FTTC - Noise

I'm having issues with both my internet connection (and other radio devices such as my Evohome heating control system).

These issues seem to start in the evening for FTTC and are worst around 9-10pm. The Evohome is also problematic in the evening, however shows oddities all the time.

From my internet connection point of view I first notice that everything seems to slow down in terms of response time. Websites seem to stall loading for quite some time. Performing speed tests seems to show really low speed of ten to a couple of hundred kb's for 10-30secs then ramping up to normal speed.

What I have noticed is the the Noise Margin drops significantly when experiencing this problem but only for down not up. By example my usual noise margin hovers between 6.1 - 6.5 db throughout the day. However, when these annomolies happen the noise margin drops down to 2.3 - 2.4db. Upload remains at 5.8-6db

With regards to be Evohome (which operates on 868mhz) I am finding messages are not getting relayed from controller to relay (however are to the TRV's). This leads to house overheating, but the connection reported back by the devices shows 5/5 signal (and happens even if they are next to each other). Honeywell believe there is interference, which makes sense.

I have smart meters and notice the zigbee receiver complaints about signal loss, but then magically it comes back (even when quite close to the meters).

I am on a laptop connected by WiFi over 5ghz and the slowness is still present.

Any ideas what could be causing such a massive amount of interference to be causing issues across:

FTTC power levels
868mhz evohome messages
2.4ghz WiFi zigbee comms
5ghz WiFi my laptop

Apologies if the posts a bit loose on details and a bit sporadic. At first I thought it might be the construction of the house, but that wouldn't effect the FTTC surely at random intervals? Honeywell said they have seen fringe examples where smart meters have caused problems to their devices. EON refuse to back down and won't let me (nor them) turn the smart meters off to check.

Are you able to turn off the Evohome?

If so, I suggest you do so as soon as the FTTC problems start, and see what happens.

If there is interference behind this it is across a very wide frequency range since maximum VDSL2 frequency is 17 MHz.

Unfortunately not very easily as i'd have to go round and remove 12 TRV's, turn boiler off so relay could be disabled and take batteries out the controller meaning i'd lose all the settings on the controller (which frustratingly takes ages to setup) so we'd be without heat for while.

I will be able to try this, but unfortunately not quick enough to do it when problems start as the complexity of all the devices.

In reply to a post by MrSaffron:

If there is interference behind this it is across a very wide frequency range since maximum VDSL2 frequency is 17 MHz.

Have you ever heard of anything like this before (such a wide range that is?)

After many hours on with Honeywell they were very stumped. These issues might not be related however, it seems like this house really doesn't play well.

The only recent changes (as unfortunately not lived here long) made by me which could be related was:

- Longer tails placed on electric meter to extend consumer unit (cable is run through middle of the exterior wall approx 3.5m run)
- Smart meters

Oh, and a really long shot. The FTTC cabinet is placed very close to a weather / pollution monitoring station and slap bang next to a Virgin Media cabinet.

Edited by gary333 (Mon 04-May-20 22:59:34)

At around 11.10pm tonight the noise margin pops back up to 6.3db and the problem with internet not reacting seems to have gone away - until next time. All ideas welcome

If proximity to Virgin cab was issue would not stop at 11:10pm

Similar with monitoring station as usually on all the time.

You are looking for something that switches on/off by the looks of it.

Wideband interference means a FM or shortwave radio might be useful to help track down the noisy device (devices) and turn things off in turn until you finally pin down the culprit

General rule is if this was not an issue before last electrical change to suspect what ever was added/changed is the culprit

Try Mr.S’s suggestion, go buy a cheap battery powered MW radio. Have it tuned to about 612 MW and have a listen around the property .....
I’d suggest trying when there is no interference apparent ... then again later when there is ....
Most likely symptom will be a pronounced ‘growl’ on the radio. If you pick one up, try turning stuff off at the mains till you locate a possible source.

**Hunting REIN isn’t an exact science**

Cheers both, will give that a go. Is there any way of checking outside to see if the problem is external, would it still be the radio scenario?

Although the noise margin increased to 6.3db at around 11:10pm last night. I noticed the WiFi was having problems I described above and things not loading (until I turned wifi off on each device and back on, or restarted them).

This problem was happening until well after 12am (after which I went to bed).

I got an email from the Evohome @ 4:30am saying connection restored, so after checking the TB connection quality monitor can see it was out for a few hours in the early hours.

Edit - Added TB Monitor link My line

Edited by gary333 (Tue 05-May-20 07:41:23)

See if you can find a nearby radio ham. Either (1) they will have the equipment to help you locate the problem, and will be delighted to help you do so; or (2) they will be the problem