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K3 - SPE Expert 1K-FA and ALC

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LA8AW

K3 - SPE Expert 1K-FA and ALC

All,

Here is the statement from the developer of the SPE Expert 1K-FA - regarding
ALC, quoted from an early Expert Reflector:....

I hope this will clarify the SPE Expert vs K3 - and ALC !!

Please excuse me if I step on someones toes......

quote

*The Elecraft K3 had positive-going ALC, too. In helping them test their*
*conversion of the K3 to negative-going ALC with different amps, I received*
*an email from Gianfranco, copy below. His thoughts on how the SPE Expert
is*
*designed to handle transceiver drive may apply here to the Ten-Tec.*
*
*
*FWIW,*
*
*
*Bob*
*K5LLF*
*
*
*Hello Bob,*
*
*
*Elecraft has a strong reputation for manufacturing cost effective and*
*quality transceivers, and for this I'm glad that they decided to conform*
*with the state-of-the-art negative ALC how is commonly intended by all the*
*other manufacturers.*
*
*
*As you well know the ALC is a transceiver's input used to adjust its output
*
*power during transmission: at 0 Vdc there is a maximum power emission and,*
*little by little the control voltage decreases toward negative values,*
*output power emission is reduced until it becomes practically nothing at a*
*given BV (Break Voltage) control voltage.*
*
*
*Every brand has a different BV (ICOM: -3/-4 Vdc, YAESU: -4/-5 Vdc,*
*KENWOOD: -8/-9 Vdc; etc.).*
*
*
*In order to have the widest possible coverage, all the linear amplifiers'*
*manufacturers state that the maximum ALC voltage excursion sourced by their
*
*devices is -11 Vdc.*
*
*
*>From this perspective Elecraft's choice (0 Vdc: max PW; -4 Vdc: min PW)*
*sounds good then, but a very important detail to take into account is the*
*overall intervention time which has to be the shortest possible!*
*
*
*All the ordinary linear amplifiers have an external potentiometer which
sets*
*
*
*a given threshold (manually adjusted by the user) whose purpose is to avoid
*
*the linear amplifier's over-driving when that threshold is exceeded.*
*
*
*SPE EXPERT 1K-FA is quite different from those because is fully automatic*
*within its working: ALC control is not only for avoiding over-driving*
*situations, but it is also intended as a system for adjusting the optimal*
*output power for a perfect driving of the transceiver itself.*
*
*
*We really suggest to always leave the transceiver's output power manual*
*control to its maximum level because the EXPERT, thanks to its exclusive*
*design, will provide to control that level as long as the required optimal*
*value will be reached.*
*
*
*Don't try to analyse the ALC control voltage of our linear amplifier
because*
*it cannot be measured using ordinary methods as it operates dynamically for
*
*assuring a great linearity.*
*
*
*Elecraft has only to implement a very fast input able to deal with negative
*
*voltages as all the other manufacturers already do: SPE's amplifier will*
*adapt to that in order to work for the best possible linearity.*
*
*
*
*
*
*
*73's*
*
*
*Gianfranco I0ZY*

unquote

_____________________

73 de LA8AW - Odd-Egil
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W8JI

Re: K3 - SPE Expert 1K-FA and ALC

*We really suggest to always leave the transceiver's output
power manual*
*control to its maximum level because the EXPERT, thanks to
its exclusive*
*design, will provide to control that level as long as the
required optimal*
*value will be reached.*
*Elecraft has only to implement a very fast input able to
deal with negative
*voltages as all the other manufacturers already do: SPE's
amplifier will*
*adapt to that in order to work for the best possible
linearity.*

The ALC loop response can never be faster than group delay
through the transmitter chain. While I have never measured
the Elecraft filter, some crystal filters have a few mS
delay. The propagation through the rest of the circuitry
adds to the delay, as does the inevitable delay time in the
actual ALC system. All of those delays, from the ALC control
point forward to the ALC detection, and back from that point
to the AGC controlled stage, add together.

Elecraft did a VERY smart thing by having the ALC detection,
or at least part of the ALC detection, ahead of the narrow
filters and everything else. Running the radio full on and
relying on the amplifier ALC would undo this, and may not
bring the results assumed.

Not only that, running other radios full on and depending
100% on amplifier ALC is probably not a good idea either.
The less "stuff" between the power sampling point and the
gain controlled stage, the better off we are.

The whole reason some radios have overshoot is they run gain
wide open and depend on a detector at the antenna port to
reduce power, and the sum of delays from the gain controlled
stage to the antenna, through the detector, through a
comparator, and back to the gain controlled stage is what
causes the problem in the first place. Moving the detection
point out of the radio is never a benefit.

I can't think of a reason in the world to use the amplifier
ALC for anything other than a safety limit, especially with
a rig like the K3 that does gain control and ALC ahead of
the filters and components that cause most of the delay in
the ALC loop.

Can anyone else see why running the radio wide open and
using 100% external detection is a good idea?

73 Tom

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Bjorn

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by LA8AW

2010/4/22, LA8AW <[hidden email]>:

Here is the statement from the developer of the SPE Expert 1K-FA - regarding
> ALC, quoted from an early Expert Reflector:....
>
> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>
> *We really suggest to always leave the transceiver's output power manual*
> *control to its maximum level because the EXPERT, thanks to its exclusive*
> *design, will provide to control that level as long as the required
> optimal*
> *value will be reached.*

Has anyone actually measured the combination of a K3 and the SPE amp
connected and adjusted as suggested by SPE? I have run my setup without ALC,
but I am curious about the statement and what the real results are.

