6400 Balanced mic input?

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  • Updated 2 years ago
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  • (Edited)
In testing the mic input, on the 6400 it was discovered that the ring connection was connected to case ground as well as the sleeve.

That being said, how can you call the input Pseudo-balanced?
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Bill -VA3WTB

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Posted 2 years ago

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Tim - W4TME, Customer Experience Manager

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Official Response
Technically pseudo-balanced input it is an unbalanced input into the codec, but it is wired as a balanced input from the connector to the input of the codec where it is converted to an unbalanced input (mic- and ground are bonded together).  This prevents multiple ground points in the input circuit when the transducer input (mic) is wired for a balanced input.  The advantage is that it makes the unbalanced input into the codec less susceptible to RFI.
(Edited)
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Bill -VA3WTB

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Tim can you help answer this...

One last question for Tim ...”looking at the 1/8 inch mic jack on the rear of the 6400...if metered with a DVM in resistance mode, should both the TIP and Ring be well above ground potential with nothing external connected to the jack?” 
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Tim - W4TME, Customer Experience Manager

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Ring will be at ground as the MIC- is grounded at the codec input.
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Terry AB2UE

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What i would like to know since the mic[-] is grounded, would a 13.8vdc power supply that has a grounded DC[-] output[my Astron does] cause a problem ?  
Do the Flex Radio service technicians use 'floating or grounded' DC[-] output power supplies ?