[Elecraft] Balanced Mic to Unbalanced Connection Follow Up Question

[Joe Subich, W4TV]

 > A capacitor in series with one side of the balanced line.

First, a dynamic mic element as is found in the PR-781 is neither
balanced nor unbalanced.  That is determined by the external
connections (the input circuit to which the mic element is
connected).  I know of no current amateur transceiver that has a
truly *balanced* microphone input.  However, professional and
semiprofessional audio mixers (as well as "effects processors",
microphone equalizers and mic preamps) often have balanced
microphone inputs.

Second, a capacitor is not needed with the Elecraft K3/K3S - one
simply needs to *TURN OFF BIAS* (MENU:MIC SEL and tap #2).

The capacitor is only required for "Brand I" radios in which one
can not turn off the bias.

73,

    ... Joe, W4TV


On 2020-06-10 10:05 AM, Gil Drynan wrote:
> 
> The PR-781 does not like the DC bias supplies from many newer ham radios.
> A capacitor in series with one side of the balanced line. Heil offers a
> specialized cable for three pin XLR mike to the mike jack on front of
> different brands of transceivers. Contains the capacitor as required.
> Works for me.
> 
> Gil  W7GIL
> 
> 
> 
> 
>> All:
>>
>> I have a follow-up question regarding balanced mics and unbalanced
>> connections. I'm about to connect a balanced dynamic microphone (Heil
>> PR-781) to the rear mic input on my K3S which has a 1/8" unbalanced mono
>> connection.
>>
>> One recommendation was to connect XLR pin #2 mic (+) to the tip of the
>> 1/8" jack and pin #3 mic (-) to the sleeve. In this case, pin #1 or
>> ground is left floating with no connection. A 1/8" mono jack was
>> recommended for this setup.
>>
>> The other recommendation was to connect pin #2 to the tip and pin #1 and
>> #3 to the sleeve of the 1/8" jack. It was also suggested that I can use
>> either a 1/8" mono or a stereo TRS jack in both cases.
>>
>> So which is correct?
>>
>> Tony -K2MO
>>