73 de Björn,
SM0MDG
SE0X
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W8JI

Re: K3 - SPE Expert 1K-FA and ALC

Elecraft has warned NOT to listen to that advice .

The K3 ALC could only get worse and misbehave when the slow
loop from an amplifier is added.

----- Original Message -----
From: "Björn Mohr" <[hidden email]>
To: <[hidden email]>
Sent: Saturday, May 15, 2010 7:25 AM
Subject: Re: [Elecraft] K3 - SPE Expert 1K-FA and ALC

2010/4/22, LA8AW <[hidden email]>:

Here is the statement from the developer of the SPE Expert
1K-FA - regarding

> ALC, quoted from an early Expert Reflector:....
>
> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>
> *We really suggest to always leave the transceiver's
> output power manual*
> *control to its maximum level because the EXPERT, thanks
> to its exclusive*
> *design, will provide to control that level as long as the
> required
> optimal*
> *value will be reached.*

Has anyone actually measured the combination of a K3 and the
SPE amp
connected and adjusted as suggested by SPE? I have run my
setup without ALC,
but I am curious about the statement and what the real
results are.

73 de Björn,
SM0MDG
SE0X
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Vic K2VCO

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by Bjorn

Sorry, with all due respect this is HORRIBLE advice.

I won't argue with those that say that the ALC should be connected for its protective
value. But it should not be depended on to control output level -- the exciter should be
adjusted to produce approximately the drive required for full output.

The SPE Expert may have an exclusive design, but it is not exclusive enough to include a
time machine so that it can know how loud the operator is planning to talk, and it doesn't
control the delay inherent in the exciter's ALC circuitry.

The result is guaranteed to be increased distortion.

On 5/15/2010 4:25 AM, Björn Mohr wrote:

> 2010/4/22, LA8AW<[hidden email]>:
>
>
> Here is the statement from the developer of the SPE Expert 1K-FA - regarding
>> ALC, quoted from an early Expert Reflector:....
>>
>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>
>> We really suggest to always leave the transceiver's output power manual control to
>> its maximum level because the EXPERT, thanks to its exclusive design, will provide to
>> control that level as long as the required optimal value will be reached.

DAVID M. Elliott

Re: K3 - SPE Expert 1K-FA and ALC

If increased distortion is guaranteed, why doesn't it show on the spectrum scope?

We are obviously missing something here.

73 de W6BK

On May 15, 2010, at 11:03 AM, Vic K2VCO wrote:

> Sorry, with all due respect this is HORRIBLE advice.
>
> I won't argue with those that say that the ALC should be connected for its protective
> value. But it should not be depended on to control output level -- the exciter should be
> adjusted to produce approximately the drive required for full output.
>
> The SPE Expert may have an exclusive design, but it is not exclusive enough to include a
> time machine so that it can know how loud the operator is planning to talk, and it doesn't
> control the delay inherent in the exciter's ALC circuitry.
>
> The result is guaranteed to be increased distortion.
>
> On 5/15/2010 4:25 AM, Björn Mohr wrote:
>> 2010/4/22, LA8AW<[hidden email]>:
>>
>>
>> Here is the statement from the developer of the SPE Expert 1K-FA - regarding
>>> ALC, quoted from an early Expert Reflector:....
>>>
>>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>>
>>> We really suggest to always leave the transceiver's output power manual control to
>>> its maximum level because the EXPERT, thanks to its exclusive design, will provide to
>>> control that level as long as the required optimal value will be reached.
>
>
> --
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
> ______________________________________________________________
> Elecraft mailing list
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> 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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Guy, K2AV

Re: K3 - SPE Expert 1K-FA and ALC

Because if you are using something you can measure, like two tone, the
gains are already set and steady. To measure leading edge distortions
before an AGC loop or loops bite and settle takes some pretty
expensive lab equipment, both before and after the transmitter/amp.
What you got?

It IS terrible advice.

73, Guy.

On Sat, May 15, 2010 at 4:25 PM, David M. Elliott
<[hidden email]> wrote:

> If increased distortion is guaranteed, why doesn't it show on the spectrum scope?
>
> We are obviously missing something here.
>
> 73 de W6BK
>
>
> On May 15, 2010, at 11:03 AM, Vic K2VCO wrote:
>
>> Sorry, with all due respect this is HORRIBLE advice.
>>
>> I won't argue with those that say that the ALC should be connected for its protective
>> value. But it should not be depended on to control output level -- the exciter should be
>> adjusted to produce approximately the drive required for full output.
>>
>> The SPE Expert may have an exclusive design, but it is not exclusive enough to include a
>> time machine so that it can know how loud the operator is planning to talk, and it doesn't
>> control the delay inherent in the exciter's ALC circuitry.
>>
>> The result is guaranteed to be increased distortion.
>>
>> On 5/15/2010 4:25 AM, Björn Mohr wrote:
>>> 2010/4/22, LA8AW<[hidden email]>:
>>>
>>>
>>> Here is the statement from the developer of the SPE Expert 1K-FA - regarding
>>>> ALC, quoted from an early Expert Reflector:....
>>>>
>>>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>>>
>>>> We really suggest to always leave the transceiver's output power manual control to
>>>> its maximum level because the EXPERT, thanks to its exclusive design, will provide to
>>>> control that level as long as the required optimal value will be reached.
>>
>>
>> --
>> Vic, K2VCO
>> Fresno CA
>> http://www.qsl.net/k2vco/
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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>

k6rb

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by Vic K2VCO

I agree with Guy and Vic. It is not good to load up an amp and use AGC to
tamp it down. Lord knows there are enough bad sounding stations already on
the air, especially on sideband.

