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K3--Too much ALC creates energy on opposite sideband?

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Nate Bargmann

K3--Too much ALC creates energy on opposite sideband?

I received a note this morning advising that I should check my ALC as he
is seeing some energy on USB when I check into a 75m voice net on LSB.
I am using an MC-50 microphone and am running the mic gain at 35 and the
compression at 11. My thinking was that generating opposite sideband
energy would be quite difficult with the K3's DSP. Am I wrong?

I'll try working with him some morning and back down the mic gain a bit
and see what that does for him.

73, Nate, N0NB

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Web: https://www.n0nb.us
Projects: https://github.com/N0NB
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Don Wilhelm

Re: K3--Too much ALC creates energy on opposite sideband?

Nate,

One thing is that you have a LOT of compression. That may be causing his
receiving to show excess energy, maybe even lapping over into the
opposite sideband.

First set the compression to zero, then either connect a dummy load or
use TX TEST and adjust the mic gain for 5 to 7 bars on the ALC meter -
the 7 bars should be seen only on peaks.

After that, you can increase the compression, but I would limit it to 6
dB for normal operation.

73,
Don W3FPR

On 8/28/2019 12:40 PM, Nate Bargmann wrote:
> I received a note this morning advising that I should check my ALC as he
> is seeing some energy on USB when I check into a 75m voice net on LSB.
> I am using an MC-50 microphone and am running the mic gain at 35 and the
> compression at 11. My thinking was that generating opposite sideband
> energy would be quite difficult with the K3's DSP. Am I wrong?
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k6dgw

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

Nate:

You should run your MIC gain such that you see 4 bars of ALC with the
5th just flickering occasionally on voice peaks. Make this adjustment
with compression at zero. Then, adjust the compression as desired. I
generally set it so that voice peaks show 10 dB compression. The first
4 bars on the ALC display are in fact just a VU meter. ALC action
begins at the 5th bar. Elecraft transceivers set the power out with a
closed feedback loop [PWR setting], not the MIC gain.

Driving the ALC too hard will create IMD which, among other things, will
show up as energy on the opposite sideband. It all happens in the RF
chain after the DSP has generated the SSB.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 8/28/2019 9:40 AM, Nate Bargmann wrote:

> I received a note this morning advising that I should check my ALC as he
> is seeing some energy on USB when I check into a 75m voice net on LSB.
> I am using an MC-50 microphone and am running the mic gain at 35 and the
> compression at 11. My thinking was that generating opposite sideband
> energy would be quite difficult with the K3's DSP. Am I wrong?
>
> I'll try working with him some morning and back down the mic gain a bit
> and see what that does for him.
>
> 73, Nate, N0NB
>

NK7Z

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

I have to say it... Maybe he things you have an Icom? :)

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Technical Specialist
ARRL Volunteer Examiner
ARRL Asst. Director, NW Division, Technical Resources

On 8/28/19 9:40 AM, Nate Bargmann wrote:

Wes Stewart-2

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

Although the manual doesn't say so, according to an ARRL review, the K3S is
specified to have undesired sideband suppression of >50 dB. ARRL claims an
optimistic >70 dB.

So if you are extremely strong at the other guy's place, he might easily hear an
opposite sideband, even though your radio is operating correctly. Ask him what
the ratio is.

Wes N7WS

On 8/28/2019 9:40 AM, Nate Bargmann wrote:

David Gilbert

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

I don't know about others, but when I got my K3 I did a lot of testing
into a dummy load using my previous rig with a short piece of wire for
an antenna to monitor my K3 audio. I found anything above about 25 for
mic gain was objectionable, at least to me.

73,
Dave AB7E

On 8/28/2019 9:40 AM, Nate Bargmann wrote:

donovanf

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by k6dgw

Hi Fred,

The ALC level you recommended is the recommended level for digital modes such as FT8 where no ALC is the standard practice.
Elecraft's recommended for the K3 or K3S ALC level when operating in voice modes is 5-7 bars.

The exact quote from page 30 of the latest K3S manual
https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S%20Owner's%20man%20A1.pdf

Optionally select TX TEST mode (pg. 13) or set power to zero. This will not affect your CMP/ALC bar graph readings.

Set CMP to 0

Hold METER to select CMP/ALC metering

While speaking into the microphone in a normal voice, adjust MIC for a peak ALC meter indication of about 5-7 bars (see below).

Adjust CMP for the desired speech compression level while speaking.The CMP scale shows approximate compression level.

73
Frank
W3LPL

----- Original Message -----

From: "Fred Jensen" <[hidden email]>
To: [hidden email]
Sent: Wednesday, August 28, 2019 5:19:58 PM
Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?

Nate:

You should run your MIC gain such that you see 4 bars of ALC with the
5th just flickering occasionally on voice peaks. Make this adjustment
with compression at zero. Then, adjust the compression as desired. I
generally set it so that voice peaks show 10 dB compression. The first
4 bars on the ALC display are in fact just a VU meter. ALC action
begins at the 5th bar. Elecraft transceivers set the power out with a
closed feedback loop [PWR setting], not the MIC gain.

