On 2/28/2019 3:36 PM, Gedas wrote:
We had an issue with a product during some specialized radiated tests.
Tasked with the investigation I found that the item was using shielded
USB cables, as expected, the only problem was the maker of the cables
(a large company that starts with an L and ends with a com) was not
terminating the cable shield in any way.
AAARGH!
What was more disturbing to me was that I had to explain to two of
their engineers that the shield had to be properly terminated to do
any good. Just because it has a shield or braid around the conductors
means absolutely nothing.
DOUBLE AAARGH! Far too many hams don't realize this either!
And the sad part is that you have to at least scrape the jacket and use
an Ohmeter to figure this out!
For decades, el-cheapo audio cables have been made with a wire as the
return rather than a shield.
73, Jim K9YC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|