Rob K6RB

----- Original Message -----
From: "Vic K2VCO" <[hidden email]>
To: <[hidden email]>
Sent: Saturday, May 15, 2010 11:03 AM
Subject: Re: [Elecraft] K3 - SPE Expert 1K-FA and ALC

Sorry, with all due respect this is HORRIBLE advice.

I won't argue with those that say that the ALC should be connected for its
protective
value. But it should not be depended on to control output level -- the
exciter should be
adjusted to produce approximately the drive required for full output.

The SPE Expert may have an exclusive design, but it is not exclusive enough
to include a
time machine so that it can know how loud the operator is planning to talk,
and it doesn't
control the delay inherent in the exciter's ALC circuitry.

The result is guaranteed to be increased distortion.

On 5/15/2010 4:25 AM, Björn Mohr wrote:

> 2010/4/22, LA8AW<[hidden email]>:
>
>
> Here is the statement from the developer of the SPE Expert 1K-FA -
> regarding
>> ALC, quoted from an early Expert Reflector:....
>>
>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>
>> We really suggest to always leave the transceiver's output power manual
>> control to
>> its maximum level because the EXPERT, thanks to its exclusive design,
>> will provide to
>> control that level as long as the required optimal value will be reached.

--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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DAVID M. Elliott

Re: K3 - SPE Expert 1K-FA and ALC

In general, I would agree with You and Guy and Vic.

However, Gianfranco of SPE (Expert) suggests running the exciter at full power. He says there is no splatter and the proof of the pudding is in the eating. That seems to be true. I can't see any splatter on the WaveNode and several on the air tests report fine audio with no splatter.

I repeat: There is something here we don't understand.

Any comment, Gianfranco?

73 de W6BK

73 de W6BK
On May 15, 2010, at 2:13 PM, Rob wrote:

> I agree with Guy and Vic. It is not good to load up an amp and use AGC to
> tamp it down. Lord knows there are enough bad sounding stations already on
> the air, especially on sideband.
>
> Rob K6RB
>
> ----- Original Message -----
> From: "Vic K2VCO" <[hidden email]>
> To: <[hidden email]>
> Sent: Saturday, May 15, 2010 11:03 AM
> Subject: Re: [Elecraft] K3 - SPE Expert 1K-FA and ALC
>
>
> Sorry, with all due respect this is HORRIBLE advice.
>
> I won't argue with those that say that the ALC should be connected for its
> protective
> value. But it should not be depended on to control output level -- the
> exciter should be
> adjusted to produce approximately the drive required for full output.
>
> The SPE Expert may have an exclusive design, but it is not exclusive enough
> to include a
> time machine so that it can know how loud the operator is planning to talk,
> and it doesn't
> control the delay inherent in the exciter's ALC circuitry.
>
> The result is guaranteed to be increased distortion.
>
> On 5/15/2010 4:25 AM, Björn Mohr wrote:
>> 2010/4/22, LA8AW<[hidden email]>:
>>
>>
>> Here is the statement from the developer of the SPE Expert 1K-FA -
>> regarding
>>> ALC, quoted from an early Expert Reflector:....
>>>
>>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>>
>>> We really suggest to always leave the transceiver's output power manual
>>> control to
>>> its maximum level because the EXPERT, thanks to its exclusive design,
>>> will provide to
>>> control that level as long as the required optimal value will be reached.
>
>
> --
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
> ______________________________________________________________
> 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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> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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Vic K2VCO

Re: K3 - SPE Expert 1K-FA and ALC

Any time the gain of the system changes, there's distortion. In SSB mode, I would expect
it to occur when the ALC voltage changes, such as at the beginning of syllables, etc.

On 5/15/2010 3:10 PM, David M. Elliott wrote:

> In general, I would agree with You and Guy and Vic.
>
> However, Gianfranco of SPE (Expert) suggests running the exciter at full power. He
> says there is no splatter and the proof of the pudding is in the eating. That seems to
> be true. I can't see any splatter on the WaveNode and several on the air tests report
> fine audio with no splatter.
>
> I repeat: There is something here we don't understand.
>
> Any comment, Gianfranco?

juergen piezo

Re: K3 - SPE Expert 1K-FA and ALC

Hi Vic

Yup, ALC is not feedforward correction system. It is a servo like mechanism that corrects after the distortion has left, then it corrects. For SSB splatter this is a disaster which we dont need.

The worst example of this is the Yaesu Quadra, it is the worst buckshot generator on the bands. The Quadra when used with ALC is an horrendous splatter generator.

Closing the stable door after the horse has bolted, is not good amateur practice. Having the horse bolt several hundred times during a QSO is not pleasant for others.

Feedback ALC systems dont belong in modern ham equipment. All Japanese transceivers have ALC overshoot issues. We need to get back to the transmitter gain or drive adjustments that set the drive power precisely with no overshoot. Its a nice dream that does not exist in modern ham transceiver. Most commercial and mil SSB equipment have a drive or TGA(transmitter gain adjustment) knob.

