[Elecraft] W-2 Cable Question

[Jack Brindle]

The cable carries 5V power to the sensors. There are 6 analog signals (three for FWD per, three reflected) coming back, and, of course, ground to make up 8 signals.
The sensors have op-amps to be able to properly handle for very low-power signals, something that makes the W2 rather unique. The sensor diodes are biased to make sure they always operate in the linear region.
It just may be one of the best devices available for low-power signals.

Power and ground each have a single wire.

Elecraft is a very cost-conscience company (as are most these days). If the purchasing folks can get CAT cables for less money than the flat cables, then they will do what makes sense.

73,
Jack, W6FB


> On May 15, 2025, at 10:55 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> On 5/15/2025 7:10 PM, Jack Brindle via Elecraft wrote:
>> The W2 uses the eight wires for individual signals, unlike ethernet. But, at the low analog signaling it uses, there really is no reason not to use a short ethernet patch cable.
> 
> Hi Jack,
> 
> What's the form of signal on those 8 conductors? Power, DC from sensors, or RF? If data, which conductors carry that data?
> 
> Jack knows this, for for those reading the mail, structured cable like CAT5 and later versions consists of four transmission lines, with each pair having a different twist-ratio (in cable mfr world, called the "lay") to minimize crosstalk between pairs.
> 
> Because they're twisted pairs and because their twist ratios are fairly high, they have FAR greater rejection of noise and other signals than ribbon cable, and I suspect that they also have greater bandwidth. But to function as a transmission line, they must be wired as transmission lines.
> 
> And if that ribbon cable is carrying DC, it may have larger gauge conductors, for lower loss at DC.
> 
> 73, Jim K9YC
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