fixed audio output on mic socket

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fixed audio output on mic socket

Vk2NU
Hi All,

I'm just playing about with my K2 and have performed the mod to get a fixed
audio out on pin 8 on the mic socket as per LA3ZA's instructions, using a
10k resistor between R3 and the mic socket.

This works fine, but the audio out isn't quite enough to drive my PC
soundcard to the level I would like. I have a small board here (as per Don's
W3FPR design) for the small audio amp, but would prefer if possible to get
the audio out of the mic socket without having to install this board.

My question is.....would I be-able to get more audio out of pin 8 if I
change the value of the 10k resistor in LA3ZA's mod ??

Cheers All

David, VK2NU


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RE: fixed audio output on mic socket

Don Wilhelm-3
David,

I would say the answer is 'maybe'.  And the reason for the uncertainly is
that it depends on what you are driving.    The impedance of whatever you
connect to the far end of the resistor will determine how much current wil
be drawn and the voltage developed across it.

You can install the fixed audio board between the front panel and control
board if you lay the resistor and capacitors down flat on the board.  The
fixed audio board will provide up to about 3 volts to the soundcard, and
that is much more than enough to overdrive it.

73,
Don W3FPR

> -----Original Message-----
>
> I'm just playing about with my K2 and have performed the mod to
> get a fixed
> audio out on pin 8 on the mic socket as per LA3ZA's instructions, using a
> 10k resistor between R3 and the mic socket.
>
> This works fine, but the audio out isn't quite enough to drive my PC
> soundcard to the level I would like. I have a small board here
> (as per Don's
> W3FPR design) for the small audio amp, but would prefer if possible to get
> the audio out of the mic socket without having to install this board.
>
> My question is.....would I be-able to get more audio out of pin 8 if I
> change the value of the 10k resistor in LA3ZA's mod ??
>
> Cheers All
>
> David, VK2NU
>
>
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RE: fixed audio output on mic socket

Sverre Holm-2
In reply to this post by Vk2NU
>
> My question is.....would I be-able to get more audio out of
> pin 8 if I change the value of the 10k resistor in LA3ZA's mod ??
>

As W3FPR said, maybe, but in any case not by very much, and probably not by
enough to really make a difference.

You could fit the audio amplifier board on the outside of the rig and bring
out 5 or 8 Volts through the mic connector if you don't want to use an
external power supply.


73

Sverre
LA3ZA
http://www.qslnet.de/la3za/
 

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