On Wed, 29 Apr 2015 17:41:02 +0100, News wrote:

We use homeplugs (yeah, I know) ...
snip
I suppose I could buy a long CAT5 cable and connect his desktop directly
to router?

Is the right answer and for the feed to the AP in the kitchen. If
that is a WiFi Homeplug bin it and get a cheap AP. Aldi have (had..)
Miginon WLR-510 AP/Repeater/Client 2.4 and 5 GHz 802.11 a/bg/n "up
to" 300 Mbps plug top device marked down to £14. Or Tesco have
TP-Link TL-WR841N 2.4 GHz only AP/Router for £20. The TP-Link will
probably do a little better for range as it has external (but non
removeable) aerials but if you are in the same room as it that's
unlikely to be noticeable.

Wouldn't be at all surprised if the crap being put onto the mains
wiring and radiated from it is getting into the VDSL and stopping
that running at it's best as well.

--
Cheers
Dave.