Re: USB cable quality and QRM in a spyserver setup with an Airspy Hf+ and Raspberry PI3. 6 microUSB cable test. #airspyhfplus #bestpractice #raspberrypi

Dana Myers
 

On 3/13/2018 9:32 PM, Ian DXer wrote:
Hi Dana,

Pleasing to read your report on your success with the Volutz USB cables.
Thank you.


I was looking at the Volutz Facebook page & I note that Volutz have just released a new Apple Lighting Cable.
For noise immunity I like the metal shroud that links the foil shield of the cable & surrounds the connector & components
underneath. One also gets a better look at the dual cable shielding from the drawing on the Facebook page.
Are these SMD components part of the lightning spec or are they part of Volutz's attention to EMI/EMC or impedance
matching?
I do not know anything really about Lightning (the only Lightning cables in
my house are associated with my wife's iPhone).

I see a similar shroud on their USB C cable from their Facebook page.
What's not clear to me is if Volutz use a metal shroud on their connectors for their USB 2.0 to micro USB cables or
any filtering SMD components (if that's what they are?) similar to their new Apple Lightning Cable.
The Volutz website is scant with close up pics & tech data.
I do not know the details; I just know I found one graphic that says the power
lines in the USB cable are 22 AWG :-)
A further improvement to their USB 2.0 to micro usb cables would be to have a foil shield between the data & power pairs.
Perhaps, but what are you seeking to address with this? The data lines are a
differential pair and surely twisted (but I don't know for a fact). Given that the
data lines are very low current, I'd be surprised if they induce meaningful noise
into the power lines. On the other hand, I'd expect noise from the power lines
to be induced as common-mode into the data lines and thus disappear from
the data.

73,
Dana  K6JQ

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