Microphone Resistor

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Microphone Resistor

Jeff Burns-3
My new MD2 microphone should arrive tomorrow, and I am trying to decide what
to do about the resistor between pin 6 and pin 1. I have a hand microphone
with a Heil HC-4 and a N0MF pre-amp in it that I want to continue to use. It
has a 1k resistor between pin 1 and pin 6 in per the instructions for the
pre-amp.

 

It seams I have three options.

 

1. Remove the 1k resistor from the hand microphone, and install the 5.6k
resistor in the K2. Will this provide enough current to run the pre-amp in
the hand microphone?

 

2. Add the 5.6k resistor to the K2 and leave the resistor in the hand
microphone. Will the hand microphone then draw too much current?

 

3. Put the 5.6k resistor in the MD2. I know this will work, but requires
fitting the resistor into the connector.

 

What is the best option?

 

Jeff Burns

AD9T

 

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Re: Microphone Resistor

Don Wilhelm-3
Jeff,

Let me offer one more option.

Put a 1.2k resistor in parallel with the 5.6k when (and only when) the mic
containing the preamp and HC5 is plugged in.

Here is how to do that easily:  Solder the 5.6k resistor on the mic jack
between pins 1 and 6 as instructed for the MD2,  then solder a 1.2k resistor
on the mic jack between pins 1 and 5.  IMPORTANT - remove any connection at
the mic header on pin 5 (FUNC is not used).  Now, inside your mic plug for
the HC5/preamp mic, place a jumper between pins 5 and 6.

When you plug in the Elecraft mic (any stock Elecraft mic), you have the
proper 5.6k resistor in the 5 volt line.  When you plug in the mic having
the jumper installed, the 1.2k resistor is placed in parallel (through the
jumper) with the 5.6k resulting in a resistance of 988 ohms which is likely
close enough to 1k (use 1.3k instead of the 1.2k and the result will be 1055
ohms if you prefer that value).

73,
Don W3FPR

----- Original Message -----

> My new MD2 microphone should arrive tomorrow, and I am trying to decide
> what
> to do about the resistor between pin 6 and pin 1. I have a hand microphone
> with a Heil HC-4 and a N0MF pre-amp in it that I want to continue to use.
> It
> has a 1k resistor between pin 1 and pin 6 in per the instructions for the
> pre-amp.
>
>
>
> It seams I have three options. ...


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