John

--- On Sat, 5/15/10, Vic K2VCO <[hidden email]> wrote:

> From: Vic K2VCO <[hidden email]>
> Subject: Re: [Elecraft] K3 - SPE Expert 1K-FA and ALC
> To: "David M. Elliott" <[hidden email]>
> Cc: [hidden email]
> Date: Saturday, May 15, 2010, 3:56 PM
> Any time the gain of the system
> changes, there's distortion. In SSB mode, I would expect
> it to occur when the ALC voltage changes, such as at the
> beginning of syllables, etc.
>
> On 5/15/2010 3:10 PM, David M. Elliott wrote:
> > In general, I would agree with You and Guy and Vic.
> >
> > However, Gianfranco of SPE (Expert) suggests running
> the exciter at full power. He
> > says there is no splatter and the proof of the pudding
> is in the eating. That seems to
> > be true. I can't see any splatter on the
> WaveNode and several on the air tests report
> > fine audio with no splatter.
> >
> > I repeat: There is something here we don't
> understand.
> >
> > Any comment, Gianfranco?
> --
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

W8JI

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by DAVID M. Elliott

>>However, Gianfranco of SPE (Expert) suggests running the
>>exciter at full power. He says there is no splatter and
>>the proof of the pudding is in the eating. >>That seems
>>to be true. I can't see any splatter on the WaveNode and
>>several on the air tests report fine audio with no
>>splatter.

>>I repeat: There is something here we don't understand.

We went through this ALC stuff just one month or so ago. The
problem with ALC is the ALC system response delay and the
propagation delay through the radio, especially narrow
filters. The leading edge of everything takes a hit until
the ALC level comes up. The time delay to interact with the
system is the problem. With a reasonable ALC hang time the
splatter is not too objectionable on a crowded band, but on
real quiet bands it can be disruptive to weak signals. It is
a very broad bandwidth short duration problem.

In my opinion it isn't the major problem we face with SSB
bandwidth and we may be over focusing a little on it. The
duration is so short the average power is very low, but it
is there. It would be very easy to miss on a spectrum
analyzer, as a matter of fact I would say it is nearly
impossible to catch. A selective level meter would be a far
better detector.

The real problem is the K3 has a unique ALC system that is
in front of the filtering, so leading edge delay isn't an
issue. Since the K3 has no leading edge transients, and
since anything after the radio (except a clamp or fast
attenuator) can not fix the transients, I don't see why
anyone would want to run external ALC with the K3.

Here is what Wayne said:

<<<<<<<<<<<<<<<<<<<<<<<
K3 external ALC setup is covered on page 27 of the owner's
manual.
Please read this page before attempting to use external ALC
with any
amplifier.

Executive summary:

1. DO NOT turn the K3's power all the way up and use
amplifier ALC to
maintain peak power at the output of your amplifier. This
WILL NOT work.

2. Instead, adjust the power level at the K3 to provide just
enough
drive to hit the peak power desired at the amp. You may want
to set
CONFIG:PWR SET to PER BAND so you don't have to adjust power
each time
you change bands. (This is also covered on page 27.)

3. External ALC is accommodated as a safety backup in the
event that
peak power suddenly increases, etc., due to a failure or
load change.
When properly applied, it will rarely be needed.

Technical details:

The K3 is designed to *not* depend on fast external ALC,
because that
absolutely, positively causes splatter. We studied lab work
from
several authors on this topic and decided to take a
different
approach: our fast ALC is all applied *ahead* of the 1st
I.F. crystal
filter (it's handled by DSP, at the AF and 2nd I.F. stages).
We do
apply slow, long-term ALC after the crystal filter, but this
can't
cause splatter because of the long time constant. External
ALC, if
used, is factored into this part of the equation.

Yes, the K3 is unique in this regard. It may be slightly
inconvenient,
but it will result in a cleaner signal.

73,
Wayne
N6KR

>>>>>>>>>>>>>>>>>>

73 Tom

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Guy, K2AV

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by Guy, K2AV

Hi Dave,

Thank you for the pictures. Worth thousand words, etc. And there IS
difference between the two. Can you detail the setup from end to end,
particularly your RX setup and K3 TX voice settings?

I'm not sure what your audio waveform is from exactly in A and B,
you'll need to tell us. But if that's human voice, it's a very
base-dominated voice spectrum, unlikely to generate obvious splatter.
The 0-400 or 0-500 band, whatever it is, is 18 db above the next
strongest band in your "modulation quickview", and so the lowest band
is completely controlling the power, not the attack of the silibants.
This would not be the measured waveform for a contest optimized voice,
with the treble accentuated for "punch", where splatter-producing
TX/amp setups show their true colors.

Set up for contest "punch". Do the comparison with the lower
frequencies severely reduced in the K3 TX equalization, and the
compression up around 20-30. Or get your wife to do the voice and
have her holler at the mike like it was the kids (only a few
assumptions there...). Turn OFF the averaging in the program and
leave the peak hold on. The duration and hence the average power of
silibants are quite less than the lower frequencies, and the
distortion products off silibants even less. It is the distortion's
instantaneous peak power that causes the most problem, not its peak
power times duration (average power).

The speech used for the test should be on a recording. Run the K3
barefoot off the recording, bypassing the amp, measure and make your
pictures, and then include the amp and repeat from the recording
without changing anything on the K3. This is probably a 25 watt A/B
and a 100 watt A/B. The receiving device should be run with FIXED
gain, NO RX AGC, any overdrive issues worked out in advance. Compare
those spectrums. But even this is still approximate, because the RX
device (unless it's a very good RX device like another K3 or K2) can
create the highest distortion which covers up any true differences.

