Massive drop in sunny weather?

[#1]

My troubles persist with poor connection speed and now very low SNR reading of down to 1.9. I notice the big drop when the sun shines as it has recent weeks. During the Sept 12 to march 13 i had a good connection at upto 1200+kbps (good for my long line) but it went downhill in early May. Lost the speed connection down to 1024kbps and since last week it has fallen to 800kbps. A reboot got it ti it's current 928kbps, but what i cannot explain is the sudden drop in the SNR reading off routerstats which shows very low SNR reading. This morning was cloudy and the day started at 5.4 SNR (noise margin), at 11 a.m. the sun came out and now I fluctuate between 2.9 to 1.9. As evening comes and the sun goes away I am back to 5dB. Spoke with PN technical dept who said nothing is wrong and until I drop to 250kbps it is not considered a problem. Normally when the sync rate drops the Noise Margin increases to about 7-8dB but not recently. Only observation I can find is it happens when the hot sun is shining. Any thoughts?
To try and alleviate my problems I have just purchased  Billion 7800n but looking at the manual (prior to receiving the modem/router) it looks frightening to set up! Should I be concerned. Would anyone who has the Billion 7800n let me know if it is easier than the manual is describing.

[#2]

Hi there,
I've run a few checks on your line and noticed that your line is erroring quite often, are you able to connect to your test socket to see if there's any difference?

[#3]

I am the complete opposite this heatwave and sunny weather is great I have hit the jackpot for the first time 10mb it seems the hotter it gets the faster my broadband,I just had to report the good news I hope my router keeps cool.

[#4]

Any solar panels nearby that might contribute towards the noise, more so when the sun is shining?

[#5]

Test socket is the same.
No solar panels within 1 mile.
Attaching some segments of Routerstats log for your review and comment

[#6]

I can see you've raised a fault which is something I would have recommended anyway.
I'm wondering if there might perhaps be an exposed cable joint that's expanding in the heat and causing some issues?

[#7]

Yes Adam, I have that  felt the recent heat has definitely been related to the problem. On a cloudy day, as what it was during most of winter/spring, no problems. Direct 25-30deg sunlight and the problems begin and persist. I think some joint and/or copper somewhere is having a detrimental effect by expanding. As i write this having just switched on and the sun lower in the sky, I am on 4.8dB. Not good but not 1.1 as it was in the peak of the afternoon.

[#8]

I have had no technical response to my fault Ticket raised on 17July, only the usual acknowledgement of the ticket being raised.
Heat on the telephone line at a joint or somewhere is my conclusion, as today is overcast and no direct sun, also cooler at present as I write and guess what? Yes my Noise margin is 6dB !

[#9]

Support Team have responded to my fault Ticket by telling me they are putting me on 1 mb fixed line by tuesday. I was hoping for some advice on the problem and an option to discuss, but PN have gone ahead and arranged the change. I can of course phone them to ask for this not to be done, but I have no idea if this is a good idea, what the pitfalls are and whether it is reversible. My understanding is that if i should lose connection it will not reconnect, is that correct and if so what do I do? How long to get reconnected? What speed of connection will I have...1024 solid?
Too many unknowns for me, so I think all things should have been explained before a decision was taken on my behalf. I have replied to the Ticket but would appreciate some members advice or expert opinion on what I should expect based on my questions mentioned in the previous paragraph.

[#10]

Apparently the downstream adsl sync rate for a 1Mb capped rate profile is 1152. I'm not sure how it will help if you're having difficultly reaching 1152, perhaps it will let you connect at 1152 with any noise margin greater than zero.

[#11]

I'd be inclined to give this a try. The change is not permanent, you can be moved back to ADSLmax if required.
On a 1Mb fixed speed service, as ejs said your downstream sync speed will be 1152kbps and upstream 288kbps (I think). Interleaving doesn't apply on fixed speed, so it will be fast path. Note that as on ADSLmax actual throughput will be lower than the sync speed due to overheads.

[#12]

Spoke to PN this morning who tell me the connection speed would be 1000kbps not 1152. As I am already at 928 I see no advantage at all. This morning again is grey and overcast with no sunshine and I am 6dB noise margin. I have spent £100+ on a Billion 7800n due for delivery this week which I want to try out so have asked PN not to proceed with the Fixed Line option. If I was going to be on a fixed rate of 1152 and a 1megabit profile I would have proceeded as that would have been good, if stable. When I install the Billion I will obviously disconnect my current connection during setup and I almost guarantee that if I do so in overcast weather conditions, I will reconnect at a higher speed than 1000kbps.

[#13]

My understanding is that the sync speed on a 1Mb fixed speed service is 1152kbps with an IP Profile of 1000kbps. Upload sync speed would be 288kbps, around 250kbps best achievable, actual 220kbps? (significantly slower than 390kbps best with actual speed 350kbps on ADSLmax).
Since fixed speed is fast path, correcting errors would require retransmission and your connection seems prone to those in hot weather. That could give the impression that the connection has "stalled".
I would have thought the change was worth trying, though it's really a sticking plaster solution rather than a proper fix.

[#14]

I got my Billion 7800n this morning and after setting up am connected at 1120 and SNR has remained in 5+ dB. A good leap from 928 and very low SNR. Will see how long it lasts !!