Use a 2nd. router as a wifi extender

[#1]

My son's house has very thick stone walls and he is struggling with his wi-fi in one of his rooms.

He uses his phone and a bluetooth speaker in this room and the signal is a problem.

He has some TP Link powerline units and I have a couple of spare routers, a Netgear DG834G v2, and a Technicolor TG582n..

If he connects the primary router, a Sagemcom 2704N to a powerline plug could he connect the extra router to a another powerline plug in the problem room and use it to extend his wifi range?

He's tried a wireless repeater but had the usual problem of things failing to connect to the network.

[#2]

I don't know about the Technicolour but I have converted a DG834GT to do this. However it can't be just plugged in, it first needs to be set up as a wireless access point.. This is not difficult. If you do an online search you will find instructions but if you get stuck come back here.

[#3]

One further thought and maybe worth a try. If the wireless repeater has an Ethernet port just see if it will work in reverse. That is, plug an Ethernet cable from the remote powerline unit into the Ethernet port on the repeater and see if it will work in reverse. I have done this successfully in the past with both Devolo and TPLink powerline wireless units, using just one as a wireless access point fed from an Ethernet cable but have no idea if it would work on an extender.

It ain't going to break anything and if it costs nothing to try...

[#4]

Thanks for your response. It will be next week before I can try anything.

[#5]

Many powerline units transmit a wireless signal at the far end so a second router would be superfluous (e.g. https://www.johnlewis.com/tp-link-300mbps-av600-powerline-extender-starter-wi-fi-kit-tl-wpa4220-kit-... ).  Otherwise a router configured as an Access Point (connected as you suggest) would do the job.