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

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MaverickNH

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

I'm learning about a new KPA500/KAT500 installed with my K3S. When I have the
K3S power knob set, in this case, to show 420-440W peak-hold as read on the
KPA500 LED screen, I see the KPA500 SWR showing 1-3 LEDs lit (it may stay at
1 LED or climb from 1 to 3 LEDs over 15sec TX, always below 1.5), the KAT500
with SWR 1.2 LED lit, and P3TXMON indicating SWR 1.00 (it might start at
1.15 and settle back to 1.00 over 15sec TX). But PEP on the P3TXMON can
range from 10-15W up to ~400W on successive 15sec periods of TX using WSJT-X
FT8 (going for very distant CQs). Adjusting the K3S power knob down may
bring P3TXMON displayed power up if its 10-15W. If the P3TXMON shows 200W
adjusting the K3S power knob up may bring the P3TXMON power shown down.

Is that how it's supposed to work?

I have a P3TXMON 2000W 1.8-54MHz unit installed on my feedline at the rig as
follows: KAT500 to Common Mode Choke to P3TXMON to Bias-T to SG-235 remote
ATU at antenna base to 43ft Vertical antenna, with some Lightning GDTs
between at antenna base and home feedline entrance. My tuning practice is to
change Frequency, turn KAT500 to BYP, tune the remote ATU, then set KAT500
to AUTO and let it adjust on 1st TX.

Bret/N4SRN

--
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Jack Brindle-2

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

The three units are taking widely different measurements. The KPA500 measures the signals it sees going into the KAT500,
while the KAT500 measures what it sees going into the choke. Finally, the P3TXMON’s coupler measures what it
sees going into the coax going to the SG-235. It is quite probable they will actually see different things. To make matters
worse, you are trying to take measurements with a varying signal.

You really want to step back and make the measurements with a steady signal (CW, key down) to see what is really happening.
But when you do, be aware of what is happening in the SG-235. While the SGC literature says it is rated for 500W SSB, the important
line says only 200W continuous. That means at 500W there is quite about of heating occurring in the toroid cores in the tuner. They
won’t have much of any time to cool down between transmissions (SSB has very low peak to off times). Much of this and you will
see the P3TXMon and KAT500 reading skyrocket and then will send the SGC in for repairs.

If you intend to keep this setup, dial the K3S power down so that the SGC really only sees 200 watts, test everything at that level, then
don’t change power levels when you switch to the digital mode. Also, you might want to move the choke to the output side of the
P3TXMon pickup unit.The choke is designed to clear up currents on the outside of the coax shield (which you don’t want for
reasons others will most likely explain). You are exposing the P3TXMON to these currents and probably adversely affecting
its measurements. Make that change and the P3TXMON and KAT500 readings should become a bit closer.

And remember to do all this at CW. Taking measurements with a varying signal can introduce interesting issues in
the measurements themselves. The issue has to do with when the two signals (forward and reflected voltage) are actually
measured. Unless they are simultaneously measured, then you won’t get precise values unless the signal is steady-state.
I suspect you are running into a bit of this also.

- Jack, W6FB

> On Sep 4, 2017, at 5:06 AM, MaverickNH <[hidden email]> wrote:
>
> I'm learning about a new KPA500/KAT500 installed with my K3S. When I have the
> K3S power knob set, in this case, to show 420-440W peak-hold as read on the
> KPA500 LED screen, I see the KPA500 SWR showing 1-3 LEDs lit (it may stay at
> 1 LED or climb from 1 to 3 LEDs over 15sec TX, always below 1.5), the KAT500
> with SWR 1.2 LED lit, and P3TXMON indicating SWR 1.00 (it might start at
> 1.15 and settle back to 1.00 over 15sec TX). But PEP on the P3TXMON can
> range from 10-15W up to ~400W on successive 15sec periods of TX using WSJT-X
> FT8 (going for very distant CQs). Adjusting the K3S power knob down may
> bring P3TXMON displayed power up if its 10-15W. If the P3TXMON shows 200W
> adjusting the K3S power knob up may bring the P3TXMON power shown down.
>
> Is that how it's supposed to work?
>
> I have a P3TXMON 2000W 1.8-54MHz unit installed on my feedline at the rig as
> follows: KAT500 to Common Mode Choke to P3TXMON to Bias-T to SG-235 remote
> ATU at antenna base to 43ft Vertical antenna, with some Lightning GDTs
> between at antenna base and home feedline entrance. My tuning practice is to
> change Frequency, turn KAT500 to BYP, tune the remote ATU, then set KAT500
> to AUTO and let it adjust on 1st TX.
>
> Bret/N4SRN
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> ______________________________________________________________
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MaverickNH

