[K3] ALC In DATA A

[Joel Black-2]

I will try to do this as concisely as possible so no rabbit trails are run… I’ll try by stating below are the conditions in question. Despite what you may *think*, there is no reason to talk about anything other than this in this thread.

I have owned my K3 for several years. In that time, when using data modes in DATA A, I have been told consistently to set ALC so that the fifth bar just flickers. In the past, when I have turned ALC all the way down, I have gotten no output power. This has bitten me more than once.

I have read other groups / boards where folks are adamant about setting *every* radio so that ALC is zero. My response is to state that the K3 (and KX3) require four bars of ALC with the fifth bar just flickering. I also know there are other radios out there (Icom comes to mind, but I’m not sure) on which you cannot turn ALC to zero. ALC bottoms out and it still shows ALC.

Last night, such a discussion occurred on another group. I once again stated the K3 ALC settings. Now I’ve had to go back and rescind my comments.

I just tested and I can turn ALC down so that no ALC shows and I still transmit according to the K3’s RF wattmeter.

My question is has something changed in the K3’s ALC circuit? If not, have I misunderstood what was said about setting the ALC when using DATA A?

I use LINE IN / LINE OUT when using DATA A. I always watch the ALC meter and make sure that I have four bars with the fifth bar flickering. In the past, if I set it for lower than that, I wouldn’t get any output. Now (this morning), If I set for *minimum* ALC (no bars, but not zero), I still get output. I do not remember this being the case but I could be wrong.

Current firmware in the K3 is 5.35.

Thank you.

73,
Joel - W4JBB
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[Lyle Johnson]

Hello Joel!

In the K3, the first 5 bars of the "ALC" bargraph indicator are just
audio level.  Traditional ALC - reducing drive to to transmit strip to
control power level - does not occur until somewhere between the 5th and
6th bar.  So the directions to have 4-5 bars of ALC just means that the
audio drive level to the DSP is at the correct level for the transmit
power control loop to work properly without introducing distortion from
the audio leveling control logic.

Underdrive it and you'll likely get creeping power levels as the MCU in
the K3 attempts to control peak power by adjusting the RF drive level in
the transmit path.  Overdrive it and you may get some amount of
distortion from the transmit audio gain control loop within the DSP code.

The DSP code in the K3 that monitors, limits and reports audio drive
levels has not changed in years.

On 10/16/15 4:18 AM, Joel Black wrote:
> ...I have owned my K3 for several years. In that time, when using data modes in DATA A, I have been told consistently to set ALC so that the fifth bar just flickers...
>
> I have read other groups / boards where folks are adamant about setting *every* radio so that ALC is zero.

With the 5th bar flickering the "ALC" in the K3 *IS* zero in the sense
they are being so insistent about.  ALC in the traditional sense does
not being until the 6th bar comes on.


73,

Lyle KK7P
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[Don Wilhelm-4]

Joel,

The 4 bars solid with the 5th flickering still is the proper way to set
the audio drive to the K3.
Actually that is the "no ALC" point for the K3.  The 1st 4 bars of the
ALC meter are similar to a "VU meter" to allow you to properly adjust
the audio drive.  Failure to provide sufficient audio drive will cause
the K3 to "power hunt" and the power output will not be stable.
Set the audio correctly and control the power with the power knob.
The onset of ALC is indicated by the 5th bar on the meter, so 4 bars is
still "zero ALC".

Yes, that is different than most other transceivers and the internet
'wisdom' which typically says to set the power to maximum and control
the actual power output by adjusting the audio level.
The K3 controls power differently than most other transceivers.  It will
attempt to increase the RF drive to try to develop the power requested
by the power knob.  If there is not sufficient audio, that cannot be
obtained and the power will not be steady.

So there was no need to rescind your statement - the proper statement is
that the K3 is different than most others.

73,
Don W3FPR

On 10/16/2015 7:18 AM, Joel Black wrote:
> I will try to do this as concisely as possible so no rabbit trails are run… I’ll try by stating below are the conditions in question. Despite what you may *think*, there is no reason to talk about anything other than this in this thread.
>
> I have owned my K3 for several years. In that time, when using data modes in DATA A, I have been told consistently to set ALC so that the fifth bar just flickers. In the past, when I have turned ALC all the way down, I have gotten no output power. This has bitten me more than once.
>
> I have read other groups / boards where folks are adamant about setting *every* radio so that ALC is zero. My response is to state that the K3 (and KX3) require four bars of ALC with the fifth bar just flickering. I also know there are other radios out there (Icom comes to mind, but I’m not sure) on which you cannot turn ALC to zero. ALC bottoms out and it still shows ALC.
>
> Last night, such a discussion occurred on another group. I once again stated the K3 ALC settings. Now I’ve had to go back and rescind my comments.
>
>

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[Joel Black-2]

Thanks to all who responded. It sure cleared it up for me. It was explained very well.

73,
Joel - W4JBB

> On Oct 16, 2015, at 6:18 AM, Joel Black <[hidden email]> wrote:
>
> I will try to do this as concisely as possible so no rabbit trails are run… I’ll try by stating below are the conditions in question. Despite what you may *think*, there is no reason to talk about anything other than this in this thread.
>
> I have owned my K3 for several years. In that time, when using data modes in DATA A, I have been told consistently to set ALC so that the fifth bar just flickers. In the past, when I have turned ALC all the way down, I have gotten no output power. This has bitten me more than once.
>
> I have read other groups / boards where folks are adamant about setting *every* radio so that ALC is zero. My response is to state that the K3 (and KX3) require four bars of ALC with the fifth bar just flickering. I also know there are other radios out there (Icom comes to mind, but I’m not sure) on which you cannot turn ALC to zero. ALC bottoms out and it still shows ALC.
>
> Last night, such a discussion occurred on another group. I once again stated the K3 ALC settings. Now I’ve had to go back and rescind my comments.
>
> I just tested and I can turn ALC down so that no ALC shows and I still transmit according to the K3’s RF wattmeter.
>
> My question is has something changed in the K3’s ALC circuit? If not, have I misunderstood what was said about setting the ALC when using DATA A?
>
> I use LINE IN / LINE OUT when using DATA A. I always watch the ALC meter and make sure that I have four bars with the fifth bar flickering. In the past, if I set it for lower than that, I wouldn’t get any output. Now (this morning), If I set for *minimum* ALC (no bars, but not zero), I still get output. I do not remember this being the case but I could be wrong.
>
> Current firmware in the K3 is 5.35.
>
> Thank you.
>
> 73,
> Joel - W4JBB

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