MD2 Heil Desk Microphone for the K2

[Roger Marrotte]

I just received the MD2 microphone and the PL2T Pro-Line microphone boom I
ordered a few days ago.  REALLY REALLY nice looking! And at about half
price, what a deal.  I have it set up.  I had to install 8 jumper blocks
onto the microphone header and a 5.6K resistor across pins 1-6 on the rear
of the 8 pin mike connector (supplied with the mike).  My problem/question
is this.  I had been using a regular Heil mike that had low gain for the K2
and a few years ago I read somewhere about changing a resistor to increase
the gain.  The change helped.  I don't know which resistor it was! I'm not
even sure which board it was on.  I think a 10K resistor was involved
somehow.  Does anyone know which resistor it might have been and do I have
to change it back to it's original value to have the new MD2 mike work
optimally?

Roger, W1EM


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[Brian Mury-3]

On Mon, 2004-22-11 at 17:01 -0500, Roger Marrotte wrote:
> is this.  I had been using a regular Heil mike that had low gain for
> the K2 and a few years ago I read somewhere about changing a resistor
> to increase the gain.  The change helped.  I don't know which resistor
> it was! I'm not even sure which board it was on.  I think a 10K
> resistor was involved somehow.

That would be R14 on the bottom of the SSB board. Original value is 1K.

> Does anyone know which resistor it might have been and do I have
> to change it back to it's original value to have the new MD2 mike work
> optimally

I'm not sure, but I would change it back.

--
73, Brian
VE7NGR

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[Ron D'Eau Claire-2]

It probably doesn't matter with the new mic, Roger, but if you want to put
the K2 back the way it was, the resistor in question is R14 on the SSB
board. The original value was 1k and it was common to replace it with a 5.6
k resistor to increase the audio level.

Depending upon how long ago you made the change, you might check another
resistor too on the SSB board: R2. The first iteration of this "mod"
recommended swapping R2, which should be 5.2k, with R14, originally 1k.

Reducing R2 from 5.2k to 1.0k also increased the gain, but it was noted that
it was then possible to over-drive Balanced Modulator U5, creating unwanted
distortion.

So if you did the mod a long time ago, it's possible you swapped resistors.
Check R2 and make sure it's 5.2k

Ron AC7AC


-----Original Message-----
I just received the MD2 microphone and the PL2T Pro-Line microphone boom I
ordered a few days ago.  REALLY REALLY nice looking! And at about half
price, what a deal.  I have it set up.  I had to install 8 jumper blocks
onto the microphone header and a 5.6K resistor across pins 1-6 on the rear
of the 8 pin mike connector (supplied with the mike).  My problem/question
is this.  I had been using a regular Heil mike that had low gain for the K2
and a few years ago I read somewhere about changing a resistor to increase
the gain.  The change helped.  I don't know which resistor it was! I'm not
even sure which board it was on.  I think a 10K resistor was involved
somehow.  Does anyone know which resistor it might have been and do I have
to change it back to it's original value to have the new MD2 mike work
optimally?

Roger, W1EM



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[Roger Marrotte]

Thanks Ron,

I changed R14 on the ssb board from 10K back to a 1K resistor.  I don't know
why I used a 10K resistor.  R2 was the original.  All seems fine.  This is a
real nice looking mike and the swing arm mike boom is really well made. It's
sturdy, smooth and quiet.  I'll get on the air (SSB) with a friend tomorrow
night and try to get a signal report with the new mike.  I've really become
a cw nut lately, trying to get 100 countries on 30m.  The K2 with the DSP
board really works like a champ on that 30m noise.  I have a Kenwood TS-2000
and it works like you know what compared to the K2.

73, Roger, W1EM
----------------------


It probably doesn't matter with the new mic, Roger, but if you want to put
the K2 back the way it was, the resistor in question is R14 on the SSB
board. The original value was 1k and it was common to replace it with a 5.6
k resistor to increase the audio level.

Depending upon how long ago you made the change, you might check another
resistor too on the SSB board: R2. The first iteration of this "mod"
recommended swapping R2, which should be 5.2k, with R14, originally 1k.

Reducing R2 from 5.2k to 1.0k also increased the gain, but it was noted that
it was then possible to over-drive Balanced Modulator U5, creating unwanted
distortion.

So if you did the mod a long time ago, it's possible you swapped resistors.
Check R2 and make sure it's 5.2k

Ron AC7AC

-----Original Message-----
I just received the MD2 microphone and the PL2T Pro-Line microphone boom I
ordered a few days ago.  REALLY REALLY nice looking! And at about half
price, what a deal.  I have it set up.  I had to install 8 jumper blocks
onto the microphone header and a 5.6K resistor across pins 1-6 on the rear
of the 8 pin mike connector (supplied with the mike).  My problem/question
is this.  I had been using a regular Heil mike that had low gain for the K2
and a few years ago I read somewhere about changing a resistor to increase
the gain.  The change helped.  I don't know which resistor it was! I'm not
even sure which board it was on.  I think a 10K resistor was involved
somehow.  Does anyone know which resistor it might have been and do I have
to change it back to it's original value to have the new MD2 mike work
optimally?

Roger, W1EM


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