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
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