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K3 SSB +CW Power Overshoot

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K3 SSB +CW Power Overshoot

I have just attempted the K3 SSB +CW configuration for the first time.
Unfortunately, behavior is not quite as expected; I experience a
substantial CW carrier overshoot on first key press and after a subsequent
mode change. (Mode change can be a band change or an Operate/Standby
change when running with the KPA500).

The overshoot is on the order of 10 to 40% depending on the power level
setting.

When running the K3 barefoot at 100 watts the overshoot is on the order of
110 watts measured with a W2 in peak reading mode.

When running the KPA500 set for 500 watts (approx 27 watts drive), the KPA
output overshoot has been observed to exceed 700 watts triggering a high
power fault. The only recourse is to reduce drive setting to the KPA500 to
an output level of 400 watts or so where the output power overshoots to on
the order of 550 watts.

Holding down the key after the overshoot, the power settles to the selected
value in a second or so (assuming KPA power is set such that no fault
occurs).

Subsequent CW key presses produce power output at the selected value without
overshoot, regardless of momentary or continuous key press.

Also observed is difficulty setting power on key down, particularly with the
KPA500. Power setting is "jumpy" when changing power, after the overshoot
has stabilized. It seems as if when increasing power, it overshoots the set
value, then drops to the set value.

The issue is observed on all bands and on upper or lower sideband.

I've performed TX Power Calibrate several times with reported success, but
no change in overshoot behavior.

When in normal CW mode, there is no overshoot and the power adjustment is
smooth and stable.

The SSB +CW mode would be quite useful if it was stable, but I am uneasy
using it as currently implemented. Any comments or ideas are welcome.

K3 is S/N 4457
Firmware version is 5.62
FPF 1.26
DSP 2.88

73,
Dan AC6DM

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Josh Fiden

Re: K3 SSB +CW Power Overshoot

What is "SSB+CW mode"?

73,
Josh W6XU

Sent from my mobile device

> On May 28, 2018, at 9:44 AM, Dan Maase via Elecraft <[hidden email]> wrote:
>
>
> I have just attempted the K3 SSB +CW configuration for the first time.
> Unfortunately, behavior is not quite as expected; I experience a
> substantial CW carrier overshoot on first key press and after a subsequent
> mode change. (Mode change can be a band change or an Operate/Standby
> change when running with the KPA500).
>
> The overshoot is on the order of 10 to 40% depending on the power level
> setting.
>
> When running the K3 barefoot at 100 watts the overshoot is on the order of
> 110 watts measured with a W2 in peak reading mode.
>
> When running the KPA500 set for 500 watts (approx 27 watts drive), the KPA
> output overshoot has been observed to exceed 700 watts triggering a high
> power fault. The only recourse is to reduce drive setting to the KPA500 to
> an output level of 400 watts or so where the output power overshoots to on
> the order of 550 watts.
>
> Holding down the key after the overshoot, the power settles to the selected
> value in a second or so (assuming KPA power is set such that no fault
> occurs).
>
> Subsequent CW key presses produce power output at the selected value without
> overshoot, regardless of momentary or continuous key press.
>
> Also observed is difficulty setting power on key down, particularly with the
> KPA500. Power setting is "jumpy" when changing power, after the overshoot
> has stabilized. It seems as if when increasing power, it overshoots the set
> value, then drops to the set value.
>
> The issue is observed on all bands and on upper or lower sideband.
>
> I've performed TX Power Calibrate several times with reported success, but
> no change in overshoot behavior.
>
> When in normal CW mode, there is no overshoot and the power adjustment is
> smooth and stable.
>
> The SSB +CW mode would be quite useful if it was stable, but I am uneasy
> using it as currently implemented. Any comments or ideas are welcome.
>
> K3 is S/N 4457
> Firmware version is 5.62
> FPF 1.26
> DSP 2.88
>
> 73,
> Dan AC6DM
>
> ______________________________________________________________
> 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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Elecraft mailing list

Re: K3 SSB +CW Power Overshoot

Josh:

This configuration permits sending SSB as well as CW in one mode (SSB). CW frequency is offset from SSB frequency by the value of configured CW tone?
This is sometimes called "cross-mode" in non-Elecraft nomenclature.
Useful to continue a SSB conversation of QSB reduces intelligibility.
Also can check configured power with a key press without messing with "Tune" setting.

73,
Dan
AC6DM

What is "SSB+CW mode"?

73,
Josh W6XU

Sent from my mobile device

K8TE

Re: K3 SSB +CW Power Overshoot

In reply to this post by Elecraft mailing list

Dan,

I experienced a similar issue with my K3, S/N range 4,000. I attempted a TX
Gain calibration with minimal improvement. 40m and higher bands (in
frequency) worked OK (no overshoot) while lower bands still faulted.

