Well I've managed to get a portable AM radio and have tuned it inbetween stations (lots of hiss but no station audible) and wandered around the house. The TV downstairs gave off a clicking noise, a louder noise near the wireless alarm box and also a noise with the TV in the same room as the router.
Turning off the TV's at the wall has stopped any noise but has no obvious effect on my SNR (if it should) but the alarm is going to be tricky to turn off.
Not sure if I'm doing the radio correctly as I'm getting feedback from pretty much everything! lol

In reply to a post by Fantasmo:

Not sure if I'm doing the radio correctly as I'm getting feedback from pretty much everything! lol

DMT and indeed Routerstats, will show you the bit loadings per tone on a graph.
The graph may show certain dropouts which can be tied to a radio frequency. You can tune the radio in to those frequencies and see what's broadcasting...

I'm running with RouterStats Lite at the moment.
I've not had any drop outs as yet, just a non-fluctuating period which seems to get progressivly worse.
I don't think the lite version shows the bit loadings. Will have to look into that another time.

Ahh indeed, yeah thats fine for upstream. With it being 15db. about 3mbps is being robbed probably due to disconnects.

Well I've had RouterStats running all night and it hasn't diconnected yet although from 21:30 to 03:30 the SNR is erratic. 03:30 onwards the SNR has been completely stable with nothing going on in the house (i.e. fast asleep).
Will leave to monitor for rest of day.

Those times tie in with the Sun. The E-layer rises at night and reflects radio from further away, increasing noise.
http://www.tiscali.co.uk/reference/encyclopaedia/hut...

London, United Kingdom
Sunrise: 4:42am
Sunset: 9:20pm

Edited by deleted (Fri 19-Jun-09 08:38:47)

Your times are one hour slow

take away an hour, add an hour.

You've got the wrong layer - it's the D layer that reflects HF signals. The action of the Sun on this layer isn't instantaneous, so there is no dramatic changes between day and night - the effect is gradual.

I've left my computer on at home to monitor the connection and am using LogMeIn to see the log from work (don't tell the boss!).

What I've found is the following so far -
18/06/09 18:30 to 20:30 - Pretty stable SNR at 11db
20:30 to 03:35 - High fluctuating SNR between 13db and 6db
03:35 to 08:15 - Flat 11db. No movement
08:15 to present - Predominantly between 13db and 11db. 1 spike to 7db

All electrical appliances near router have been unplugged and no one in house since 09:30.
I have called the house as a test and see no sudden spikes relating to phone call. I'm convinced the problem is an external interference now.

The sun rises at the back of the house and sets at the front. The cable and pole is at front of house.

To me, it looks like you're suffering with increased radio noise at night, caused by whatever layers in the atmosphere. The standard cure for this is to remove the ringwire and ensure you have shielded wiring as much as possible, and generally sort out your phone wiring.

That spike during the day looks like another instance of radio noise, although cause by something else. It could also be a line fault - AAISP would help.

In order to understand what's going on, you really need to look at the tone graphs mentioned earlier.

However, it's safe to say with a lower SNR margin, these events would cause disconnections.