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

David Bunte

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

In reply to this post by MaverickNH

Bret -

W6FB - Jack, was spot on with his information regarding the differing
readings... but I have an added question. If your SGC-235 gives an
acceptable match, then why use the KAT500 at all? I think that it is seldom
a good idea to use two antenna tuners in series... at least that has been
my thinking for the past 60 years. Am I missing something.

I have a K3, P3, KPA500 & KAT500... but also have a hi power remote tuner
at the base of my vertical. My KAT500 is bypassed, UNLESS I have a failure
in my remote tuner, in which case I can bypass it, and quickly switch to
the KAT500.

If there is a compelling reason to run both tuners I could try that, but
thought that was ill advised.

Very 73 de Dave - K9FN

On Mon, Sep 4, 2017 at 8:06 AM, MaverickNH <[hidden email]> wrote:

> I'm learning about a new KPA500/KAT500 installed with my K3S. When I have
> the
> K3S power knob set, in this case, to show 420-440W peak-hold as read on the
> KPA500 LED screen, I see the KPA500 SWR showing 1-3 LEDs lit (it may stay
> at
> 1 LED or climb from 1 to 3 LEDs over 15sec TX, always below 1.5), the
> KAT500
> with SWR 1.2 LED lit, and P3TXMON indicating SWR 1.00 (it might start at
> 1.15 and settle back to 1.00 over 15sec TX). But PEP on the P3TXMON can
> range from 10-15W up to ~400W on successive 15sec periods of TX using
> WSJT-X
> FT8 (going for very distant CQs). Adjusting the K3S power knob down may
> bring P3TXMON displayed power up if its 10-15W. If the P3TXMON shows 200W
> adjusting the K3S power knob up may bring the P3TXMON power shown down.
>
> Is that how it's supposed to work?
>
> I have a P3TXMON 2000W 1.8-54MHz unit installed on my feedline at the rig
> as
> follows: KAT500 to Common Mode Choke to P3TXMON to Bias-T to SG-235 remote
> ATU at antenna base to 43ft Vertical antenna, with some Lightning GDTs
> between at antenna base and home feedline entrance. My tuning practice is
> to
> change Frequency, turn KAT500 to BYP, tune the remote ATU, then set KAT500
> to AUTO and let it adjust on 1st TX.
>
> Bret/N4SRN
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> ______________________________________________________________
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> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>

Bob McGraw - K4TAX

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

I wholly agree. Every tuner placed in line has loss, two have twice or
more the loss. I rather deal with a bit of SWR. The loss in the line
due to any amount of SWR on the line does not change with the use of a
tuner.

Of course the tuner makes the radio and its operator seem more satisfied
then all is well. Match the line to the load and don't worry about it.

73

Bob, K4TAX

On 9/4/2017 11:36 AM, David Bunte wrote:

