Replying to myself to ask a supplementary question.

Can the Powerline adapter feed a hub to enable >1 PC or the like to connect wired to the network?

I needed to connect a smart TV which didn't have built in WiFi and running Ethernet across 2 rooms was more than I could face. I bought a Trendnet AC1200 Wireless Media Bridge (from BT, for what it's worth). This takes a WiFi input and outputs up to 4 ethernet cables and I found it worked perfectly even with a badly placed router and 2 intervening concrete block walls. Only problem was set-up - WPS didn't work so I had to plug it in to the router to set up, then all ok.

In reply to a post by cheshire_man:

I remembered this morning that I had a couple of old Comtrend Powerline adapters that I'd been given...

...So I'll take them and some network cables this evening and see what's what. They have a power pass through socket so there's no need for spare sockets. Just have to persuade the couple not to switch them off.

Took them, installed them, worked first time straight away.

So if they continue to work in a week or three, I'll see about getting and installing some more permanent arrangement. Such an arrangement will need to be able to connect by Ethernet both PCs to the router. Clearly the potential for the currently Win 7 PC to fail wirelessly as and when it's upgraded to Win 10, has to be borne in mind.

So any recommendations for PL devices? Preferably ones with pass-through power, and the ability to network two PCs.

There appears to be reports of some TP Link PL devices dropping out, not sure how widely that occurs. Certainly don't want a situation where the PLAs need to be power-cycled or reset from time to time.

An update.

Was over there last night - they make excellent coffee!

The Powerline Adapter has worked flawlessly for a few weeks now so looking to implement them for both PCs.

Their desire is to use separate ones for each PC, so a single Ethernet post per adapter is fine, they can spare the necessary power sockets so pass trough power is not needed - and makes the adapters bulkier Speed is irrelevant, their BB is only around 3-4 Mbps.So need a total of 3 PLAs, 1 for router, 1 for each of 2 desktop PCs.

This TP-Link AV500 (TL-PA4010KIT) looks to be good value and suitable. Given we'll need 3 of the units it would be simplest to buy 2 sets, which gives a degree of resilience, just in case.

I assume that you can have 3 of these talking amongst themselves?

In reply to a post by cheshire_man:

I assume that you can have 3 of these talking amongst themselves?

Yes you can

Would be worth checking that the Win 10 USB powersave hasn't defaulted to 'On' for the WiFi dongle...
Best done through the 'traditional' device manager rather than the hobbled Win 10 settings menu's

It hasn't. As soon as I go and reset the dongle software it works perfectly, then it randomly days or weeks later drops out. I've checked all the settings, time-outs, etc. I'm not wasting my time trying to keep wireless working when when there is already a working wired solution.

I've said that it is not staying wireless, they're desktop PCs and wired is the way to go and it's been working perfectly for several weeks via the PLAs.

Another PLA question.

For the current setup the one that is connected to the router is plugged into an extension board, the PC-connected one is direct into a wall socket.

However I read that PLAs must/should (not sure which) be connected direct to a wall socket. Why?

Is it a speed issue, or reliability, or what?

Generally both, extension cables can be of variable quality, cable cross sectional area and don't always have great connections - additionally, they can be coiled up or snaked across other cables which can cause degredation of the data signal - generally, mains house wiring doesn't have so much 'variability' as extension cables, i'd also avoid using on the output side of filtered sockets or extensions as these are designed to remove 'noise' (data over mains would be seen as noise) from the mains supply. Finally, some home-made extension cables i've seen are only two core, which wouldn't help either for data or electrical safety!

You said earlier in the thread they didn't need ones with power pass through because there were plenty of sockets. If they are being plugged into an extension lead then there aren't enough wall sockets so this is where you can use a pass through adapter and plug the extension into that.