The real test would be to run a very stable square rise and fall CW
dit with a pulse width of about 2 or 3 milliseconds with a repetition
rate of about one second, and repeating the test for longer pulse
widths. This requires a signal generator followed by a high power lab
linear amp instead of a K3 to drive the amp, but would isolate added
spectrum that occurs on predictable frequencies at predictable times
and can be precisely measured. The receiving device and presentation
would have to be certified for the general circumstances. I don't own
this stuff either, just get to drool on it during isolated
opportunities.

As to others listening for splatter, one WOULD think others could hear
it. However, back in the day of controversy over what rigs had and
didn't have key clicks, it was amazing how many people could NOT hear
or otherwise detect the bad clicks on a MEASURED dirty rig, for
whatever reason I really don't know. So I'm skeptical since I don't
see much difference in hearing splatter and hearing key clicks.

The problem I have, even if the SBE does manage to do amplification
relatively cleanly, is if someone else reads this thread later on
without any blowback on the claim, the readers extrapolate to other
amps and there it goes... So the SBE method is not going without
blowback. SBE may think they have created a marketing
differentiation, but for the time being they've crossed themselves off
my list on account of recommending smashmouth drive and ALC. What
else that I don't know about, yet?

73, Guy.

On Sat, May 15, 2010 at 6:32 PM, David M. Elliott
<[hidden email]> wrote:

>
>
> These two screen shots were taken using a WaveNode WN2. The exciter was a K3 and the amplifier was the Expert 1K FA. Both were SSB at 3.952 MHz. The conditions for both of these screen shots were the same except that the first one was using an exciter power of 25 watts and the second was using an exciter power of 100 watts. The amp was using ALC control in both cases.
>
> I don't see any signs of splatter in either case, do you?
>
> This test seems to support what the Expert folks are saying.
>
> 73 de W6BK
>
>
> On May 15, 2010, at 1:48 PM, Guy Olinger K2AV wrote:
>
>> Because if you are using something you can measure, like two tone, the
>> gains are already set and steady. To measure leading edge distortions
>> before an AGC loop or loops bite and settle takes some pretty
>> expensive lab equipment, both before and after the transmitter/amp.
>> What you got?
>>
>> It IS terrible advice.
>>
>> 73, Guy.
>>
>> On Sat, May 15, 2010 at 4:25 PM, David M. Elliott
>> <[hidden email]> wrote:
>>> If increased distortion is guaranteed, why doesn't it show on the spectrum scope?
>>>
>>> We are obviously missing something here.
>>>
>>> 73 de W6BK
>>>
>>>
>>> On May 15, 2010, at 11:03 AM, Vic K2VCO wrote:
>>>
>>>> Sorry, with all due respect this is HORRIBLE advice.
>>>>
>>>> I won't argue with those that say that the ALC should be connected for its protective
>>>> value. But it should not be depended on to control output level -- the exciter should be
>>>> adjusted to produce approximately the drive required for full output.
>>>>
>>>> The SPE Expert may have an exclusive design, but it is not exclusive enough to include a
>>>> time machine so that it can know how loud the operator is planning to talk, and it doesn't
>>>> control the delay inherent in the exciter's ALC circuitry.
>>>>
>>>> The result is guaranteed to be increased distortion.
>>>>
>>>> On 5/15/2010 4:25 AM, Björn Mohr wrote:
>>>>> 2010/4/22, LA8AW<[hidden email]>:
>>>>>
>>>>>
>>>>> Here is the statement from the developer of the SPE Expert 1K-FA - regarding
>>>>>> ALC, quoted from an early Expert Reflector:....
>>>>>>
>>>>>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>>>>>
>>>>>> We really suggest to always leave the transceiver's output power manual control to
>>>>>> its maximum level because the EXPERT, thanks to its exclusive design, will provide to
>>>>>> control that level as long as the required optimal value will be reached.
>>>>
>>>>
>>>> --
>>>> Vic, K2VCO
>>>> Fresno CA
>>>> http://www.qsl.net/k2vco/
>>>> ______________________________________________________________
>>>> 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
>>>
>>> ______________________________________________________________
>>> 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
>>>
>
>

DAVID M. Elliott

Re: K3 - SPE Expert 1K-FA and ALC

Thanks Guy for the well thought out response. Now we are getting somewhere.

The setup is a K3 using an Elecraft hand microphone feeding an Expert 1K FA solid state linear to a Windom antenna. The detector is a WaveNode WM2. The RF sensor module is between the Expert and the Antenna. The WaveNode is described on their web site (You can Google it,) and the manual is there too. The K3 is set up using ESSB with a width of 3.2. The tx equalizer is flat except for bands 7 and 8 which are set for -6db. The audio was my spoken voice so would be different from A to B. I have been told that I have a "radio voice" and should have been in broadcasting. I made a few radio and tv commercials for a company I worked for in the mid 1970s and to this day I have people come up to me and ask if I was on the radio in Cleveland. Somehow they remember the voice after decades. As you say, it is very base dominated.

The WaveNode is a really fun toy which I am just now figuring out how to use. What I look for to see splatter is the presence of colors other than green in the Modulation Quickview window. If I see that, I know there is splatter. If I don't, then I assume I am OK.

As you suggest, I will try this with the tx equalizer set up for narrow contest operation. I'll let you know what happens.

