Elecraft

[KPA500] K3S/KPA500/KAT500 - Adjusting TX Power

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Bob McGraw - K4TAX

Re: Adjusting Audio Level for Digital Modes

As an operational note for WSJT-X. Version 1.8.0 -rc2

To adjust the audio level via the software slider marked *Pwr* on the
right, I find it more precise to place the cursor just above or just
below the slider bar, depending which way you wish the audio level to
go, and click the left mouse button one time. This will move the slider
to the next step. I find this to be easier than placing the cursor on
the slider and trying to move it up or down.

Also you will find on the WSJT-X Audio tab via the F2 menu, there are
two boxes, if checked the software will remember the settings for each
band for both /TRANSMIT /audio level and /TUNE/ audio level functions.
You must set your Windows SPEAKER level to the same value each time for
this to be effective.   I use 25% {or -21 dB} in my configuration.   The
WSJT-X *Pwr *slider operates about mid scale for correct level to the
K3S.   Due to differences in computers, sound cards and etc. you will
need to experiment a bit in order to get the exact numbers nailed down
as required by your station. Do anticipate that Windows _will change_
the SPEAKER value if and when you run other applications requiring the
sound card function.

If you are not getting good decodes, I suggest you check the Recording
Devices level. Right click the Speaker ICON and select Recording
Devices. Specifically the USB CODEC Properties and Levels to see that
the level control is about 50% to 55% {-1 dB to + 1 dB}. Via the
CONFIG menu I did adjust the K3S Line Out from the default value of "nor
010" to a value of "nor 005". This will reduce the likely hood of sound
card overdrive or saturation of the transformers in the K3S.

73
Bob, K4TAX

On 9/8/2017 5:36 PM, MaverickNH wrote:

> At present, I have my PC's USB Audio Codec Playback Level set at 35%, and am
> adjusting ALC with the MIC knob. With the WSTJ-X Tune ON, I'm slowly
> increasing MIC until the 3rd bar shows. Further increase jumps directly to
> the 5th bar, with no 4th bar appearing or flashing 5th bar.
> I could swear I used to be able to get that flickering 5th bar. Must be I
> have something else set incorrectly?
>
> But either way, I must have nudged the MIC button as now things seem OK. Any
> way to lock that? As such, when pressing the K3S TUNE button ON, the POWER
> knob on the K3S adjusts power smoothly up on the K3S (as seen on the P3TXMON
> and K3S display) with KPA500 off. With KPA500 ON, increasing K3S power knob
> increases KPA500 display power, with the P3TXMON going up too.
>
> I'll have to add "check ALC/MIC setting to my WSJT-X Cheat Sheet. Thanks for
> the help guys.
>
> BRET/N4SRN
>
>
>
> --
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Mike Harris-9

Re: Adjusting Audio Level for Digital Modes

How about using the mouse scroll wheel, it adjusts the power in 0.1dB
steps. At least it does on my Win7 box.

The waterfall sliders also respond to the scroll wheel.

Regards,

Mike VP8NO

On 08/09/2017 21:52, Bob McGraw K4TAX wrote:
> As an operational note for WSJT-X. Version 1.8.0 -rc2
>
> To adjust the audio level via the software slider marked *Pwr* on the
> right, I find it more precise to place the cursor just above or just
> below the slider bar, depending which way you wish the audio level to
> go, and click the left mouse button one time. This will move the slider
> to the next step. I find this to be easier than placing the cursor on
> the slider and trying to move it up or down.
How about using the mouse scroll
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Wes Stewart-2

Re: Adjusting Audio Level for Digital Modes

In reply to this post by Don Wilhelm

My testing with WSJT-X (FT8) "tune" for an audio tone, says that any ALC
indication at all, no matter where it is, gives exactly the same RF output.
That said, _and this may only apply to my situation, _the signal is cleaner with
only three bars lit. I'm seeing 52 Hz spurs at -50 dBc for anything above
three. This is with a K3 operating at 5W into a dummy load.

Maybe someone else with a spectrum analyzer can take a look at this.

Wes N7WS

On 9/8/2017 3:59 PM, Don Wilhelm wrote:

> Bret,
>
> You likely have the LINE IN level in the K3/K3S set to either the high or low
> end of the range. Set it first for midrange (about 30), and then set the
> soundcard "speaker" output slider for about 50%, and set the WSJT-X slider
> also to about 50%. Then see what the ALC meter reads during a transmit.
> You should be able to do that in TX TEST mode, or working into a dummy load so
> there is no need to put those "testing" signals on the air.
>
> With the K3 LINE IN set to midrange, adjust the computer sliders so you get
> close to the 4 bars with 5th bar flashing. Then fine tune that with the K3
> LINE IN to get to the right level.
>
> If you cannot obtain the 5th bar flashing, settle for 4 bars solid with the
> 5th bar not illuminated at all.
>
> Don W3FPR

MaverickNH

Re: Adjusting Audio Level for Digital Modes

In reply to this post by Don Wilhelm

That seemed to do the trick Don. Edging the WSJT-X Power Slider down to
mid-scale and K3S MIC LINE IN to ~30 gave me the wiggle room to get the 5th
bar flashing. In fact, flashing just a bit was less effective than flashing
a lot, but still short of solid 5th bar ON. But I guess the 5th bar flash
density is a matter of the interactive balance of the other settings. But
now the K3S Power Knob give relatively smooth and linear power change with
rotation. Thanks!

