Reddit reviews Netgear PE102 10MBPS(10BASE-T) Home Phoneline RJ11 Ethernet RJ45 Bridge
We found 3 Reddit comments about Netgear PE102 10MBPS(10BASE-T) Home Phoneline RJ11 Ethernet RJ45 Bridge. Here are the top ones, ranked by their Reddit score.
You can try those power-line ethernet adapters. Personally, I have had very mixed results. Sometimes they worked great, other times total crap. I would unplug the two that I had from the wall at one apartment (where they worked great), and take them to my next apartment where they "worked" slightly less well than a 9600 baud modem on a noisy phone line.^1
On a similar note, if there's a phone jack both upstairs and downstairs you can try and use those ethernet-to-phoneline bridges - for example.
But both of those require spending money, which it sounds like you're loathe to do.
Are you sure you can't run an ethernet cable upstairs? Even just running loose up the stairs? (I assume you're not willing to drill holes in the walls because it's a rental.)
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^1 Whelp, I just showed how old I am. GIT OFF MAH LAWN!!
It's technically possible, but it would be much easier, faster, more reliable, and cheaper to just buy a long enough Cat 6 cable.
Over 2-pair, sure... because you still have 8 wires at that point. However, over a single RJ-11 port, you'd only have 4, which aren't enough.
You'd need something like this in order to make it work: https://www.amazon.com/Netgear-10MBPS-10BASE-T-Phoneline-Ethernet/dp/B00005AYMC (provided you have dual RJ-11 ports to work with)