[TenTec] Orion Mic Woes - Sounds like RFI but Wasn't

[Jim Brown]

On Sat, 18 Dec 2004 11:30:12 -0500, Tom Wagner wrote:

>The
>Orion really, really does not like pin 2 to
>be grounded. (In the Heil setup, pin 1 is the
>mic lead center conductor and pin 2 is 
>the shield.) This was the cause of the 
>oscillation/instability. 

Apparently Heil has never heard of the IEC and AES standards for wiring of XL 
connectors used for audio. These are international standards. The lowest numbered 
pin is ALWAYS the shield. Next one or two contacts are audio.  These are not new 
standards -- they have been in existence for more than 50 years.  There were two 
different standards for whether pin 2 or pin 3 was positive polarity with respect to 
the other. That difference was resolved about 10 years ago. But pin 1 has ALWAYS 
been the shield contact, and 2 and/or 3 have always carried audio.  When there are 
control circuits, those circuits should be on the higher number contacts. 

BTW -- I'm a member of the AES Standards Committee Working Group that 
maintains these standards.