Over reading all this, my one line opinion is to agree with Chris. Cheers!!
On Oct 23, 2013, at 4:36 PM, Adam Thompson <[email protected]> wrote: > On 13-10-23 06:23 AM, chris kluka wrote: >> I guess my point is not that I distrust Metz... but that I don't understand >> your idea of "going off-roading". >> >> At the end of the day, you need a device to be inserted into another device >> which allows for mechanical and repeated connection of 8 connectors in an >> industry standard alignment and dimension. >> >> These connectors seem like gold plated HDMI cables to me... I don't see what >> benefit they serve over the 5 cent monoprice connectors in this purpose. > > Until you've disrupted national long-distance service by merely *touching* a > cable whose connector had slowly worked loose over the course of a few years, > it's difficult to internalize how important long-term reliability is for > connections made in the field. (FYI: *I* didn't make that cable!) > > It's not just a matter of experience, either - I've seen cables made by > highly-qualified, competent professional installers fail after two months in > use, taking down critical services. (This is a large part of why I'm > obsessed with pushing redundancy as far *down* the OSI stack as I can; > better-quality connectors are a way of making layer 1 more resilient... and > then I *still* deploy LACP!) > > I would, in fact, pay for gold-plated HDMI cables, if I had a suspicion that > they were going to be used for mission-critical applications, and would > remain in place for over a decade. > The gold-plating would, in that instance, be mostly immune to the gradual > corrosion all copper/brass/tin/silver contacts experience. > Gold is much less susceptible to galvanic corrosion - this can become an > issue since modern signalling levels are insufficient to exert any cathodic > protection. > I've seen a connector remain plugged in for years then suddenly fail due to > corrosion, presumably of the galvanic variety - no strain, no stress on the > cable, just slightly elevated humidity with moderate temperature swings, and > low-quality metal in the connector. (In that case, the corrosive pitting and > etching was actually visible under a magnifying glass!) > > Ironically, cables that are plugged and unplugged from time to time, although > suffering much greater mechanical strain, do not generally suffer from > corrosive effects. That very same mechanical strain on the contacts - > specifically, the scraping of the two sets of contacts across each other > during insertion & removal - generally eliminates any surface oxidization and > can even be enough to even out any pitting/etching. > > ILECs pay (or at least, they used to pay) what seems to be silly amounts of > money for top-grade cables and connectors, but I suggest they've just learned > from experience that trying to eke out additional savings on the cabling > and/or the connector isn't worth it in the long run. Heck, go into any > smaller or older telephone exchange, and you'll see bank upon bank of > *wire-wrap* termination! It's still in use not because telcos are resistant > to change (although they are!), it's because wire-wrap makes an electrically > and mechanically stable connection (even with lower-grade metals) that does > not degrade noticeably over time. Unfortunately, it also doesn't carry > high-frequency signals very well, so it's gradually being replaced with > punch-down blocks, which represent an acceptable compromise between bandwidth > and reliability. > > TTYL, > > -- > -Adam Thompson > [email protected] > Cell: +1 204 291-7950 > Fax: +1 204 489-6515 > > _______________________________________________ > SkullSpace Discuss Mailing List > Help: http://www.skullspace.ca/wiki/index.php/Mailing_List#Discuss > Archive: https://groups.google.com/group/skullspace-discuss-archive/ _______________________________________________ SkullSpace Discuss Mailing List Help: http://www.skullspace.ca/wiki/index.php/Mailing_List#Discuss Archive: https://groups.google.com/group/skullspace-discuss-archive/
