RJ11 Expansion card?

Hey, i just realized that an RJ11 should easily fit in an expansion card. There aren’t many options for connecting with RJ11 so I think it would be really cool if we could have that. Does anyone have any idea how we could make that work? Sometimes my connection goes out and I would like to have it as a backup option.

Thanks! I can’t wait to see what cards we can have!


Gigabit Ethernet uses all 8 wires in a standard Cat-5/e/6 RJ45-terminated cable, but 10-Base-T and 100-Base-T Ethernet actually only use 4 of the wires. RJ11 has 6 connectors, so I suppose you could make your own custom wired Ethernet cable: one end terminated in RJ45 for the network switch / wall plate and the other end for the laptop in RJ11. You should use twisted pair cable, as the straight cables you typically see terminated to RJ11 wouldn’t work well (the twists in the wire pairs prevent signal loss). I’m not sure about the mass market appeal of designing a custom network expansion card like this, but I bet some hobbyists / DIYers out there could pull this off if they really wanted to. I could definitely make the cable happen, but designing the expansion card is way above my skill level!

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Thanks for the reply! I meant rj11 for modem. Dialup is important because i have family without good dsl and poor cell service. They can still have dialup and it’s good for work emails. I would prefer not to have to carry a modem tho, thought the card would be good for it. Might have appeal to other countries too

So sorry - I totally misunderstood what you were looking for - building a Modem Expansion Card is a totally different path than the one I wandered down!

It’s all good! I’m loving the idea of trying to plug an RJ11 port into a gigabit network. The IT guy shows up and sees you with custom spliced wires and a bunch of adapters

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