Interference!!!

[steepeljack69]

Hi if anyone can help in any way it will be much appreciated. I have just moved into a semi detached bungalow,a elderly lady lives next door.Now iam knocking her TV out and if I go onto 11m ialso take her landline out,and no iam not using loads of power.Anyway I resolved the fone by moving my Gainmaster up a few feet.But here's where it gets weird,I have just got a dmr handheld now when I plug it into my co linear which is just above my gutter outside her freeview is going off again,this is only with 5w.So I went in to look at how she gets her TV signals,now the aerial on the chimney is straight into the TV which is a newer flat screen.There's no booster box as we do struggle to get freeview as we r out in the sticks.So I took my dmr handheld round to hers,keyed up and her freeview went off ,why?I can stand right next to my TV and nothing happens!pls if anyone has any ideas what could be going on??Because I caused her interference if anyone has the slightest bit of picture break up its me!!I won't use my radios as I am worried I will cause interference, I feel like selling up,it was a bad move here.thanks.

[clayhead]

Make sure the aerial on the chimney really does go to the TV.
Check if the outer shield on the coax has no breaks and is securely fixed at the aerial end and the TV end.
Hope this helps and let everyone know how you get on.

[owza]

The RSBG might be of help here.

http://rsgb.org/main/technical/emc/i-am ... akthrough/

They also stock filters / Ferrite Rings etc
http://rsgb.org/main/technical/emc/emc- ... rsgb-shop/

I guess the RBF1/70 cms notch filter (RSGB order code Filter 5) should also work with DMR. Assuming it's a 70cm DMR set you have?

Good luck with this, it's every hams nightmare.

[grafter]

If all else fails offer to 'upgrade' her to Freesat HD but I'd start by checking all aspects of her TV aerial, some of them have been installed since the 70s and the coax (and driven element) is long since knackered. Replace that with something like CT100 and add a high pass braid breaking filter before any amps. As Clayhead says, please update us on the outcome, nothing worse than finding a useful thread in months/years to come only to not see the cure or final result.

[Admiral]

Just wait for her to die and then carry on.

[paulears]

I can recreate this with a DMR inside, and in my place. The DMR wrecks the freeview signal, and the business frequency repeater flickers the screen when it keys up. In my case the TV aerial feeds a distribution amp in the loft. The aerial is about 10m away from my repeater aerial. The Samsung TV set doesn't pay any attention, and seems immune. The receiver that suffers is a cheap set top, connected to a professional Sony metal cased monitor. The direct path from the DMR gets in via the plastic case. Wrapping the receiver in foils proved that one. As modern digital TVs do not suffer from the old style interference, where you could see it on the screen, Digital just seems to lose sensitivity. Damn hard to trace and fix.

[GeeFull]

Just wait for her to die and then carry on.

According to modern statistics, people are living longer, could be a well drawn out wait, so maybe a technical fix might be the way!
Is the DMR activity amateur based, or at least PMR licensed?
If it is give Ofcom a ring, might just be a completely crap TV, wouldn't be the first time, and no technical fault of your own.

[steepeljack69]

Cheers everyone,av had a look at the coax to the TV which looks fine.The problem is she's 87,doesn't like change and when I offerd to pay for the aerial replacing she told me NO!her nephew has told her it's a top TV aerial,tried to explain but not getting anywhere??I have told her the council or police will do nothing about the interference. I have warned her if Ofcom do come out and find its her stuff that's not up to scratch she will get the bill.Iam running a brand new ft991,so I don't think it's my stuff.I have tried been a good neighbour and have had her bungalow fixed up as the council aernt botherd,by keeping her on side the council aernt here telling me to take my Aerials down.Only thing as it is I can't get on the radio,also did I mention I was coming over her landline?I honestly think all this is to do with how the council re wired my bungalow ,the electrics aernt right.My pal says it's not earthed correctly,any thoughts?Thanks.

[Admiral]

My pal says it's not earthed correctly,any thoughts?Thanks.

Borrow an insulation meter, should be around 500ohms from earth to live, 1k max if exposed to moisture, 0.00 is a dead short and not good.

That is a proper insulation/isolation meter, not a ten quid multimeter.

[steepeljack69]

When my mate said the earthing wasn't correct sum guy showed up from SSE,they do the rewires for the council.He had a big piece of kit hung round his neck, told me nothing is wrong and tell my mate he's talking crap!!Anyway he went I moved in and if I try one plug it trips everything out!That's not right,whatever I plug in it trips!!My pal says when they rewired they put wet plaster on the cables and its done sumat.Pls don't have a go at me if thats sounds stupid,I know very little about electronics.

[Tigersaw]

Silly question, but does it trip everything out when you put the plug in, or when you turn something on plugged into that socket?

[Admiral]

That bit of kit around his neck was probably an insulation meter, hopefully he/she killed all the AC to the property as it fires 500v DC down the system to get it's reading, over 800ohm can cause RCD tripping with moisture.

[steepeljack69]

It trips out when I plug a item in,yes I turn the socket on .Doesn't matter wat I plug in it trips,yet I can plug same item in the other side of the wall and its OK.

[Tigersaw]

So, if you turn the socket on, nothing plugged in all ok. If you plug something in, it will trip once you draw power but not just by pushing the plug in. Just trying to eliminate something physical with the socket. (seen it before where the wiring was not insulated and the mechanics of the earth pin releasing the live made a short)

[mountainpenguin]

I had a socket that had rusted due to a leak in the wall
almost a pure short to ground from neutral in the end!