GreatBlueHeron

The slab, the pipe, the Cat6 conduit, ground it all...

The Cat6 is not in conduit - it's direct burial rated cable. It was a bit of an afterthought - I already have a pair of Ubiquiti GigaBeams that are working very well. But, the trench was being dug for the water line so I jumped on Amazon and bought a cheap cable. I ran it my desk as a fly lead for a while to make sure it worked and then dropped it in the trench before it was back filled. If fixing my ground issues doesn't fix the ethernet performance I'll just go back to the GigaBeams.

..If I was in my line of work, there’ll be a 6mm² ground wire between both houses.

I might actually be able to achieve that - there's a 4 wire "well pump wire" from my new house back to the well, which is very close to the old house. One of those wires might be a ground and if so, it might make sense to ground it at both ends. I'll look into it.

No - the main comes down from above.

I turned the whole house off at the main breaker. I still have around 20V (it varies - sometimes it's as low as 14, I've seen it as high as 27) between my slab and the electrical ground. I also turned off my well pump, that's powered from another building, and it made no difference.

I was here for the build - I worked as a labourer for the main contractor. The electrical ground is bonded to ground with a pair of ground rods. But I am almost certain there is nothing bonding electrical ground to the slab. My slab sits on 2" of closed cell foam - so it is isolated from "actual" ground. As I re-read this before posting I'm remembering that there are bits of rebar puncturing the foam to (for example) anchor bits of plumbing during the concrete pour - so it's not really isolated. I'm confused.

I should add that I might have a bit of a complex grounding situation. I'm sharing a well and internet connection with my old house which is about 200' away on the same property. A brass fitting on the poly pipe bringing water into my new house is at the same potential as my slab - that is, 20V from electrical ground.

I'm using Cat6 copper to share the internet and am only getting 100Mbps on the link. I had tested the cable at 1Gbps before it was buried. I've been assuming the cable got damaged, but I'm now thinking it's related to my ground issues.

Again, I know there are too many unknowns for anyone to "solve" this for me, but I do appreciate the input and guidance. I'll be turning off and unplugging everything this morning to (hopefully) rule out a faulty appliance.

I prefer it the "Gulf of getting Associated Press to use it's correct name so I'll have an excuse to throw them out of the Whitehouse press pool". Maybe I'm turning into a conspiracy theorist?

I'm pretty sure that's the plan. I think there's even a name for it? Keep us so overloaded with fucked up news that we just zone out and let them carry on with their christo fascist nazi agenda.

I'm open to suggestions for what else I can do. I'm already not buying anything made in the US.

I get what you're saying but, as someone observing from outside, stuff like this is all I can do to resist.

I get what you're saying, but beware of the non-wifi devices that only operate through a proprietary gateway to a cloud-only service.

Facts, by definition, are devoid of context. They don't change depending on who states them! How can you have a reasonable conversation about anything at all if you can't agree on some baseline facts. That's how the fascists operate - everything the orange turd says is a fact, so you can't reason with them.