> Bret -
>
> W6FB - Jack, was spot on with his information regarding the differing
> readings... but I have an added question. If your SGC-235 gives an
> acceptable match, then why use the KAT500 at all? I think that it is seldom
> a good idea to use two antenna tuners in series... at least that has been
> my thinking for the past 60 years. Am I missing something.
>
> I have a K3, P3, KPA500 & KAT500... but also have a hi power remote tuner
> at the base of my vertical. My KAT500 is bypassed, UNLESS I have a failure
> in my remote tuner, in which case I can bypass it, and quickly switch to
> the KAT500.
>
> If there is a compelling reason to run both tuners I could try that, but
> thought that was ill advised.
>
>
> Very 73 de Dave - K9FN
>
>
>
> On Mon, Sep 4, 2017 at 8:06 AM, MaverickNH <[hidden email]> wrote:
>
>> I'm learning about a new KPA500/KAT500 installed with my K3S. When I have
>> the
>> K3S power knob set, in this case, to show 420-440W peak-hold as read on the
>> KPA500 LED screen, I see the KPA500 SWR showing 1-3 LEDs lit (it may stay
>> at
>> 1 LED or climb from 1 to 3 LEDs over 15sec TX, always below 1.5), the
>> KAT500
>> with SWR 1.2 LED lit, and P3TXMON indicating SWR 1.00 (it might start at
>> 1.15 and settle back to 1.00 over 15sec TX). But PEP on the P3TXMON can
>> range from 10-15W up to ~400W on successive 15sec periods of TX using
>> WSJT-X
>> FT8 (going for very distant CQs). Adjusting the K3S power knob down may
>> bring P3TXMON displayed power up if its 10-15W. If the P3TXMON shows 200W
>> adjusting the K3S power knob up may bring the P3TXMON power shown down.
>>
>> Is that how it's supposed to work?
>>
>> I have a P3TXMON 2000W 1.8-54MHz unit installed on my feedline at the rig
>> as
>> follows: KAT500 to Common Mode Choke to P3TXMON to Bias-T to SG-235 remote
>> ATU at antenna base to 43ft Vertical antenna, with some Lightning GDTs
>> between at antenna base and home feedline entrance. My tuning practice is
>> to
>> change Frequency, turn KAT500 to BYP, tune the remote ATU, then set KAT500
>> to AUTO and let it adjust on 1st TX.
>>
>> Bret/N4SRN
>>
>>
>>
>> --
>> Sent from: http://elecraft.365791.n2.nabble.com/
>> ______________________________________________________________
>> 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
>> Message delivered to [hidden email]
>>
> ______________________________________________________________
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>
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> Message delivered to [hidden email]
>

Jim Brown-10

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

On 9/4/2017 9:43 AM, Bob McGraw K4TAX wrote:
> I rather deal with a bit of SWR. The loss in the line due to any
> amount of SWR on the line does not change with the use of a tuner.

There's another important issue that K6XX (engineer at Elecraft) alerted
me to. The distortion in an output stage increases if it is poorly
matched to its load. Bob is my neighbor and we're both serious
contesters. When I moved here, he made sure that I knew that, and that I
kept my tube amp well tuned. Solid state amps mostly don't have tunable
output networks, so the antenna tuner must provide that match.

73, Jim K9YC

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Bill Frantz

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

In reply to this post by Bob McGraw - K4TAX

Of course Bob meant when the tuner is located at the
transmitter. When the tuner/matching network is located at the
antenna feed point, the SWR of the line changes and so do the
line losses.

73 Bill AE6JV

On 9/4/17 at 9:43 AM, [hidden email] (Bob McGraw K4TAX) wrote:

>I rather deal with a bit of SWR. The loss in the line due to
>any amount of SWR on the line does not change with the use of
>a tuner.

-----------------------------------------------------------------------
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Bob McGraw - K4TAX

OT --K3S/KPA500/KAT500 - Adjusting TX Power

I'll speculate that most hams today have a tuner at the station
location, while very few have tuners located at the load.    The load
being the point where the coax or balanced line is attached or is
feeding the radiating device.   That being the case with the tuner at
the load, then SWR on the line does not change with the use of a
tuner.   Only when the tuner is located at the load does the SWR on the
line become nil and thus the line is operating at minimum loss or in a
matched condition.

73

Bob, K4TAX

On 9/4/2017 4:39 PM, Bill Frantz wrote:
> Of course Bob meant when the tuner is located at the transmitter. When
> the tuner/matching network is located at the antenna feed point, the
> SWR of the line changes and so do the line losses.
>
> 73 Bill AE6JV

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MaverickNH

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

In reply to this post by David Bunte

David Bunte

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

Bret -

I recall hearing that as well. That has not been my experience. My antenna
presents a real challenge on some bands, but right now, for example, on
14.019 I have 1.34:1 indicated SWR in the shack at about 20 watts tune
power. Key down with the KPA500 in line, showing power of 585 watts and the
SWR holding steady at 1.34:1.

If I put my remote tuner in ByPass, and use my KAT500, I am seeing the SWR
at 1.28:1, whether at 20 watts, or at 500 watts. But, I will gladly use the
remote tuner which is right at the base of my 30' Flag Pole Vertical. It is
not a big deal on some bands, but with 125' of LMR400 coax, there is more
loss on a few bands than I want to give away. I cannot tune this antenna on
160 with the KAT500, because impedance is WAY too low, and the native SWR
is 'out of sight'. The KAT500 is an awesome tuner, but nowhere near up to
that task.

My remote tuner will make the rig happy on 160, but my antenna is so short
for 160 that many folks think I am crazy to even try it, but I never
claimed to not be crazy... I just keep on having fun.

