RE: Re: TV audio onto HiFi via Kat5?

[Keith Doxey]

<VICTOR MELDREW>
I DON'T BELIEVE IT !!!!
</VICTOR MELDREW>

NO other manufacturer (to my knowledge) has found it neccessary to adopt
non-standard wiring for CAT5.

The bullet point about avoiding Power/RF is good wiring practice but one of
my tests was to deliberately run a long length of CAT5 adjacent to a 3phase
mains cable about 50mm diameter dropping 4 floors in a cable riser. There
was absolutely no interference detected on the VGA picture some 185m from
the PC.

The bullet point about ground loops has me confused. The WHOLE point of
Balanced Transmission is that neither end is using ground as a reference
therefore ground loops become non-existant. If you have a source of
interference that is so great that screened cable becomes neccesary, I
would
be looking to erradicate the interference at source.

You had also better be prepared for some pretty major rewiring, they seem
to
be advocating replacing your existing Ring Main with Radial power circuits
run from a central point!

As if the non-standard pin assignment wasnt bad enough, the two ends are
wired as opposites. I assume they sell suitable ready made patch cables and
would hazard a guess that a 3m lead would cost slightly more than the £1-75
that I pay (1 off) for my patch leads (£0-92 for 100 off).

4mA Current Loop modern variation on the older 60mA and 20mA transmission
standard that were used to provide robust communications in an electrically
hostile environment prior to the existance of RS485. RS485 is widely used
in
industry for all types of industrial control without any problems.

I think the wiring standard adopted is crazy and can only cause confusion,
especially if someone buys a modern luxury home that is precabled with CAT5
as they will then be faced with their installer "modifying" the
wiring in
the home. It will be worse if the homeowner already owned the Knect system
and thought they could just "plug'n'play" in the new house.

Keith



-----Original Message-----
From: Nick Towers [mailto:<a
href="/group/kat5-users/post?postID=QIzCyDbMHh6fl3ylL0kimOkmqUrMIk2PAT7h-EzrnB7_SovwkcT3Ykw-tQdkSzRLMfALnNxzvVsrsaw">nickt@t...</a>]
Sent: 09 October 2001 15:43
To: <a
href="/group/kat5-users/post?postID=sLclsSY4MBdgWk7shfg8yuzFgBjLhJBRgkniYAJ6zLH3sSS-v_3Al-0F2Z0XAdbVZY8_XyZnHpGgamsvE9Kczus">kat5-users@xxxxxxx</a>
Subject: RE: [KAT5] Re: TV audio onto HiFi via Kat5?


Attached is the info I got from Linn on their wiring - it may be of
interest. Nothing like making things more complicated than they need to be
though! They're also into their screened cable in a big way (which I
suspect
gives limited benefit)! Also had the following addendum (fair enough I
suppose..) "Our engineer has advised me to highlight that Pins 1 and
4, 5
and 8 use a 4mA current loop. Please be aware that any damage caused due to
interfacing non-Linn products to these inputs will not be covered by
warranty."
I expect the current loop provides the Linn to Linn control (I cannot
imagine this being anything but a minefield, so I'll steer well clear.)