Comments on: Reader Find: The PC Cable Check Pro http://toolmonger.com/2007/01/04/reader-find-the-pc-cable-check-pro/ All tools. All the time. Your source for news, information, and reviews of hand tools, power tools, and tools of all kinds. Sat, 22 Nov 2008 17:39:48 +0000 http://wordpress.org/?v=2.6.1 By: Toolmonger » Blog Archive » Dealmonger: A PC Cable Tester For $30 http://toolmonger.com/2007/01/04/reader-find-the-pc-cable-check-pro/#comment-100559 Toolmonger » Blog Archive » Dealmonger: A PC Cable Tester For $30 Thu, 02 Aug 2007 15:11:20 +0000 http://toolmonger.com/2007/01/04/reader-find-the-pc-cable-check-pro/#comment-100559 [...] Back in January, we covered the Paladin PC Cable-Check Pro, an all-in-one gadget for testing the pinout and continuity of common computer cables.  But who’s got $130 for a cable tester?  Try this one for $30.  MCM Electronics is clearing out this discontinued Tenma-branded tester, which offers essentially the same features.  [...] [...] Back in January, we covered the Paladin PC Cable-Check Pro, an all-in-one gadget for testing the pinout and continuity of common computer cables.  But who’s got $130 for a cable tester?  Try this one for $30.  MCM Electronics is clearing out this discontinued Tenma-branded tester, which offers essentially the same features.  [...]

]]> By: Myself http://toolmonger.com/2007/01/04/reader-find-the-pc-cable-check-pro/#comment-11650 Myself Fri, 05 Jan 2007 13:05:15 +0000 http://toolmonger.com/2007/01/04/reader-find-the-pc-cable-check-pro/#comment-11650 I have a similar model, and it works great if you understand its limitations. To wit: This works by sending voltage on a single pin into one end of the cable, then letting the other end of the cable light up LEDs wherever the power comes out. It steps through the pins, so if everything is wired one-to-one, you see matching lights blink in sequence down the row. It's great for figuring out strangely pinned cables. Serial null modem and ethernet crossover cables are instantly identifiable by their blink pattern. As with the Behringer tester, you can mix and match cable ends: say you have a Cisco console adapter, just plug it into the DE9 jack on the left and the 8p8c jack on the right, and you'll see 1-nothing, 2-3, 3-6, 4-7, 5-4&5, 6-2, 7-8, 8-1. When I say "5-4&5", I mean that when pin 5 on the left side lights up, since it's bridged internally to pins 4 and 5 on the mod end, the lights for both pins 4 and 5 light up on the right side. However, as good as it is for figuring out weird pinouts, it's bad at finding intermittent faults, and can't do any sort of split-pair detection. Say you have a cable that goes flaky when you wiggle it. You plug it into the tester and wiggle it, but if the affected pin isn't lit up while you wiggle, you'll miss it, so you have to single-step through each pin and give a good workout each time. And even then, watching for a steady light to drop out for a few milliseconds isn't easy, so you're likely to miss it. Split pairs are a no-no when you're dealing with balanced signals of any kind, which expect to always run on twisted pairs. It's possible (and common!) to have a cable that's pinned correctly from end to end, but the right wires aren't twisted along its length. The cable looks good at DC, but when you put a high-frequency signal on it, you get all sorts of wacky crosstalk and interference. Since this tester operates at DC, it won't find those. Most affordable cable testers won't, actually. The cheapest I've found is the Test-Um "Testifier" TP350, which goes for around a hundred bucks. The TP500 is slightly cheaper (and it's the one I personally own) but it doesn't work with multiple-remote kits, which limits its usefulness on large jobs. I have a similar model, and it works great if you understand its limitations. To wit:

This works by sending voltage on a single pin into one end of the cable, then letting the other end of the cable light up LEDs wherever the power comes out. It steps through the pins, so if everything is wired one-to-one, you see matching lights blink in sequence down the row.

It’s great for figuring out strangely pinned cables. Serial null modem and ethernet crossover cables are instantly identifiable by their blink pattern. As with the Behringer tester, you can mix and match cable ends: say you have a Cisco console adapter, just plug it into the DE9 jack on the left and the 8p8c jack on the right, and you’ll see 1-nothing, 2-3, 3-6, 4-7, 5-4&5, 6-2, 7-8, 8-1. When I say “5-4&5″, I mean that when pin 5 on the left side lights up, since it’s bridged internally to pins 4 and 5 on the mod end, the lights for both pins 4 and 5 light up on the right side.

However, as good as it is for figuring out weird pinouts, it’s bad at finding intermittent faults, and can’t do any sort of split-pair detection.

Say you have a cable that goes flaky when you wiggle it. You plug it into the tester and wiggle it, but if the affected pin isn’t lit up while you wiggle, you’ll miss it, so you have to single-step through each pin and give a good workout each time. And even then, watching for a steady light to drop out for a few milliseconds isn’t easy, so you’re likely to miss it.

Split pairs are a no-no when you’re dealing with balanced signals of any kind, which expect to always run on twisted pairs. It’s possible (and common!) to have a cable that’s pinned correctly from end to end, but the right wires aren’t twisted along its length. The cable looks good at DC, but when you put a high-frequency signal on it, you get all sorts of wacky crosstalk and interference. Since this tester operates at DC, it won’t find those. Most affordable cable testers won’t, actually. The cheapest I’ve found is the Test-Um “Testifier” TP350, which goes for around a hundred bucks. The TP500 is slightly cheaper (and it’s the one I personally own) but it doesn’t work with multiple-remote kits, which limits its usefulness on large jobs.

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