I finally performed an EE INIT, reloaded 5.60 firmware, and the last saved
configuration. I later upgraded to the beta 5.64 firmware. Neither
firmware version resulted in overshoot after the EE INIT. The rig has
operated normally over the last week. I can now rest without worries (about
the K3 and its performance at the upcoming FD).

Save your current K3 configuration and try an EE INIT. While not logical, I
did this twice before I achieved success. GL!

73, Bill, K8TE

--
Sent from: http://elecraft.365791.n2.nabble.com/
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Josh Fiden

Re: K3 SSB +CW Power Overshoot

In reply to this post by Elecraft mailing list

Interesting! Sounds useful on 6m, for example, when running a contest SSB above 125 and there's a difficult Q where the guy's having trouble with an exchange element. Generally running an amp, so overshoot would be a problem.

Thanks for info.

73
Josh W6XU

Sent from my mobile device

> On May 28, 2018, at 11:41 AM, Dan Maase <[hidden email]> wrote:
>
>
> Josh:
>
> This configuration permits sending SSB as well as CW in one mode (SSB). CW frequency is offset from SSB frequency by the value of configured CW tone?
> This is sometimes called "cross-mode" in non-Elecraft nomenclature.
> Useful to continue a SSB conversation of QSB reduces intelligibility.
> Also can check configured power with a key press without messing with "Tune" setting.
>
> 73,
> Dan
> AC6DM
>
> What is "SSB+CW mode"?
>
> 73,
> Josh W6XU
>
> Sent from my mobile device
>
> > On May 28, 2018, at 9:44 AM, Dan Maase via Elecraft <[hidden email]> wrote:
> >
> >
> > I have just attempted the K3 SSB +CW configuration for the first time.
> > Unfortunately, behavior is not quite as expected; I experience a
> > substantial CW carrier overshoot on first key press and after a subsequent
> > mode change. (Mode change can be a band change or an Operate/Standby
> > change when running with the KPA500).
> >
> > The overshoot is on the order of 10 to 40% depending on the power level
> > setting.
> >
> > When running the K3 barefoot at 100 watts the overshoot is on the order of
> > 110 watts measured with a W2 in peak reading mode.
> >
> > When running the KPA500 set for 500 watts (approx 27 watts drive), the KPA
> > output overshoot has been observed to exceed 700 watts triggering a high
> > power fault. The only recourse is to reduce drive setting to the KPA500 to
> > an output level of 400 watts or so where the output power overshoots to on
> > the order of 550 watts.
> >
> > Holding down the key after the overshoot, the power settles to the selected
> > value in a second or so (assuming KPA power is set such that no fault
> > occurs).
> >
> > Subsequent CW key presses produce power output at the selected value without
> > overshoot, regardless of momentary or continuous key press.
> >
> > Also observed is difficulty setting power on key down, particularly with the
> > KPA500. Power setting is "jumpy" when changing power, after the overshoot
> > has stabilized. It seems as if when increasing power, it overshoots the set
> > value, then drops to the set value.
> >
> > The issue is observed on all bands and on upper or lower sideband.
> >
> > I've performed TX Power Calibrate several times with reported success, but
> > no change in overshoot behavior.
> >
> > When in normal CW mode, there is no overshoot and the power adjustment is
> > smooth and stable.
> >
> > The SSB +CW mode would be quite useful if it was stable, but I am uneasy
> > using it as currently implemented. Any comments or ideas are welcome.
> >
> > K3 is S/N 4457
> > Firmware version is 5.62
> > FPF 1.26
> > DSP 2.88
> >
> > 73,
> > Dan AC6DM
> >
>
>
>

Elecraft mailing list

Re: K3 SSB +CW Power Overshoot

In reply to this post by Elecraft mailing list

Bill:
Thanks for your input. I did EEINIT yesterday and reloaded all SW. No
change.

Today, I did EEINIT again and fooled around with the radio in its native
state, changing modes, etc.
Then reloaded saved configuration and for no particular reason, did a BSET.
Then did a SSB +CW selection. Lo and behold, the CW behavior is what I would
expect and same as in basic CW mode.
No overshoot and power change is smooth with no jumps. On CW key press,
power starts out slightly low and builds to the set value.

I suspect there is a bug in the code somewhere. Experience says there is probably an
uninitialized variable lurking in the ALC code. **Elecraft SW developers note.**
It will be interesting to see if this good behavior sticks.

BTW, Albuquerque is my old, old stomping ground. BSEE from UNM in 1967.

73,
Dan AC6DM

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Elecraft mailing list

Re: K3 SSB +CW Power Overshoot

In reply to this post by Elecraft mailing list

An afternoon of operating SSB a bit and the CW overshoot behavior has
returned. No joy. Hope this gets on the Elecraft bug list.

73,
Dan
AC6DM

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