Ethernet cable (Was: Sun3 valuations?)

Al Kossow aek at
Tue Jan 23 18:04:52 CST 2018

On 1/23/18 12:27 PM, Paul Koning via cctalk wrote:

>> The stuff with better shield, marking bands, etc is 10 Mb; it's about 1.05cm
>> in diagmeter. The black stuff (the stuff Dave is holding in the video) is 3Mb;
>> the piece I have is .95 cm.
> The Ethernet spec says that the cable OD is in the range .365 to .415 inch, which is 9.27 to 10.54 mm.  The nominal OD of RG-8/U is .405 inches, or 10.28 mm, which is within spec for Ethernet cable.

He's holding up the wrong stuff if it's RG-8

Experimental Ethernet is 75 ohms.


Drive Voltage: +3 volts (Nominal) into  >> 37.5 ohms <<

There is a clue in the PARC Ethernet Blue and White about this where they mention they used CATV technology
(where the vampire taps come from ) but they don't actually say there that they used 75 Ohm cable, terminated at both ends.

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