In any case, I am convinced that the K3 should be operated with the Expert with each band of the K3 set for only the power necessary to drive the Expert to its rated power. In my case, this is 15 watts plus or minus a few. It is interesting to note that I can drive the Expert to nearly full power with my QRP K2.

I'll report back on further tests. Thanks for all your good words.

73 de W6BK

On May 15, 2010, at 6:06 PM, Guy Olinger K2AV wrote:

> Hi Dave,
>
> Thank you for the pictures. Worth thousand words, etc. And there IS
> difference between the two. Can you detail the setup from end to end,
> particularly your RX setup and K3 TX voice settings?
>
> I'm not sure what your audio waveform is from exactly in A and B,
> you'll need to tell us. But if that's human voice, it's a very
> base-dominated voice spectrum, unlikely to generate obvious splatter.
> The 0-400 or 0-500 band, whatever it is, is 18 db above the next
> strongest band in your "modulation quickview", and so the lowest band
> is completely controlling the power, not the attack of the silibants.
> This would not be the measured waveform for a contest optimized voice,
> with the treble accentuated for "punch", where splatter-producing
> TX/amp setups show their true colors.
>
> Set up for contest "punch". Do the comparison with the lower
> frequencies severely reduced in the K3 TX equalization, and the
> compression up around 20-30. Or get your wife to do the voice and
> have her holler at the mike like it was the kids (only a few
> assumptions there...). Turn OFF the averaging in the program and
> leave the peak hold on. The duration and hence the average power of
> silibants are quite less than the lower frequencies, and the
> distortion products off silibants even less. It is the distortion's
> instantaneous peak power that causes the most problem, not its peak
> power times duration (average power).
>
> The speech used for the test should be on a recording. Run the K3
> barefoot off the recording, bypassing the amp, measure and make your
> pictures, and then include the amp and repeat from the recording
> without changing anything on the K3. This is probably a 25 watt A/B
> and a 100 watt A/B. The receiving device should be run with FIXED
> gain, NO RX AGC, any overdrive issues worked out in advance. Compare
> those spectrums. But even this is still approximate, because the RX
> device (unless it's a very good RX device like another K3 or K2) can
> create the highest distortion which covers up any true differences.
>
> The real test would be to run a very stable square rise and fall CW
> dit with a pulse width of about 2 or 3 milliseconds with a repetition
> rate of about one second, and repeating the test for longer pulse
> widths. This requires a signal generator followed by a high power lab
> linear amp instead of a K3 to drive the amp, but would isolate added
> spectrum that occurs on predictable frequencies at predictable times
> and can be precisely measured. The receiving device and presentation
> would have to be certified for the general circumstances. I don't own
> this stuff either, just get to drool on it during isolated
> opportunities.
>
> As to others listening for splatter, one WOULD think others could hear
> it. However, back in the day of controversy over what rigs had and
> didn't have key clicks, it was amazing how many people could NOT hear
> or otherwise detect the bad clicks on a MEASURED dirty rig, for
> whatever reason I really don't know. So I'm skeptical since I don't
> see much difference in hearing splatter and hearing key clicks.
>
> The problem I have, even if the SBE does manage to do amplification
> relatively cleanly, is if someone else reads this thread later on
> without any blowback on the claim, the readers extrapolate to other
> amps and there it goes... So the SBE method is not going without
> blowback. SBE may think they have created a marketing
> differentiation, but for the time being they've crossed themselves off
> my list on account of recommending smashmouth drive and ALC. What
> else that I don't know about, yet?
>
> 73, Guy.
>
> On Sat, May 15, 2010 at 6:32 PM, David M. Elliott
> <[hidden email]> wrote:
>>
>>
>> These two screen shots were taken using a WaveNode WN2. The exciter was a K3 and the amplifier was the Expert 1K FA. Both were SSB at 3.952 MHz. The conditions for both of these screen shots were the same except that the first one was using an exciter power of 25 watts and the second was using an exciter power of 100 watts. The amp was using ALC control in both cases.
>>
>> I don't see any signs of splatter in either case, do you?
>>
>> This test seems to support what the Expert folks are saying.
>>
>> 73 de W6BK
>>
>>
>> On May 15, 2010, at 1:48 PM, Guy Olinger K2AV wrote:
>>
>>> Because if you are using something you can measure, like two tone, the
>>> gains are already set and steady. To measure leading edge distortions
>>> before an AGC loop or loops bite and settle takes some pretty
>>> expensive lab equipment, both before and after the transmitter/amp.
>>> What you got?
>>>
>>> It IS terrible advice.
>>>
>>> 73, Guy.
>>>
>>> On Sat, May 15, 2010 at 4:25 PM, David M. Elliott
>>> <[hidden email]> wrote:
>>>> If increased distortion is guaranteed, why doesn't it show on the spectrum scope?
>>>>
>>>> We are obviously missing something here.
>>>>
>>>> 73 de W6BK
>>>>
>>>>
>>>> On May 15, 2010, at 11:03 AM, Vic K2VCO wrote:
>>>>
>>>>> Sorry, with all due respect this is HORRIBLE advice.
>>>>>
>>>>> I won't argue with those that say that the ALC should be connected for its protective
>>>>> value. But it should not be depended on to control output level -- the exciter should be
>>>>> adjusted to produce approximately the drive required for full output.
>>>>>
>>>>> The SPE Expert may have an exclusive design, but it is not exclusive enough to include a
>>>>> time machine so that it can know how loud the operator is planning to talk, and it doesn't
>>>>> control the delay inherent in the exciter's ALC circuitry.
>>>>>
>>>>> The result is guaranteed to be increased distortion.
>>>>>
>>>>> On 5/15/2010 4:25 AM, Björn Mohr wrote:
>>>>>> 2010/4/22, LA8AW<[hidden email]>:
>>>>>>
>>>>>>
>>>>>> Here is the statement from the developer of the SPE Expert 1K-FA - regarding
>>>>>>> ALC, quoted from an early Expert Reflector:....
>>>>>>>
>>>>>>> I hope this will clarify the SPE Expert vs K3 - and ALC !!
>>>>>>>
>>>>>>> We really suggest to always leave the transceiver's output power manual control to
>>>>>>> its maximum level because the EXPERT, thanks to its exclusive design, will provide to
>>>>>>> control that level as long as the required optimal value will be reached.
>>>>>
>>>>>
>>>>> --
>>>>> Vic, K2VCO
>>>>> Fresno CA
>>>>> http://www.qsl.net/k2vco/
>>>>> ______________________________________________________________
>>>>> 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
>>>>
>>>> ______________________________________________________________
>>>> 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
>>>>
>>
>>

