On 2/1/2012 3:07 PM, Stuart Rohre wrote:
> Be cautious about grounding a non grounded audio output, like a phone
> jack or spearker output. It may be intentionally floated as a balanced
> output circuit.
Hang on a minute -- we're not talking about an OUTPUT, we're talking
about an INPUT. And, NOT bonding ANY cable shield to the chassis is the
#1 cause of RFI in ALL equipment, including ham gear.
Note that I speak with some authority on this -- I'm Vice-Chair of the
EMC Working Group of the Audio Engineering Society Standards Committee
that WROTE the Standard for solving the Pin One Problem, and have
published considerable research showing that Pin One Problems are the
primary cause of RFI in almost all gear. That Working Group also
includes engineers from ABC-TV, the BBC, Dolby Labs, and Lucasfilm.
Henry Ott, who literally wrote the book on EMC, is also a member of the
WG. Neil Muncy, ex-W3WJI, who published the first work on the Pin One
Problem in 1994, and I were both elected Fellows of the AES, partly on
the basis of that work.
73, Jim Brown K9YC
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