radio interference on door entry system

[goldie]

Hi all.
Got called to a door entry system fault. It's a new install but I suspect the guys who did it ran the cables with no consideration to segregate from mains cables. My jaw dropped when looking at the rest of their work.
Anyway 9 appartments and an outdoor speech unit and all all handsets you can hear radio 5 live frequency 909 in the background.
Anybody know what kind of suppressor required and where to terminate to snub out the interference? If I'm on the right thought process of course.
Thanks in advance

 

[Darkwood]

New install?... What about they come and rectify their work under guarantee while you prepare a shopping list of issues of their professional work ....cough cough

Check also the data cable they used between phone and Entry is 240v rated sheath if run alongside mains cables, picking up radio signals is not usually down to running along side mains as this would be a noise not a radio channel, it may be the case its following a run with speaker cables unsheathed like figure of 8 but interference is a tricky thing sometimes and may take some figuring out.

 

[tazz]

Had this one myself on a basic 4 way Fermax, cables were run next to tv distribution cables in the riser. Installer had used 6 core security cable which din`t help either.
Replaced cables with screened Beldon twisted pair. Problem solved

 

[Darkwood]

Had this one myself on a basic 4 way Fermax, cables were run next to tv distribution cables in the riser. Installer had used 6 core security cable which din`t help either.
Replaced cables with screened Beldon twisted pair. Problem solved

Lucky tenent wasn't watching P.o.r.n...would be for some supprising expressions at the door.

 

[tazz]

lol.........tbh, you could only hear it late at night, but system just seemed to pick up the strongest signal, via the tv amp.

 

[Darkwood]

lol.........tbh, you could only hear it late at night, but system just seemed to pick up the strongest signal, via the tv amp.

Not my strongest area but sounds like it was saturated in peak viewing times and probably just had a quiet garbled hiss during day but hard to hear, as the tv's were turned off the remaining signal were not competing so were picked up well and was helped with the quieter nature of night ....at a guess anyway but either way having the correct cable rectified all issues.

 

[goldie]

Going back to the first reply. Customer can no longer get in contact with yhe polish team that installed originally ('poor man now paying twice') Replacing cables is not really an option as this was a refurbished of an appartment block and all has been plastered and decorated now.
I spoke to the manufacturers and they say it's more than likely down to the cabling acting as an antenna.
Nobody know of any suppressor or anything that can snub out the frequency?

 

[tazz]

I doubt you will get rid of it using low pass filters....this is a cable issue, and replacement is the only answer.
I sorry, but he went for the cheap option of unskilled labour....now he`s paying the price. If he wants to pay you to replace cables then great...otherwise, not your problem, walk away

 

[SJD]

As mentioned screened cables might be needed, but it might be worth at least trying some filtering, a low-cost option that might (or might not) solve the problem. Sounds like there is RF getting into one or more (or even all) handsets and outdoor unit, you might need to filter all of them to have any effect.

Depending on how wired, is it possible to disconnect 8 of the handsets, and test just one handset with the one outdoor unit, and add filtering to either or both of these? As to what filtering is needed, I'm not an expert on these devices, but possibly winding the cable a few turns through a toroid where it enters the handset/unit, and/or some low-value capacitors from each signal to ground (always assuming there is a decent ground).

I'd be inclined to say up front the system might need rewiring, but you are prepared to see if filtering will help, with no guarantee.

 

[shanky887614]

As mentioned screened cables might be needed, but it might be worth at least trying some filtering, a low-cost option that might (or might not) solve the problem. Sounds like there is RF getting into one or more (or even all) handsets and outdoor unit, you might need to filter all of them to have any effect.

Depending on how wired, is it possible to disconnect 8 of the handsets, and test just one handset with the one outdoor unit, and add filtering to either or both of these? As to what filtering is needed, I'm not an expert on these devices, but possibly winding the cable a few turns through a toroid where it enters the handset/unit, and/or some low-value capacitors from each signal to ground (always assuming there is a decent ground).

I'd be inclined to say up front the system might need rewiring, but you are prepared to see if filtering will help, with no guarantee.

i doubt that would help, thet used unscreened cable all the way.

belden is 2 core twisted+screened to reduce interference

 

[goldie]

Thanks for the advice!