[Elecraft] [K3] Mic Experimentation with Kenwood MC-60

[Joe Subich, W4TV]

 > You do need to speak close to the mic when transmitting, it is
 > designed for that kind of use.

All of the Kenwood dynamic mics (desk or hand) have similar sensitivity
based on the specifications ... between -69 and -71 dB at 500 - 600 
Ohms.  That indicates they are designed for "close talking" - the
hand mics (MC-42S, MC-43S) specify their sensitivity at 2 cm from the
mic.

Since audio is a square law phenomena, the microphone will be 6 dB
less sensitive with each doubling of the distance so working 16"
away from a "desk mic" will result in more than 20 dB less output
than holding it 1" from the mouth.  Note: the preamp in the MC-60A
has a gain of 12 dB (Preamp in = Preamp out).

73,

    ... Joe, W4TV


On 3/6/2011 2:19 AM, George A. Thornton wrote:
> I have a Kenwood MC-60, I bought it new about a year ago for use with an
> older Kenwood 930s.  It has been used lightly and is in good condition.
>
> I just tried it on my K3, it works fine for me with the mic preamp off
> and the K3 set for FP L.
>
> I am driving it with mic gain set at about 23, compression high 20's.
> Audio sounds fine when I test transmit and use the monitor feature to
> hear myself.
>
> During transmit, I am getting strong power out.
>
> This mic has not been modified and the pinouts are as delivered from the
> factory.
>
> There is an on-off button on the mic, leave that off.  There seems to be
> no difference whether setting the mic for 50 or 500 ohms.
>
> You do need to speak close to the mic when transmitting, it is designed
> for that kind of use.
>
> Maybe there is something wrong with the mic you are using.
>
>
>
>
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Phil Hystad
> Sent: Saturday, March 05, 2011 8:02 PM
> To: Elecraft Reflector
> Subject: [Elecraft] [K3] Mic Experimentation with Kenwood MC-60
>
> So, I asked a question late last night but no responses.  So, either no
> one cares or maybe I got lost in the noise.  But, that is OK -- I will
> try again.
>
> I am confused and mystified by a mic that I borrowed from a friend to
> try out with the K3.  It is a Kenwood MC-60 and I think it is fairly new
> and I only have a day or two to play with this so I want to make use of
> that time.
>
> I am discovering that I don't understand all there is about microphones
> and the K3.  For example, when you use the MENU to set the Mic to
> something like FP.L or FP.H, what is the true meaning of the L and H.  I
> know that the document says Low gain and High gain but how am I to
> interpret this.  Does H mean that the mic has high gain or does it mean
> that it needs high gain.
>
> This MC-60 mic has a preamplifier on it and when this amp is off, I have
> trouble getting the ALC meter to measure anything.  I do the test of
> speaking normally into the mic but with the mic gain set to 60 I have to
> either shout or speak VERY CLOSELY to the mic to make the ALC meter move
> at all.  This does not seem right.  I get the same behavior whether the
> mic setting is FP.L or FP.H.  By the way, Bias is set off as I believe
> it should be with a dynamic mic.
>
> Now, I have done some tests on-air with a few friends and they say my
> audio sounds OK.  Right now, I have the compression either zero or very
> low and I am forgetting which audio report I got with which setting.
> But, the compression setting didn't seem to make a whole lot of
> difference.
>
> Also, another question --- this mic has a preamp and I am wondering if
> there is wisdom in using the preamp versus the mic gain set to a high
> value on the K3.
>
> And, lastly -- I checked the history of some discussion on Kenwood mics
> and the K3 and I see there is some discussion about the pin wiring of
> whether pin 5 is used or pin 6 for something or other.  I was under the
> impression that the K3 was using the Kenwood mic wiring so what is this
> question on pin 5 versus pin 6?
>
> Yes, when it comes to microphones I do not know very much.  I am about
> 90 percent CW so I obviously do not care about audio too much but I do
> want things to sound OK without over driving the K3.
>
> 73, phil, K7PEH
>
>
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