On 12/15/2010 10:16 AM, Dr. Gerald N. Johnson wrote:
How about checking the control board grounding, as well as the cable
shield grounding?
Yes, cable shield connection (NOT GROUNDING) is quite important. It MUST
go to the shielding enclosure on both ends. DO NOT CONNECT CABLE
SHIELDS TO THE SO-CALLED "GROUND" PIN ON THE DB CONNECTOR -- IT USUALLY
GOES TO THE CIRCUIT BOARD, NOT THE CHASSIS. CONNECT SHIELDS TO THE
CONNECTOR SHELL!
I also recommend use of a good twisted pair, like CAT5, for serial
connections. See the chapter in
http://audiosystemsgroup.com/RFI-Ham.pdf about Solving Problems in the
Shack, also shown in the Power Point
http://audiosystemsgroup.com/HamInterfacing.pdf
73, Jim Brown K9YC
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