Wonder if anybody know there is a DIY Network Cable Tester out there, something similar to these testers
eBay auction: #261822600212
eBay auction: #252711580056
eBay auction: #292500127300
I have a slightly earlier revision of these (actually I have 2, the first was DOA so they sent a new one and while that was arriving I replaced the broken 0805 resistor in the first). They are actually really quite good.
Do a good job at making clear you've crossed a wire, the TDR is great for fault finding as it gives you a good indicator as to how far away the fault is (my end of the cable or the far end?) and the little squeaker in the remote dongle makes identifying pretty easy. Actually, the TDR has come in handy heaps. Need to replace a cable in an unknown/undocumented pit system? Just whack this across it and get a length estimate to see if you have enough in the van or need a bigger drum.
The built in F-set does a credible job too. I paid about $35USD for mine. The local electronics shop has the same thing listed for a couple of hundred bucks. It's not worth that though.
I do wish I'd bought the one with 8 dongles though. Maybe next time. Recommend A++ would buy again.