Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Bowdon]

Over the past couple of weeks I've noticed the hotter the temperature is the lower my SNR levels go.

My SNR on my download used to be around 6.3 then as things got hotter it gradually started dropping. Over the last few days its gone down to 5.4. On the upload SNR its usually always above 6.2, but now even that is down to 5.7.

It's currently 22C here. I'm wondering if those ECI cabinets have fans in them or something to extract the heat out of them.

The only other theory I have is that more people are pulling electricity off the grid and that's interfering with it. When the town had a power cut, most people in my area had no power, while I did. My SNR shot up to about 8 in that duration. Then dropped eventually when other peoples power came back on.

[roseway]

The electrical resistance of copper increases with temperature, so the attenuation will increase to some degree. It's difficult to work out how much increase there is, because attentuation is dependent on more than just the resistance of the cable.

[Weaver]

connections expand too, so the pressure on contacts can either go up or down, depending on which bit expands more. A lot of factors to consider.

for a bit of fun, (i) point a big fan at the modem, or (ii) zap the whole thing with freeze-it spray (perhaps best done only if it's your own device, not BT's property). (iii) Could even dip it in a bucket of liquid nitrogen (slowly). :-/

[N0STIE]

My SNRM dropped from about 10dB to 9.0dB in few days. My attainable has been reduced as well althrough haven't noticed any packet loss or loss of speed. Anyone can explain that?

[Bald_Eagle1]

Over the past couple of weeks I've noticed the hotter the temperature is the lower my SNR levels go.

The only other theory I have is that more people are pulling electricity off the grid and that's interfering with it. When the town had a power cut, most people in my area had no power, while I did. My SNR shot up to about 8 in that duration. Then dropped eventually when other peoples power came back on.

I see exactly the same effects here.



As an aside, my connection has been affected by thunderstorms over the last few days, especially last night:-

http://forum.kitz.co.uk/index.php/topic,15675.msg292058.html#msg292058


As you live only around 3 miles or so from me, has your connection also been affected by these recent storms?

[PhilipD]

Hi

I don't think temperature acting on the copper wire will be causing an SNR drop of any significance as the temperature co-efficient of copper doesn't cause that big a swing.

It's more likely to be your own equipment running hotter so the noise floor rises, mostly caused by degrading capacitors that don't like running warm anyway, and transistors create more noise when their junction temperatures rise.  Equally or as a contributing factor the sun baking the cabinet and rising the internal temperature will also have an effect.

The power cut causing an increase in SNR is because a lot of cross-talk disappears as modems drop.

Regards

Phil