W8JI

Re: K3 - SPE Expert 1K-FA and ALC

David,

Bandwidth might not be a good argument. I'm not convinced
ALC transients are a major universal problem with SSB
signals when they are compared to other reasons for
bandwidth problems. This isn't the appropriate forum for
that discussion.

I have looked at ALC overshoot because of my connection with
amplifier designs and failures in semiconductors and other
sensitive components caused by ALC problems, and the pulse
duration is very short. That short pulse repeats only after
the ALC has discharged significantly, so the transmitter's
gain is high.

The problem is a great deal like automatic bias, where the
leading edge always causes some distortion as the circuitry
changes states. The deeper the bias, the more time it takes
to remove it and the stronger the unwanted off-channel
energy. ALC is a little worse because the control signal is
sampled after some delay and has to wrap back around to the
start. This means no matter what they do in the amplifier
the cannot cure the leading edge problem. The one exception
would be if they held the ALC voltage high and then pulled
it down to a level that allowed proper drive. They may be
doing that, but an indicator would be a slow power rise on
the leading edges. It is a mirror of normal ALC.

As for bandwidth measurements, I'm not convinced the
WaveNode is good at transient analysis. With FFT analysis,
the window where waveform is sampled has to be present at
the same time as the transient, and the processing cannot
average the power. It has to calculate to provide bandwidth
information of the very short duration peaks. The problem is
much like the reason a conventional spectrum analyzer will
miss ALC problems in all but a few really severe cases. If
it isn't sampling the transient frequency when it is there,
the extra bandwidth doesn't show.

I'm not convinced at all, because the overshoot is so short,
it is the major problem we hear on the air....or even a
significant one. I'm not convinced, and actually think it
unlikely, the WaveNode could measure such a short burst.

All that aside, because it is a big discussion, we are left
with the fact Elecraft has clearly warned to NOT do 100%
power control with an external ALC source. That warning is
100% understandable based on the unique way the K3 ALC
works. It is absolute common sense the K3 ALC should not be
replaced with a traditional external ALC for primary power
level control. Even without Wayne's warning, I would not do
it now that I understand how the K3 ALC works.

To prevent splatter, the K3's internal pre-filter ALC must
have primary control of power limits. The amplifier should
only provide a fail-safe control that pulls back or kills
the exciter drive if limits are reached.

By the way, I'm testing new PA module designs with an IC706.
It has terrible ALC overshoot. It has "100-watt plus"
transients when I have it set at 20 watts to drive the PA
modules. The K3 does not. Fortunately the MRF-150's are able
to handle the 600% overdrive bursts from the IC706 without
failure. I keep a couple ICOM's around just for that reason.

I cannot test for PA module survival with a bad ALC system
in the exciter using the K3, unless I ran the K3 power on
full and used an external ALC detector system. Then I could
make the K3 emulate the IC-706. Why would people not testing
things want to do that????

73 Tom

______________________________________________________________
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
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Guy, K2AV

Re: K3 - SPE Expert 1K-FA and ALC

In reply to this post by Guy, K2AV

Hi Dave,

I'm not sure that the embedded picture I received from you would be passed
by the reflector, so I'm just quoting your text below.

The graphics show that peak distortion in the adjacent channel was only down
25 db from in-channel max power. This even though your trebled up voice is
still fairly bass controlled.

Which means that if you were up or down from this signal at 20 over on
channel, you would be hearing S8 or S9 splatter from it. Sounds familiar,
doesn't it.

The 1500 watt power spike is particularly frightening, especially if it
comes out of my wallet. Might want to pass your results on to the
manufacturer as a customer and request they pull that recommendation from
their publications and web page. Make sure they understand it's getting them
a lot of bad press and is NOT panning out.

About as graphic an underscore to Wayne's warning as one can get. (Sorry,
couldn't resist....)

73, Guy

>>

Hello Guy,

Well, you sure called it. This screen shot is taken under the same
conditions as the previous ones except that the tx equalizer was set to try
and simulate a Heil HC4. The tx equalizer settings were: 1 - 0db, 2 - 0db,
3 - 0db, 4 - 0db, 5 - +2db, 6 - + 4db, 7 - + 10db, and 8 - +10db. Two
things I noticed right away: First, the peak power is nearly 1500 watts! I
sure am glad I still have finals in the Expert. Second, there is definite
splatter as evidenced by the light and dark blue on the Modulation quickview
window.

