KX3 SSB ALC Mic Gain - a new problem

[VK7JB]

Hi All,

 

Apologies if this question posts twice - my attempt yesterday was
unsuccessful, so here goes again.

 

I've been running KX3 #2511 for several years on SSB with the MH3 mic and
with settings:  Mic gain 35 and compression 12.  It's worked flawlessly and
that combination of settings has

given me an ALC indication of 5 bars while speaking normally.  I'm running
the latest firmware.

 

Yesterday, I noted that I had no RF output on SSB and find that now I get no
ALC indication until the Mic gain is advanced to the maximum setting of 80.
Nothing else has changed in my

setup.  I've checked that MIC Bias is set to ON and the TX EQ settings have
not changed.  I've also checked and there is indeed a bias voltage on the
Mic socket.

 

I can still run digital modes in DATA mode A,  using an external soundcard
connected to the KX3 mic socket via an adapter cable and I easily get 4 bars
of ALC with the 5th flickering with a Mic gain of 35.  That hasn't changed.

 

I don't have another MH3 mic to check whether it's the microphone that's at
fault here, but that's my suspicion.

 

Any ideas where to look next?

 

Many thanks,

 

John

VK7JB

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[Don Wilhelm]

John,

Try backing down the MIC Gain setting to something low or mid-range.
If you get the mic voltage too high, the mic amplifier detects that and
inserts attenuation that will shut the audio from the mic down.

So bottom line, start with a low MIC Gain setting and increase it until
you see 5 to 7 bars on the ALC meter.

73,
Don W3FPR

On 10/7/2017 7:53 PM, Dr John H Farmer wrote:

> Yesterday, I noted that I had no RF output on SSB and find that now I get no
> ALC indication until the Mic gain is advanced to the maximum setting of 80.
> Nothing else has changed in my
>
> setup.  I've checked that MIC Bias is set to ON and the TX EQ settings have
> not changed.  I've also checked and there is indeed a bias voltage on the
> Mic socket.
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