Are these Chinese ethernet/coax testers any good?

[dorkshoei]

https://www.aliexpress.com/item/2044442346.html

I can't imagine the coax portion would be useful here in the USA as cable-tv is RG6/RG59 75 ohms.

I couldn't see a combined ethernet+RG6 tester on AliExpress.  Just ethernet+bnc.

[CJay]

It's not going to measure cable impedance, it's just a basic continuity tester so it'll work just fine on 75, 93, 25 or whatever impedance coax as long as you stick a terminator resistor across the end of the cable.

[dorkshoei]

In the listing there is an image where it's showing impedance.

[JohnnyMalaria]

It's not intended for CATV etc. It's meant for networking.

Here's the manual (with different branding): https://sgcdn.startech.com/005329/media/sets/REMOTETEST_Manual/REMOTETEST.pdf

[CJay]

In the listing there is an image where it's showing impedance.

No, there isn't, there's an image where it shows you it can tell if there's a terminator attached.

It's measuring terminator impedance (and probably only well enough to tell if it's got one or two terminators attached) not cable impedance.

[radiolistener]

In the listing there is an image where it's showing impedance.

This is not display This is just a sticker with label near led.

[ralphrmartin]

Going off beam a little, I got one of these for testing my PoE Ethernet, and it seems to work OK for the price.
https://www.aliexpress.com/item/1005001737031111.html

Can't comment on coax as my only piece of coax runs up to the roof where I can't get at it anyway.