Having brought a new set of Devolo 500mbps Homeplugs recently I noticed they were interfering with the openreach modem and causing the SNR and Max attainable rate to drop.
Prior to the Homeplugs I was getting SNR 6db with a Max attainable around 61mb and sync rate of 52down
After installing the new homeplugs i noticed my SNR dropped a little bit and Max attainable dropped to about 57mb down and sync rate of 49mb.
When the homeplugs actively transmitted to each other the SNR would plummet I have seen it as low as 3.5db.
I have since installed a mains filter and ferrite beads to the cables into the modem which restored my SNR, Max attainable and sync to what they were previously however again when the homeplugs transmitted the SNR and MAx attainable still plummet although the Huawei openreach modem is brilliant at maintaining sync even with loads of extra interference so my Sync and download rate never dropped even when homeplugs were in use.
This is where my £5 purchase came in and far surpassed my expectations, I purchased a new RJ11 modem cable. It is a cat5e shielded standard and it really looks like a well made piece of kit.
I plugged this cable in and BAM!! SNR is still 6 however my Max attainable is now 65mb and my sync rate is now 56.2mb down, this is the fastest i have ever had my connection and its all down to a small piece of cable, I'm amazed!
Now it doesnt solve the problem with SNR plummeting when homeplugs are in full transfer mode however due to Max attainable being being higher the lowest I have seen this drop to when homeplugs are transferring is 59mb which is almost as fast as i used to get before the homeplugs.
When the homeplugs are in standby they are very quiet and dont really introduce much interference so can be left on with no fuss.
As the modem is brilliant at holding onto a sync with a low SNR i have never had the connection drop even with the homeplugs in full transfer mode.
So after £42 on a mains filter and £6 on ferrite beads it was a £5 1meter RJ11 cable that had the most effect and i would highly reccomend this to anyone especially those on longer loops or like me have their modem near lots of other electrical stuff.
For those interested in purchasing said cable go onto tandyonline .co.uk and search for "High Speed RJ11 DSL cable"
(cannot post links to shops on this forum) they do the cable in various lengths from 0.5 - 20meters and it is made by a company called ADSL Nation.
Nice heads up mate! I've been after a 0.5m RJ11 to replace my existing 1m cable (anything to reduce cable clutter!) and can't really turn my nose up @ £2.99. Hardly any more expensive than the cheapest going on eBay and who knows what you're buying half the time on there!
Excellent, I might try it. I bought some cheap ethernet cable with RJ11 connectors on eBay: worse performance than the cable provided with the Openreach modem.
On the Powerline side ... Somebody else posted that Powerlines worked better if not plugged into half a twin socket, with computer equipment in the other half. I didn't believe it, but tried moving things around anyway, and the post was right. In my case neither end was near the modem, so the broadband itself was not affected. It was just the speed over the powerlines that changed (both the speed mentioned by the Zyxel utility, and the speed measured using NetSpeed).
Unfortunately I can't find all my original test results, but I think they went from 35/50 Mbps in the two directions to around 80Mbps in each direction. Well below the rated 500Mbps.
My 500mpbs homeplugs are connected at around 350mbps to each other, sometimes it drops to 300 othertimes its been as high as 420mbps, one is plugged in near the TV and all the home cinema stuff which is also where the modem is as well hence the SNR drop when transferring data over powerline, the other is in the upstairs bedroom for the Sky+HD multiroom box. Unfortunately with a 2 year old who likes wires i am limited in where the downstairs one can go, hence why it is hidden behind the TV stand with all the other plugs.
If you have an unlocked HG612 openreach modem, go onto the stats page and then force a transfer over the powerlines and see if your SNR and max attainable drop when using them.
But back on topic for a fiver you have nothing to loose, at worst it wont give you any increase at all, at best you can get a decent speed increase in my case 4mb, although upstream hasnt changed in the slightest but saying that it wasnt affected by the homeplugs either just the downstream.
Folks you might be interested in this table that I producted from actually testing the different types of "powerline" (Home Plug) adapters -
Product Technology Maximum Link Rate (Mbps) Typical Actual Throughput (Mbps)
HomePlug 1.0 14 5
HomePlug 1.0 w/ Turbo 85 10-20
HomePlug AV 200 40
DS2 / UPA 200 -
HomePlug AV 500 500 70 -80
I couldn't test the DS2 /UPA standard devices as I didn't have any.
This testing was in a controlled environment as well - we also injected noise in the power system as well so some people might get better and other worse.
Different generations of "home plug" (Powerline adapter) don't play nicely together so beware.
Powerline in general will work across multiple phases and circuits within a building as well - especially the latest generation. They work on both conducted and radiated signals.
Hope this all helps
For those who do try this cable post your results here as I would love to see if everyone has the same experience as me, I doubt people close to the cab will notice any difference as they already sync at top speed but I imagine people on longer lines like me may notice something.
If enough people post good results on this thread it will be a good thread to help people with slow speeds.
hi stuey, i was going to get the cable you suggest but as the cab is only 2 doors away i dont think it would make any difference as i am getting pretty much the max i can get, but thanks for the info, i love to learn new things
Well my 0.5m RJ11 arrived today. Replaced the cheap 1m eBay cable I had hooked up and, though I'm unable to go confirm the full sync stats as I haven't unlocked my OR modem, after running the BT Speedtest my IP Profile has increased ever so slightly from around 77.30mb to 77.43mb.
Nothing to shout about obviously but I believe 77.43mb remains to be the max IP Profile on 80/20 (happy to be told otherwise) and this is the first time my IP has been 77.43mb since my Infinity 2 was activated on the actual launch date back in April last year.
The download test result came out at 75.13mb which is also the highest I have seen in a very long time so maybe the proof is in the pudding!