Best of luck,

Dave - K9FN

On Mon, Sep 4, 2017 at 6:36 PM, Charles <[hidden email]> wrote:

> You are very likely right David. If my rATU gets me down below 1.5 I will
> bypass the KAT500. I do recall reading somewhere that a near 1:1 SWR at low
> tune-up power can be higher at TX levels but I'm not sure about by how much
> higher.
>
> Best regards,
>
> Bret
>
> aka Charles Jessee N4SRN
>
>
> ------ Original Message ------
>
> *From: *David Bunte
> *To: *Charles Bret Jessee
> *Cc: *[hidden email]
> *Sent: *September 4, 2017 at 12:36 PM
> *Subject: *Re: [Elecraft] [KPA500] K3S/KPA500/KAT500 - Adjusting TX Power
>
> Bret -
>
> W6FB - Jack, was spot on with his information regarding the differing
> readings... but I have an added question. If your SGC-235 gives an
> acceptable match, then why use the KAT500 at all? I think that it is seldom
> a good idea to use two antenna tuners in series... at least that has been
> my thinking for the past 60 years. Am I missing something.
>
> I have a K3, P3, KPA500 & KAT500... but also have a hi power remote tuner
> at the base of my vertical. My KAT500 is bypassed, UNLESS I have a failure
> in my remote tuner, in which case I can bypass it, and quickly switch to
> the KAT500.
>
> If there is a compelling reason to run both tuners I could try that, but
> thought that was ill advised.
>
>
> Very 73 de Dave - K9FN
>
>
>
> On Mon, Sep 4, 2017 at 8:06 AM, MaverickNH <[hidden email]> wrote:
>
>> I'm learning about a new KPA500/KAT500 installed with my K3S. When I have
>> the
>> K3S power knob set, in this case, to show 420-440W peak-hold as read on
>> the
>> KPA500 LED screen, I see the KPA500 SWR showing 1-3 LEDs lit (it may stay
>> at
>> 1 LED or climb from 1 to 3 LEDs over 15sec TX, always below 1.5), the
>> KAT500
>> with SWR 1.2 LED lit, and P3TXMON indicating SWR 1.00 (it might start at
>> 1.15 and settle back to 1.00 over 15sec TX). But PEP on the P3TXMON can
>> range from 10-15W up to ~400W on successive 15sec periods of TX using
>> WSJT-X
>> FT8 (going for very distant CQs). Adjusting the K3S power knob down may
>> bring P3TXMON displayed power up if its 10-15W. If the P3TXMON shows 200W
>> adjusting the K3S power knob up may bring the P3TXMON power shown down.
>>
>> Is that how it's supposed to work?
>>
>> I have a P3TXMON 2000W 1.8-54MHz unit installed on my feedline at the rig
>> as
>> follows: KAT500 to Common Mode Choke to P3TXMON to Bias-T to SG-235
>> remote
>> ATU at antenna base to 43ft Vertical antenna, with some Lightning GDTs
>> between at antenna base and home feedline entrance. My tuning practice is
>> to
>> change Frequency, turn KAT500 to BYP, tune the remote ATU, then set KAT500
>> to AUTO and let it adjust on 1st TX.
>>
>> Bret/N4SRN
>>
>>
>>
>> --
>> Sent from: http://elecraft.365791.n2.nabble.com/
>> ______________________________________________________________
>> 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
>> Message delivered to [hidden email]
>>
>
>

MaverickNH

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

MaverickNH

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

In reply to this post by MaverickNH

Adjusting power still has me stymied. Oddly, once set and TXing WSJT-X FT8
15sec cycles, it creeps up from 180-200W on the KPA500 readout towards 270W.
The P3TXMON reads lower but creeps up over 200W on successive TX cycles as
well.

I moved my components around as suggested so the TX feed is now K3S to
KPA500 to KAT500 (on BYPASS if SWR is already low from remote ATU at antenna
base) to Common Mode Choke to P3TXMON to Bias-T (for rATU DC over coax) and
out of the house. From there it goes through a Lightning Protector GDT,
another toroid choke, a long stretch of buried RG213 to base of 43ft
Vertical Antenna, through another GDT and choke, to SG-235 rATU and finally
to antenna mast.

