Filtering DECT phones

[Captain Jack]

How can I filter DECT phone frequencies? I have interference around 12480 and 11630 frequencies, which a tell tale sign of DECT playing havoc.

I only get this from my motorised dish, whose cable goes through various hoops (Vbox and a splitter). The T90, which has a direct cable run from the dish DiSEqC switch inside the house, doesn't seem to exhibit these symptoms. So I am guessing the interference is getting somewhere through one of the intermediaries...

First step will be to try getting rid of the VBox and the splitter and reintroducing them into the chain and see which one is the culprit. But beyond that... what do I do? The phone base is nowhere near the receiver or the cable run, so there must really be a big hole somewhere....

 

[Lazarus]

Are you sure its your DECT kit, not some cheap non-compliant one next door?

 

[Captain Jack]

Hmmm, nope - not sure but I am in a detached house and the only plausible point of entry is from either the VBox or the splitter, which is inside my house.

 

[Ghostleader]

Same type of cable Jack? I had this problem with some cheap air spaced RG6 cable I had at my old address setup.

 

[Captain Jack]

Same cable, just one is white, the other black.

 

[Ghostleader]

Cheers Jack not that then, Does the vbox have a plastic outer case? That was a "thing" I had with a cheaper sat receiver, the DECT waves were just passing through the case and onto the tuner board, moving the DECT base station out into the hall stopped the interference but nowt else because of its location in the living room.

 

[Captain Jack]

Yeah, all plastic with little shielding at all. The base station is downstairs and Vbox is upstairs.

 

[Ghostleader]

So any kind of RF can piggy back along coax but this obviously varies depending on what strength of source interference ect but IF this is what was happening then the Vbox with its poor/lack of screening is looking a better bet than the splitter.

 

[RustySpoons]

Have you tried ferrites?

 

[Captain Jack]

Ferrites on where? I thought these we only for reducing mains hum (mainly)

 

[RustySpoons]

Around cables, coax, mains cable etc.
Also look at making an ugly choke/ugly balan by coiling up some coax to see if it's coming in on the braid.

And no ferrites work on many frequeinces.

 

[Mickha]

I had this problem with my set up, V-Box II and VU+ Duo2, in the end I ran a telephone wire, from the downstairs box, to the upstairs, where I placed my main telephone, and thus had the others no where near my satellite gear, this worked.
I noticed it most on Sport 1 Germany, the FTA standard sports channel, on 19.2E.

 

[RustySpoons]

If you must have a DECT Phone, Siemens are the only ones I know of that don't cause interference to anything, they have a special mode you can put them in called ECO Plus.

 

[a33]

Yeah, all plastic with little shielding at all. The base station is downstairs and Vbox is upstairs.

Not only the base is sending. Where are your handsets?

greetz,
A33

 

[Captain Jack]

Not only the base is sending. Where are your handsets?

Oh.... there's one in my room...

 

[Channel Hopper]

How can I filter DECT phone frequencies? I have interference around 12480 and 11630 frequencies, which a tell tale sign of DECT playing havoc.

I only get this from my motorised dish, whose cable goes through various hoops (Vbox and a splitter). The T90, which has a direct cable run from the dish DiSEqC switch inside the house, doesn't seem to exhibit these symptoms. So I am guessing the interference is getting somewhere through one of the intermediaries...

Before going to the expense of changing , rewiring and relocating things, have you tried changing the LNB on the motorised dish ?

 

[Captain Jack]

Hm no... though pretty sure it was like that with other LNBs when I had them on. The LNB is almost 20m away at the bottom of the garden though...

 

[Channel Hopper]

It's not so much the distance, but the design of the LNB itself, and specific points down the line where interference finds its way in to the receiver tuner.

A change of LNB can sometimes suppress the weak points sufficiently.

 

[Mickha]

It didn't matter what make of LNB, I used, still the same problem, it did ease, considerably, when I took the V-Box II out of the system, but as I need it I decided on moving the telephone.
I assume you have tuned into a problem channel, like Sport 1, and unplugged the DECT telephone, as that's how I located the fault.
The problem also eased when I replaced the cable runs, with new cable, as they were a number of years old, but it only fully disappeared when I moved the telephone out of interference range.

 

[Ghostleader]

If you have tried other LNB's then that rules that out but the problems I had with the Inverto Black Ultra were similar to that of DECT interference but not exclusively on the tell tale frequencies that DECT messes with.