K3S Data Mode Question

[Tom Richardson]

I bought a new K3S two weeks ago, and I am trying to learn how to use
it. I apologize if the answer to this issue is obvious, but it isn't
obvious to me.

I am trying to use the K3S in data mode (JT65 or AFSK). I have the
DATA MD set to DATA A, MIC SEL to LInE In, MODE to DATA, and LINE
input gain to 10. Everything seems to work until I try to increase the
power output beyond 12 watts. At 13 watts and beyond, the power
abruptly drops down to one or two watts.

I can see the signal in my P3, as well as hear it in the K3S monitor.

I am using either WSJT-X, DM780 or fldigi software with identical results.

The K3S seems to work fine in CW and SSB modes.

I would appreciate any insights that might help me understand what is happening.

73,

Tom
N4WE
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[Don Wilhelm]

Tom,

Are you driving your audio level correctly.
With the K3S (or K3 or KX3 or KX2) you need to set the soundcard level
and the line in level so you have 4 bars solid on the ALC meter with
possibly the 5th bar flickering.

Then adjust the power output to the desired level with the power knob.

This is essential for the K3S to maintain good power control. Power
control will be erratic if you do otherwise.

Ignore the common internet advice to set the power to maximum and use
the audio level to control the power - that just does not work with the
K3S because its power control mechanism is different than other
transceivers.

As far as the "No ALC" internet advice goes, for the K3S, the onset of
ALC is at the 5th bar, so 4 bars is actually the No ALC point.  The 1st
4 bars are there to help you adjust the audio level - sort of like a VU
Meter.

73,
Don W3FPR

On 9/12/2016 8:41 PM, Tom Richardson wrote:

> I bought a new K3S two weeks ago, and I am trying to learn how to use
> it. I apologize if the answer to this issue is obvious, but it isn't
> obvious to me.
>
> I am trying to use the K3S in data mode (JT65 or AFSK). I have the
> DATA MD set to DATA A, MIC SEL to LInE In, MODE to DATA, and LINE
> input gain to 10. Everything seems to work until I try to increase the
> power output beyond 12 watts. At 13 watts and beyond, the power
> abruptly drops down to one or two watts.
>
>

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[Don Wilhelm]

Tom,

Another thought - take a look at the DC voltage in the VFO B alternate
display.
If your voltage is dropping much below 12.5 volts, that might be the
problem.

Should that be the problem, check your power supply output, it should be
13.8 volts or higher - preferably 14.3 volts or more.
All power supply connections should be tight to reduce voltage drop.
Run the power cable directly from the power supply to the K3.  If you
use a "Rigrunner" or similar DC distribution device, use it for powering
accessories and not the K3.  A fused Rigrunner introduces at least 4
points of contacts, each of which can contribute to voltage drops.

Is this a K3S/100 or a K3S/10?  If it is a K3S/100 then the switchover
from low power to the KPA3 occurs above 12 watts. Check that the circuit
breaker on the back of the KPA3 is not in a tripped condition.

If all checks out OK and you still have problems, contact
[hidden email] for some additional ideas.

73,
Don W3FPR

On 9/12/2016 8:41 PM, Tom Richardson wrote:

> I bought a new K3S two weeks ago, and I am trying to learn how to use
> it. I apologize if the answer to this issue is obvious, but it isn't
> obvious to me.
>
> I am trying to use the K3S in data mode (JT65 or AFSK). I have the
> DATA MD set to DATA A, MIC SEL to LInE In, MODE to DATA, and LINE
> input gain to 10. Everything seems to work until I try to increase the
> power output beyond 12 watts. At 13 watts and beyond, the power
> abruptly drops down to one or two watts.
>
>

______________________________________________________________
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