One can say a lot of things about these tests but one thing comes through
loud and clear to me:

ALC should not be used to control the K3 set to 100 watts with the Expert 1K
FA. Rather the power should be set on each band to just what the Expert
needs to reach full power.

To do otherwise may cause splatter and might result in final failure. How
long can the Expert finals take this kind of abuse?

73 de W6BK
______________________________________________________________
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
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DAVID M. Elliott

Re: K3 - SPE Expert 1K-FA and ALC

Hi Guy,

Apparently the reflector does not pass emails with large attachments. I think it is pretty graphic and I would like others to see it if I can figure out how. I'll call SteppIR tomorrow and discuss it with them. I support your recommendation
that they take that recommended method of operation out of their manual. I will forward that email to Gianfranco at SPE (Expert).

Thanks for all your help.

73 de W6BK

On May 16, 2010, at 1:20 PM, Guy Olinger K2AV wrote:

> Hi Dave,
>
> I'm not sure that the embedded picture I received from you would be passed by the reflector, so I'm just quoting your text below.
>
> The graphics show that peak distortion in the adjacent channel was only down 25 db from in-channel max power. This even though your trebled up voice is still fairly bass controlled.
>
> Which means that if you were up or down from this signal at 20 over on channel, you would be hearing S8 or S9 splatter from it. Sounds familiar, doesn't it.
>
> The 1500 watt power spike is particularly frightening, especially if it comes out of my wallet. Might want to pass your results on to the manufacturer as a customer and request they pull that recommendation from their publications and web page. Make sure they understand it's getting them a lot of bad press and is NOT panning out.
>
> About as graphic an underscore to Wayne's warning as one can get. (Sorry, couldn't resist....)
>
> 73, Guy
>
> >>
>
> Hello Guy,
>
> Well, you sure called it. This screen shot is taken under the same conditions as the previous ones except that the tx equalizer was set to try and simulate a Heil HC4. The tx equalizer settings were: 1 - 0db, 2 - 0db, 3 - 0db, 4 - 0db, 5 - +2db, 6 - + 4db, 7 - + 10db, and 8 - +10db. Two things I noticed right away: First, the peak power is nearly 1500 watts! I sure am glad I still have finals in the Expert. Second, there is definite splatter as evidenced by the light and dark blue on the Modulation quickview window.
>
> One can say a lot of things about these tests but one thing comes through loud and clear to me:
>
> ALC should not be used to control the K3 set to 100 watts with the Expert 1K FA. Rather the power should be set on each band to just what the Expert needs to reach full power.
>
> To do otherwise may cause splatter and might result in final failure. How long can the Expert finals take this kind of abuse?
>
> 73 de W6BK

Guy, K2AV

Re: K3 - SPE Expert 1K-FA and ALC

The usual way is to put it up on a web page somewhere, and put the
link in the email.

73, Guy

On Sun, May 16, 2010 at 5:07 PM, David M. Elliott
<[hidden email]> wrote:

> Hi Guy,
> Apparently the reflector does not pass emails with large attachments. I
> think it is pretty graphic and I would like others to see it if I can figure
> out how. I'll call SteppIR tomorrow and discuss it with them. I support
> your recommendation
> that they take that recommended method of operation out of their manual. I
> will forward that email to Gianfranco at SPE (Expert).
> Thanks for all your help.
> 73 de W6BK
>
> On May 16, 2010, at 1:20 PM, Guy Olinger K2AV wrote:
>
> Hi Dave,
>
> I'm not sure that the embedded picture I received from you would be passed
> by the reflector, so I'm just quoting your text below.
>
> The graphics show that peak distortion in the adjacent channel was only down
> 25 db from in-channel max power. This even though your trebled up voice is
> still fairly bass controlled.
>
> Which means that if you were up or down from this signal at 20 over on
> channel, you would be hearing S8 or S9 splatter from it. Sounds familiar,
> doesn't it.
>
> The 1500 watt power spike is particularly frightening, especially if it
> comes out of my wallet. Might want to pass your results on to the
> manufacturer as a customer and request they pull that recommendation from
> their publications and web page. Make sure they understand it's getting them
> a lot of bad press and is NOT panning out.
>
> About as graphic an underscore to Wayne's warning as one can get. (Sorry,
> couldn't resist....)
>
> 73, Guy
>
>>>
>
> Hello Guy,
> Well, you sure called it. This screen shot is taken under the same
> conditions as the previous ones except that the tx equalizer was set to try
> and simulate a Heil HC4. The tx equalizer settings were: 1 - 0db, 2 - 0db,
> 3 - 0db, 4 - 0db, 5 - +2db, 6 - + 4db, 7 - + 10db, and 8 - +10db. Two
> things I noticed right away: First, the peak power is nearly 1500 watts! I
> sure am glad I still have finals in the Expert. Second, there is definite
> splatter as evidenced by the light and dark blue on the Modulation quickview
> window.
> One can say a lot of things about these tests but one thing comes through
> loud and clear to me:
> ALC should not be used to control the K3 set to 100 watts with the Expert 1K
> FA. Rather the power should be set on each band to just what the Expert
> needs to reach full power.
> To do otherwise may cause splatter and might result in final failure. How
> long can the Expert finals take this kind of abuse?
> 73 de W6BK
>
>