Cat5 cable certifiers, NEXT/FEXT/attenuation measurements. Anyone?  - Page 1
Forum section: electronics / testgear

author: Myself
author_rank: Contributor
timestamp: April 21, 2019, 12:58:44 pm
content: I got into a discussion recently about whether pair untwist matters (that's easy to prove empirically with iperf and some scrap cables), but moreover, how much untwist you need for it to be detectable.Back in the late 90s, I was a professional drop-ceiling molester, throwing cat-5 into any building that would hold still long enough. We had a set of Wavetek certifiers that had to check every run before we could call the job complete. I figure, if anything's actually gonna measure the effects of cable termination technique, these would!They were unconscionably expensive at the time (I remember being told they were comparable to the price of a small car), and weirdly enough, when I look 'em up on the used market now, they're still remarkably pricey. Most of the other test gear I used at that time (DS3 to OC48) has dropped 99.9% in price, but the Cat5 certifiers have only dropped about 90%...Doable, but not pocket-change for a bar-bet "I can make a better cable than you can" sort of thing.Does anyone have a set of these, and if so, do you use them? Got any recommendations, either preference or avoidance of certain models?

author: David Hess
author_rank: Super Contributor
timestamp: April 21, 2019, 06:29:58 pm
content: If you want something inexpensive, some Gigabit Ethernet adapters can perform the basic tests through their driver or a utility. Some Gigabit Ethernet network switches might also.

author: ogden
author_rank: Super Contributor
timestamp: April 21, 2019, 07:25:43 pm
content: Quote from: Myself on April 21, 2019, 12:58:44 pmThat's because oldskool circuits like DS3, OC48 and similar are phased out and telcos are moving to .... (surprise surprise) Ethernet/MPLS.QuoteDefault "go to" is Fluke CableAnalyzer. There are some other good lower cost alternative certifiers. Fluke just works out of the box and it's reports are accepted w/o hesitation. #1 suggestion: Before you buy certifier - know it's Ethernet socket servicing options/price/time, account for such as well. Sockets wear out or just get damaged by improper use. Obviously train your technicians well.Quote from: David Hess on April 21, 2019, 06:29:58 pmEthernet tester does continuity tests and maybe TDR cable length while certifier does full frequency sweep measurements for attenuation, crosstalk and more. You just suggested multimeter for someone who needs scalar network analyzer

author: David Hess
author_rank: Super Contributor
timestamp: April 21, 2019, 08:18:25 pm
content: Quote from: ogden on April 21, 2019, 07:25:43 pmNo, some of them return attenuation and other characteristics measured in dB. I recall seeing this on a Marvell or maybe Intel based adapter.

author: ogden
author_rank: Super Contributor
timestamp: April 21, 2019, 08:33:40 pm
content: Quote from: David Hess on April 21, 2019, 08:18:25 pmAre you sure? Let's do it this way: I provide fluke screen (attach) which shows what I am talking about, you provide Marvell or maybe Intel adapter report which shows what you are talking about.

author: David Hess
author_rank: Super Contributor
timestamp: April 21, 2019, 10:05:35 pm
content: Quote from: ogden on April 21, 2019, 08:33:40 pmI was sure that I ran across one which reported near and far end crosstalk but it looks like I confused it with the advanced diagnostics (TDR, short, open) provided by some Intel, Marvell, and Broadcom Ethernet ASICs.