the long copper wire going back to the panel, it acted like an antenna.

Many possibility's here, I wish I lived close by , I would have hopped in the truck with some equipment and helped work this out.

Oh, do a google search for a cheap AM radio from someone at your location, and one with a manual tuner, I found some below 15 USD on amazon, the radio will tell you if its an EMP, and EMP covers a very broadband frequency spectrum, if you hear a POP on the radio then it's an RF EMP and that's a hard one to cure.

 

[Terryl]

Note to others: An AM radio (cheap one with manual tuning) makes a great lightning detector, when tuned to a location on the dial without a station on it you will hear a pop or crackle when the lighting hits somewhere, counting the seconds and dividing by 3 will give you an idea on how far away the lighting hit was in Kilometers.

 

[deeptho]

Note to others: An AM radio (cheap one with manual tuning) makes a great lightning detector, when tuned to a location on the dial without a station on it you will hear a pop or crackle when the lighting hits somewhere, counting the seconds and dividing by 3 will give you an idea on how far away the lighting hit was in Kilometers.

You can also use blitzortnung.org to see the strikes happening anywhere in the world...

 

[PaulR]

Or this web site

Real Time Lightning Map

See lightning strikes in real time across the planet. Free access to maps of former thunderstorms. By Blitzortung.org and contributors.

www.lightningmaps.org

 

[drlabman]

If the TV in question has the RFI ferrite's installed on the power cord to the TV then that would eliminate the chance it's directly coming into it via the AC mains.

This is looking to be a EMP pulse from the boilers ignition circuit, they make ferrite snap on's for the coax cable, I would try some on both the satellite and TV coax, this may cut down on direct RFI to the TV/Humax, also since the Humax uses an external DC power supply you shold get one for it also.

I would check to see how the case of the boiler is grounded, is it just through the electrical cord/connection, or is there a real external ground?

If the boiler's water supply piping is metal (iron pipe or copper) then it should be/ could be grounded through the water supply piping.

This however could cause a problem if the two grounds are at different locations, if the two grounds are far apart (case ground and electrical ground at the AC mains service/fuse/circuit breaker panel) it could be causing a ground loop problem, this could make things worse.

I have seen problems where the equipment is grounded through the electrical service ground only, and the equipment is located a ways away from the AC main panel, this was a long ground wire, connected only at the main panel, this cause a ground loop problem and the RFI was radiating off the long copper wire going back to the panel, it acted like an antenna.

Many possibility's here, I wish I lived close by , I would have hopped in the truck with some equipment and helped work this out.

Oh, do a google search for a cheap AM radio from someone at your location, and one with a manual tuner, I found some below 15 USD on amazon, the radio will tell you if its an EMP, and EMP covers a very broadband frequency spectrum, if you hear a POP on the radio then it's an RF EMP and that's a hard one to cure.

Just to confirm, the TV mains lead has 2 ferrites on it - one at both ends. The DC power into the Humax box has a ferrite on it.

So, as you say, the next thing to consider is adding ferrites to the coax to the Humax, and also perhaps the TV coax. Where should they be connected?

I have a radio with an AM tuner somewhere - just a matter of digging it out.

 

[Terryl]

The ferrite's for the TV and Humax coax should be as close to the inputs to both as possible, these may or may not help but it takes one possible input out of the question.

 

[Terryl]

Any updates on this ???

 

[drlabman]

Any updates on this ???

I'm sorry I don't have any updates yet. I have a load of other work going on in the house at the moment and haven't had spare time. I'll be sure to update the forum as and when I get somewhere. Also, for the last few days the weather has been pretty clear - and the problem tends not to happen in good weather, so hard to test.

 

[Terryl]

Hummm not happening as much in good weather, that's strange..

 

[drlabman]

Hummm not happening as much in good weather, that's strange..

My thinking is that the signal is "good enough" is good weather but during bad weather it's marginal and any interference tips it over the edge. This could be due to slight dish misalignment, age of the LNB, age of coax cable from the dish.

 

[tv_sinclair]

Mebbe im wrong, but I thought digital signals couldnt get interference as against AM which could..or am i misremembering my tech college info. In my own case I get tv wipe out at night on RF channels through the Skybox upstairs but no problems on Freeview. Never managed to find the problem, used to think it was coming through the aerial input but even removing it from the Skybox, it made no difference. One day Ill try a rewire.
To avoid confusion its from RF2 to the bedroom that gets interference

 

[rolfw]

Mebbe im wrong, but I thought digital signals couldnt get interference as against AM which could..or am i misremembering my tech college info. In my own case I get tv wipe out at night on RF channels through the Skybox upstairs but no problems on Freeview. Never managed to find the problem, used to think it was coming through the aerial input but even removing it from the Skybox, it made no difference. One day Ill try a rewire.
To avoid confusion its from RF2 to the bedroom that gets interference

Yes, you can be affected by interference on Digital as well as Analogue, it just manifests differently, your RF2 feed from the Sky digibox is an analogue feed, so yes, could be the cable, could be the frequency it is set to, could be the aerial plug, could even be the box. When first launched I seem to remember the rf2 out was set to channel 68, which is now amidst the 4G and 5G signals, which output channel is yours set to and is the rf2 output fed into a distribution amp?