Home Plugs lowering SNR margin

I have discovered that when using the BT supplied Home Plugs that when a device is attached to them and downloading a file that the SNR margin drops from around 5.5 to 3.5 on my unlocked HG612. As soon as the download stops, the SNR goes back up again.

Have tried all kinds of different physical setups (cables types, proximity to HG612, different power points, etc etc) but it makes no difference.

Anyone come across this and found a solution other than replacing them with a length of cat5 cable instead!?

not surprised, they operate in similar (same ?) frequencies and mains wiring isn't exactly twisted pair and shielded as the amateur radio community are keen to point out.

Don't know if ferrites on the router power cable would help

I think the jump to profile 17a has meant that there can be conflicts now, have not had FTTC available to me to actually play and assess the impact.

It may be a case of people having to balance the pro and con, but Ethernet is still the king and still cheaper.

If it really is caused by the HomePlug signal causing interference on the modem, you could try using an RF filter like the Tacima 6 Way Mains Conditioner. I've seen suggestions that this suppresses the HomePlug signal pretty effectively, so could be a solution.

Ferrites didn't help in my case, I had lots of issues until I replaced the Homeplugs with cat5,

Impact on mine was about 4Mb/s, and I'm > 1Km from the cab, so a big impact.

I must do some measuring - however the power for my Modems and routers (as well as the computers and screen) is supplied via a UPS - so that may filter out the effect of the Powerline signal.

I only saw a 0.1dB drop in SNR margin when I was downloading. I'm using Solwise NET-PL-500AV plugs and the one downstairs is right next to the master socket with the modem a couple of feet above.

I still dont understand why people to go all measures to avoid using ethernet cables. to the OP spend a few £ get some long cable and install it.

In reply to a post by DRW:

I must do some measuring - however the power for my Modems and routers (as well as the computers and screen) is supplied via a UPS - so that may filter out the effect of the Powerline signal.

Depends on what type of UPS you have.

Chrysalis
I use Home Plugs because to install an ethernet cable tidily would involve lifting carpets and floor boards and drilling through walls. Of course I could just tack it round the skirting and up the stairs but then you haven't met my wife!

I use homeplugs because my landlord won't let me cable up the house.

Because it is a pain. I ideally want the router in my study, but would have to run 20m or so of Cat 5 and would have to drill and drag through walls as it is unsightly to tack around the skirting board.

So the router stays in the room with the master socket and homeplug to my study. I still get 74mb/down though

I just put it alongside base of wall, and it has to go across my hallway, I put a mat over it in the hallway. In the living room where my phone line is as well as my gigabit router, its behind furniture hugging the wall.

Its doable if motivated enough, shouldnt need to put under carpets to keep tidy. Granted tho I dont have anyone living with me to moan about it

If its on a different floor I would consider putting up the outside wall, I did that at a previous address and rain snow etc. never affected it.

I've cabled up my entire house as I've renovated it, it's a major job even when renovating a house, whilst living in it at the same time with my family.

I do still have one cable running externally, it's been there about ten years and is still OK. The new cable is run from the server room but it is sat in a coil behind the settee ready to run around to the TV/media centre but just haven't finished it yet.

We also have what must be 60 meters run outside at work, been there over ten years as well, and it's only normal cat5e cable and runs fine as far as I know - it feeds my office, at 1Gbps

Well I have now "binned" the home plugs and will hard wire, just waiting for the cable to arrive. Since they have been disconnected my CRC's have only gone up a couple, normally they would be a couple of thousand in a day. The biggest significance is the FEC's which have gone from about 2,000,000 every 15 minutes to 1500!!!

Pretty dam conclusive, in my case at least, that home plugs should not be used on Infinity based systems!

Thanks for all the replies.

Edited by dgilbert2 (Sat 02-Feb-13 18:40:25)

Your results are in line with another recent thread. You're better off without the Homeplugs.

good job you may well have also been affecting neighbours as well.

The day it took me to dig the trench, lay the kopex and back-fill?

If I'd have tried to run it through the house it would have taken longer and ended in divorce.

Another pleasant surprise today around 2-3 days after removing the home plugs

The modem re-synched this morning and now Interleave has been removed and the sync speed up from 53MB to 57MB.

CRC's now around 1000 a day. Last time I was on FAST, CRC's were up at 300,000 a day!

Best decision yet to buy some cat5 cable and bin the home plugs! No wonder BT say for Vision Essential Extra you cannot use home plugs.

In reply to a post by dgilbert2:

Another pleasant surprise today around 2-3 days after removing the home plugs

I've used homeplugs for years (early Devolo, 80Mbps?) and never had any bother with them, but my line occasionally switches between interleaved (~61Mbps) and fastpath (~67Mbps) and that post prodded me into having a look at my wiring...

I realised that the cable from the master socket to the modem (bog-standard flat twin) was actually laying on a homeplug... so I replaced it with a more sensibly routed length of Cat5.

After re-sync a speed test showed another 3Mbps . Could be coincidence of course, it'll be interesting to see if I get fastpath back in a few days.

Interesting. I have only recently had home plugs and see no adverse effect. My set-up: (All cat 6 cable)

bt modem --> Cat 6 cable to Sky router LAN port 1

LAN port 2 --> Home plug (in a surge protected extension socket) --> home plug upstairs --> Sky box (multiroom)

LAN port 3 --> back of my pc a few feet away.

I have not seen a decrease in speed since buying them. Are you people (who do have problems) plugging the BT HG612 direct into the home plug then passing the connection along to the router / pc?

In reply to a post by Angel_Rex:

Are you people (who do have problems) plugging the BT HG612 direct into the home plug then passing the connection along to the router / pc?

Not in my case, it's basically not dissimilar to your layout.

The modem Ethernet port goes straight to the WAN port on the router and one of its LAN ports feeds a homeplug (direct into a mains socket, not via an extension lead) to run an A3 printer in another room (it's a bit big for the room where the computer lives).

The modem, router and iMac are also fed from a UPS which should stop any mains-borne interference from the homeplug.

If it does turn out to have been the reason for my fastpath/interleaved changes then it's almost certainly due to the modem (VDSL) lead being in far too close proximity to the homeplug... The wiring topology is fine, but the physical cable layout probably suffered from a moment's inattention last time I tidied up the rat's nest, which was longer ago than I'm comfortable thinking about .

Edited by billford (Wed 06-Feb-13 13:58:03)