The problem with a TDR is it's only good if you shorted or opened a cable. My problem has always been pair reversals on building cables and a TDR is useless for that. I have a Pentascanner that I used to use for this kind of thing and the only use I got out of it was discovering a split pair one time at a customer site that was left over from years earlier when someone had run voice on that cable. But keeping the battery packs working on the thing was a nuisance so I switched over to the $20 chinese pair scanner thing years ago.
It's also worth noting you can buy a TDR for $100 off Ebay. Chinese made of course. Ted -----Original Message----- From: PLUG <[email protected]> On Behalf Of Russell Senior Sent: Monday, January 29, 2024 10:16 AM To: Portland Linux/Unix Group <[email protected]> Subject: Re: [PLUG] Cable tester For years, we got away with a cheapo $20 continuity tester for checking Ethernet cables. The problem with them was that, yeah, sure, they would tell you if you had shorts or opens, but they did not tell you where. Cable itself tends to be pretty reliably connected end to end, but when you have crimped both ends and you find a short or open with a continuity tester, you have almost no idea which end you screwed up. You look very closely at the crimped ends, decide which one looks sketchier, cut it off and try again more carefully, then rinse and repeat. A few years ago, after suffering this problem for over a decade, we finally invested in a fluke microscanner2. It does time domain reflectometry, and can tell you, pair-by-pair, whether it has continuity and crucially, if it does not, how far down the wire the fault occurs. Suddenly, we know which end has the fault! If we stabbed the cable to death with hoop staples and there is a mid span fault, we know that. It cost us $500. It wasn't their fanciest model, but it has been such an improvement in reliability and visibility. -- Russell Senior [email protected] On Mon, Jan 29, 2024, 09:21 mo <[email protected]> wrote: > Hi. I need to buy a cat5 cable tester aka tone detector. There are so many! > How should I choose one? What features, brands, etc do you recommend? > > My bldg has up to 100' of cat5e I think. I'd like one I keep for > future use with different wiring (RJ11, cat6 7, etc). Idk what other > features to look for in such an item. I want to test for cable > quality, connectivity, speed, etc as well as locating which cable > terminates where (if all that's possible). 🙏🏾 >