Bret/N4SRN

--
Sent from: http://elecraft.365791.n2.nabble.com/
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Don Wilhelm

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

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

On 9/8/2017 7:46 AM, MaverickNH wrote:
> Adjusting power still has me stymied. Oddly, once set and TXing WSJT-X FT8
> 15sec cycles, it creeps up from 180-200W on the KPA500 readout towards 270W.
> The P3TXMON reads lower but creeps up over 200W on successive TX cycles as
> well.
>
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Bob McGraw - K4TAX

Adjusting Audio Level for Digital Modes

Don is absolutely correct on his earlier points.   The K3S setup and
operation does not follow the suggestions for setting the audio levels
as other radios and as described in the WSJT-X user information.

In DATA mode, it is my view that A L C stands for AUDIO LEVEL CREST.
i.e. the highest point, level or degree. It does not, in my terms,
stand for Automatic Level Control as understood by many and as used on
many other radio brands.   Although, in SSB mode, the the normal
convention of understanding with ALC does apply.

With regard to WSJT-X, there is provision, in the AUDIO tab to have the
levels remembered by band for Transmit and Tune.   I find with these
boxes checked things work quite well. Just remember that the transmit
data level can or will be different than the tune level. Thus some
minor adjustment of the PWR slider in the software may be needed between
TUNE and TRANSMIT. Once done, all other things remaining static, the
power from band to band and day to day remain precise as one desires.

In my measurements, in DATA A mode with a single tone applied, I find
that any audio level where the A L C indication {AUDIO LEVEL CREST} is
less than 4 bars will allow the power control circuit in the radio to
"hunt". The result will be observed as a slow power increase.

I'm stubborn, hard-headed and have used many other brands and models of
radios in the past. As I've said before, I had to learn to use the K3S
as it is intended, thus it is not like other radios in this respect.
Once done, you'll be much more satisfied with its outstanding performance.

73

Bob, K4TAX

K3S s/n 10163

On 9/8/2017 7:36 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
>

Don Wilhelm

Re: Adjusting Audio Level for Digital Modes

Bob and all,

Lyle Johnson (the DSP designer) has stated several times that actual ALC
begins at the 5th bar on the "ALC" meter. That is the point of "Zero
ALC" for the K3/K3S/KX3/KX2.

The K2 is different in its indication in that the ALC begins at the 1st
bar illuminated. The data mode setup for the K2 is the same - set the
audio level correctly and control the power with the power knob.
So for the K2, you advance the audio until you begin the see the 1st ALC
bar illuminated and then back off until it goes out.

73,
Don W3FPR

On 9/8/2017 2:41 PM, Bob McGraw K4TAX wrote:
> Don is absolutely correct on his earlier points. The K3S setup and
> operation does not follow the suggestions for setting the audio levels
> as other radios and as described in the WSJT-X user information.
>
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Wes Stewart-2

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

In reply to this post by Don Wilhelm

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

Don Wilhelm

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

Wes,

That information comes from the DSP designer who has on several
occassions stated that the onset of ALC is at the 5th bar.
He has indicated that from the time of K3 Firmware Field Test.

Why that information is not in the K3 and K3S manuals is a mystery to
me. It is present in the KX3 manual.

73,
Don W3FPR

On 9/8/2017 5:35 PM, Wes Stewart wrote:

Joe Subich, W4TV-4

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

In reply to this post by Wes Stewart-2

> So 5 to 7 bars seem to be indicated. Where does the '4 solid, fifth
> flashing come from'?

As explained by Wayne and Lyle several years ago, in data modes the
ALC meter scale is shifted so that any display below four bars shows
*audio input level* below the nominal operating point (whatever point
below the ALC clipping level Lyle set to allow headroom) while five
bars or more represents ALC action.

In data modes (DATA A, AFSK A), the DSP algorithm will *increase* the
audio gain (effectively increase the mic/line in level) as needed to
provide sufficient audio drive for the DSP to work correctly (generate
the nominal signal level prior to the ALC/Power setting routine).

73,

... Joe, W4TV

On 9/8/2017 5:35 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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MaverickNH

Re: Adjusting Audio Level for Digital Modes

In reply to this post by Bob McGraw - K4TAX

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

--
Sent from: http://elecraft.365791.n2.nabble.com/
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Don Wilhelm

Re: Adjusting Audio Level for Digital Modes

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

On 9/8/2017 6:36 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
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> ______________________________________________________________
> Elecraft mailing list
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>
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>