[Elecraft] MH2 Mic and MKII interface

[Joe Subich, W4TV]

Kenwood mic does not use bias (it is dynamic).  Elecraft requires
bias.  Measure between pins 1 and 7 to confirm bias (2.2 to 3.3V -
industry standard for AV mics).

Also check to make sure the microphone is wired correctly - mic
ground must be on pin 7, PTT ground must be on pin 8.  If the two
are reversed the mic will not receive bias.  Elecraft connects
both 7 and 8 to the same ground but the mic and PTT grounds are
different in microKEYER/microKEYER II (and most other manufacturers).

73,

    ... Joe, W4TV


On 2/24/2013 1:05 AM, Ricardo PY2PT wrote:
> Dear Joe,
>
> I've tried both jumpers position and nothing!!!
> With my kenwood hand mic everything is ok. But with the MH-2 mic (even changing the jumper position) nothing!!
>
> Best Regards
> Em 23/02/2013, às 23:31, Joe Subich, W4TV escreveu:
>
>>
>> The MH2 is an electret mic wired with a Foster plug having Elecraft's
>> Kenwood compatible pin assignments.  The microHAM DB37-EL-K3R and
>> DB37-EL-K23 cable sets are configured for the Electaft/Kenwood standard
>> and the supplied Foster to RJ-45 adapter cable allows connecting the
>> MH2 to the rear panel MIC jack (RJ45).
>>
>> Since the MH-2 is an electret mic and requires bias voltage on pin 1,
>> it is necessary to install the "electret" jumper for the RJ-45 jack
>> located just in front of the three trimmers in the center of the MK II
>> circuit board as shown in step 5 of "Preparing microKEYER II for Use" -
>> page 8 of the microKEYER II User Manual.
>>
>> 73,
>>
>>    ... Joe Subich, W4TV
>>        microHAM America, LLC.
>>        http://www.microHAM-USA.com
>>        http://groups.yahoo.com/group/microHAM
>>
>>
>> On 2/23/2013 7:25 PM, Ricardo PY2PT wrote:
>>> Dear guys,
>>>
>>>
>>> Please, any friend use the hand mic (MH-2) with a MicrokeyerII interface?
>>>
>>>
>>> Best Regards
>>>
>>>
>>>
>>> Ric
>>> PY2PT
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>