Bret/N4SRN

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Don Wilhelm

Re: Adjusting Audio Level for Digital Modes

Thanks Bret, glad you found success.
This note is information to all who are using any soundcard digital modes.

This is a situation of having too many controls that do the same thing
(adjust the audio level). There are 2 in the computer - soundcard
"speaker" level and the WSJT-X "power level".
In the K3/K3S, there is the LINE IN gain.

None of those controls should be set to either the extreme low range or
high range. When adjusting, start with all at midrange values.

Setting the soundcard level (Speaker or WSJT-X POWER slider) to a high
value can create soundcard distortion.
When the K3 LINE IN gain is at either at the high or low ends of the
range, each increment of change will result in a large difference (dBs
are logarithmic), so strive for a midrange setting of LINE IN (mic gain).

73,
Don W3FPR

On 9/9/2017 6:43 PM, MaverickNH wrote:

> That seemed to do the trick Don. Edging the WSJT-X Power Slider down to
> mid-scale and K3S MIC LINE IN to ~30 gave me the wiggle room to get the 5th
> bar flashing. In fact, flashing just a bit was less effective than flashing
> a lot, but still short of solid 5th bar ON. But I guess the 5th bar flash
> density is a matter of the interactive balance of the other settings. But
> now the K3S Power Knob give relatively smooth and linear power change with
> rotation. Thanks!
>
> Bret/N4SRN
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> ______________________________________________________________
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kstover

Re: [KPA500] K3S/KPA500/KAT500 - Adjusting TX Power

In reply to this post by Wes Stewart-2

The difference is Data A mode.
In Data A mode ALC action doesn't start until the fifth bar is lit AFAIK
it's been that way from the beginning.

With Elecraft rigs you don't control power out by adjusting audio level.
Adjust your sound card line out to 50%, or less, adjust your software to
50% or less, adjust the K3(S) line-in. Fine tune the line-in level to 4
bars steady and the 5th barely flickering. Once set don't fiddle with
it. Adjust power out with ye olde power knob.

If the manual says 5-7 bars for digital modes it needs fixing.
Data A, AFSK, SSB (upper or lower running a digital mode)should all have
zero ALC action. Been that way since PSK31 was new. On an Elecraft rig
that means 4 with 5 flickering occasionally.

On 9/8/2017 4:35 PM, Wes Stewart wrote:

> I am often puzzled by some of this advice. The K3S manual on page 30
> says among other things:
>
> "While speaking into the microphone in a
> normal voice, adjust MIC for a peak ALC
> meter indication of about 5-7 bars (see below)".
>
> Then regarding audio data modes it says on page 34:
>
> "If you’re using an audio-shift transmit mode (LSB,
> USB, DATA A, or AFSK A), you’ll need to set
> the MIC level while watching the ALC meter.
> You can use the same procedure outlined for voice
> modes (pg. 30), except that speech compression
> should not be used."
>
> So 5 to 7 bars seem to be indicated. Where does the '4 solid, fifth
> flashing come from'?
>
> This is particularly questionable with constant amplitude modes, where
> it doesn't matter whether there is ALC developed or not.
>
> Maybe someone can enlighten me.
>
> Wes N7WS
>
>
> On 9/8/2017 5:36 AM, Don Wilhelm wrote:
>> Bret,
>>
>> This is a condition we call "Power Hunting", and it usually indicates
>> that you do not have the audio level set correctly for Elecraft
>> transceivers.
>>
>> Are you driving the audio to illuminate 4 bars on the K3S ALC meter
>> with the 5th bar flashing? You must operate Elecraft gear differently
>> than other transceivers because of the closed loop system used for
>> power control is different than the simplistic "control the drive
>> level" system that other transceivers use.
>>
>> Ignore the internet (and WSJT-X) advice which tells you to adjust the
>> power with the audio level and set the power to maximum.
>>
>> With Elecraft gear, set the audio as instructed in the manual and
>> adjust the power with the POWER knob.
>>
>> 73,
>> Don W3FPR
>
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--
R. Kevin Stover AC0H
FISTS #11993
SKCC #215
NAQCC #3441
ARRL
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Bob McGraw - K4TAX

Re: Adjusting Audio Level for Digital Modes

In reply to this post by Mike Harris-9

That works too.

73

Bob, K4TAX

On 9/9/2017 6:44 AM, Mike Harris wrote:

> How about using the mouse scroll wheel, it adjusts the power in 0.1dB
> steps. At least it does on my Win7 box.
>
> The waterfall sliders also respond to the scroll wheel.
>
> Regards,
>
> Mike VP8NO
>
> On 08/09/2017 21:52, Bob McGraw K4TAX wrote:
>> As an operational note for WSJT-X. Version 1.8.0 -rc2
>>
>> To adjust the audio level via the software slider marked *Pwr* on the
>> right, I find it more precise to place the cursor just above or just
>> below the slider bar, depending which way you wish the audio level to
>> go, and click the left mouse button one time. This will move the
>> slider to the next step. I find this to be easier than placing the
>> cursor on the slider and trying to move it up or down.
> How about using the mouse scroll
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
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