Thicknet/10base5 Test Segment: The Cable is In!

[Peter Coghlan]

On 2018-06-27 19:34:38 -07:00, Chuck Guzis via cctalk wrote:
> On 06/27/2018 04:19 PM, Antonio Carlini via cctalk wrote:
>
> > No idea. But on thickwire the taps were all supposed to be made at
> > specifically marked positions (for the reason given earlier).
> > Perhaps someone (incorrectly) thought that the terminator should also be
> > at such a position and so a terminator could not be located at a tap?
> 
> It had occurred to me to wonder if some poor tech had measured out, say,
> 151 meters of cable where 152.5 was called for by the "exactly every
> 2.5M spec).  It would seem that any attempt to add an extra 1.5 was
> believed to be called for in order to install a terminator would have
> resulted in a "cure" worse than simple adding the terminator at the end
> of the cable.
>

I guess one of the keys to a successful networking technology is that it
should be possible to specify how to install it in a way that people not
familiar with the inner workings of the technology can readily deal with.
There are advantages to keeping the instructions as simple, short and easy
to follow as possible with a minimum of exceptions and special cases.

It might make sense to state that everything should be spaced 2.5m apart
even when there is no advantage to this in the special case of terminators.
The advantage is in reducing the complexity of the instructions.  The
disadvantage is it might lead to difficult cases like this one.

On a slightly different point, didn't the thickwire spec call for the outer
conductor of the cable to be earthed at exactly one point, presumably for
safety reasons in case the cable contacted something at high voltage?
This requirement was somehow not carried forward into thinwire, perhaps
because the entirity of a thinwire network, including the connectors was
supposed to be insulated and therefore not a danger to anyone?  DEC produced
insulated thinwire connectors and terminators but other than that I think
this requirement was honoured more in the breach.

Regards,
Peter Coghlan.