WiFi Interference etc

Posted by: Mr Frog on 13 February 2015

I have an ageing cordless DECT Panasonic phone/answering machine which operates in the frequency range of 1.88 GHz to 1.9 GHz

 

I was wondering whether it is likely to interfere with the quality of the wifi connectivity (iPads, iPhones and computers etc) or even a source of RFI to the HiFi - albeit these components (Naim ND5XS, NAS etc) are wired Ethernet connections and incorporate a Netgear switch.

 

The cordless phone seems to still be going strong despite its age (2006) and to be fair, we tend to use iPhones for most calls, rather than the BT landline. As such, I'm not in a hurry to replace it, unless of course it is a potential source of interference and detrimental to both sound quality and the home Network.

Posted on: 13 February 2015 by Huge

Do you have ferrites clipped onto the leads of its base-station?

Posted on: 13 February 2015 by james n

Unplug it from the mains temporarily. Does your system sound better - 

 

Yes - follow Huge's advice above.

 

No - Don't worry. 

Posted on: 13 February 2015 by Mr Frog
Originally Posted by Huge:

Do you have ferrites clipped onto the leads of its base-station?

Thanks for the response Huge.

 

No Ferrites are fitted to either the power AC cord nor the BT telephone cable fitted to the base-station, but I can certainly fit these. I was just concerned that the 'signal' emitted by the cordless phone itself may introduce unwanted RFI through the 'airwaves' - but I guess when the cordless handset is sat charging in its base-station (answering machine) and not actually in use as a phone, then perhaps there may not be any unwanted signal emitted by the device (?)

Posted on: 13 February 2015 by Bart

I am tempted to recommend wearing a tin-foil hat and "space blanket" while listening, but I'll refrain.

 

No worries about your cordless phone.  Cordless phones can interfere with wifi if the home wifi is broadcasting in the same band and on the same channel.  Microwave ovens can interfere, too.  Most home hifi access points have some ability to seek a 'clear channel' or at least to allow you to select one yourself.  If you're not having unexpected connectivity issues with your devices, I'd move on to worrying about something else.  We have plenty to worry about in the land of hi fi esoterica!

Posted on: 13 February 2015 by Huge

The radio signal used by the DECT phone is very narrow band and is unlikely to interfere with your WiFi or the Hi-Fi (although it is possible).  The Panasonic phones are good quality and this also helps.  Most Panasonic phones have an <Eco-Mode> where the RF power level used for the 'keep-alive' paging is at reduced power; if you have concerns enabling this would be a good idea.

You are much more likely to get interference into the Hi-Fi form mains RFI from things like industry and switched mode power supplies.

 

Here's a white paper with some guidance...

1.02    https://drive.google.com/file/d/0Byjlr9brl1ykUDg1dUNzSTNVS28/view?usp=sharing

but don't get too hung up on it, most people don't have that much of an RFI problem and don't need to go as far as I had to.

 

 

Bart, maybe the Hi-Fi should have the tinfoil hat?

Posted on: 13 February 2015 by Mr Frog

Thanks guys 

Posted on: 13 February 2015 by Guy007

A useful tool for seeing what other neighbouring wifi (not DECT) could be effecting yours in addition to seeing the strength in different areas of your house is inSSIDer - it works on Mac and PC.  Based on what it shows, you could then change to a better channel on your home router with less interference and move the router to a better position to enjoy a stronger wifi signal.

Posted on: 13 February 2015 by Noogle

If you're worried about interference from your DECT phone, you should certainly be worried about your iPhones.  Try placing one on top of your preamp.

Posted on: 13 February 2015 by 40 below

The simple test is to unplug it and see if there is a difference.  My previous phone was causing significant deterioration.  

 

After some investigation I replaced it with a Siemens Gigaset model, which has an ECO-DECT+ Mode which shuts off transmission when not in active use.  This was inexpensive and a very substantial improvement. It's SMPS seem relatively quiet, too.