Driving the ALC too hard will create IMD which, among other things, will
show up as energy on the opposite sideband. It all happens in the RF
chain after the DSP has generated the SSB.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 8/28/2019 9:40 AM, Nate Bargmann wrote:

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Jim Brown-10

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Wes Stewart-2

Numerical readouts for Mic Gain and Comp are pretty meaningless, because
the output of good mics varies widely from one model to another, how
close the mic is to the mouth, how loud we talk. The right way to set
(and understand) these controls is to look at indicated ALC and CMP on
the bar graph display while transmitting. Both adjustments should be
made AFTER setting TXEQ. I have long advocated 10 dB of indicated CMP on
voice peaks.

It is well known that IMD in the K3 and K3S increases when operating
from low DC supply voltage. It also increases when the output stage is
operating near its limit, and when the antenna is not well matched to
the output stage. If the 100W amp is present, it does not engage until
output power is set above about 15W, so IMD is also higher when running
12-15W. The increased IMD of the 100W state can be clearly seen in this
set of data. DC voltage was in the range of 12.5V for these
measurements. http://k9yc.com/P3_Spectrum_Measurements.pdf

Pink noise is widely used by audio professionals because its spectral
distribution more closely corresponds to music and speech than does
white noise. For that reason, pink noise is the best test signal for the
evaluation of speech processing systems (like CMP and peak limiting).

73, Jim K9YC

8/28/2019 10:45 AM, Wes wrote:

> Although the manual doesn't say so, according to an ARRL review, the K3S
> is specified to have undesired sideband suppression of >50 dB. ARRL
> claims an optimistic >70 dB.
>
> So if you are extremely strong at the other guy's place, he might easily
> hear an opposite sideband, even though your radio is operating
> correctly. Ask him what the ratio is.
>
> Wes N7WS
>
> On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>> I received a note this morning advising that I should check my ALC as he
>> is seeing some energy on USB when I check into a 75m voice net on LSB.
>> I am using an MC-50 microphone and am running the mic gain at 35 and the
>> compression at 11. My thinking was that generating opposite sideband
>> energy would be quite difficult with the K3's DSP. Am I wrong?
>>
>> I'll try working with him some morning and back down the mic gain a bit
>> and see what that does for him.

Barry LaZar

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Wes Stewart-2

Wes,
You make a very good point. The unwanted sideband will not be 0;
there will be some "residue" that can be heard if the signal is strong
enough. And, a lot has to do with the measurement method at the
receiver.

Years ago, I was running DSBSC using a Globe DSB-100. I was told
that my carrier was way down but my unwanted sideband was only 20 db
down. That was interesting as I made no effort to suppress my unwanted
sideband. The problem was the method that was used to make the
measurements and the strength of my signal. So, determining the ratio of
the two sidebands might be difficult, but it may be the correct
approach, However, it will require being able to "see" both sidebands on
an equal basis.

73,
Barry
K3NDM

------ Original Message ------
From: "Wes" <[hidden email]>
To: [hidden email]
Sent: 8/28/2019 1:45:11 PM
Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite
sideband?

>Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB.
>
>So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is.
>
>Wes N7WS
>
>On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>>I received a note this morning advising that I should check my ALC as he
>>is seeing some energy on USB when I check into a 75m voice net on LSB.
>>I am using an MC-50 microphone and am running the mic gain at 35 and the
>>compression at 11. My thinking was that generating opposite sideband
>>energy would be quite difficult with the K3's DSP. Am I wrong?
>>
>>I'll try working with him some morning and back down the mic gain a bit
>>and see what that does for him.
>>
>>73, Nate, N0NB
>>
>
>______________________________________________________________
>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]

Wes Stewart-2

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Jim Brown-10

What has any of that to do with opposite sideband rejection?

Wes N7WS

BTW, The HPA kicks in at 12 W.

On 8/28/2019 12:55 PM, Jim Brown wrote:

> Numerical readouts for Mic Gain and Comp are pretty meaningless, because the
> output of good mics varies widely from one model to another, how close the mic
> is to the mouth, how loud we talk. The right way to set (and understand) these
> controls is to look at indicated ALC and CMP on the bar graph display while
> transmitting. Both adjustments should be made AFTER setting TXEQ. I have long
> advocated 10 dB of indicated CMP on voice peaks.
>
> It is well known that IMD in the K3 and K3S increases when operating from low
> DC supply voltage. It also increases when the output stage is operating near
> its limit, and when the antenna is not well matched to the output stage. If
> the 100W amp is present, it does not engage until output power is set above
> about 15W, so IMD is also higher when running 12-15W. The increased IMD of the
> 100W state can be clearly seen in this set of data. DC voltage was in the
> range of 12.5V for these measurements.
> http://k9yc.com/P3_Spectrum_Measurements.pdf
>
> Pink noise is widely used by audio professionals because its spectral
> distribution more closely corresponds to music and speech than does white
> noise. For that reason, pink noise is the best test signal for the evaluation
> of speech processing systems (like CMP and peak limiting).
>
> 73, Jim K9YC
>
> 8/28/2019 10:45 AM, Wes wrote:
>> Although the manual doesn't say so, according to an ARRL review, the K3S is
>> specified to have undesired sideband suppression of >50 dB. ARRL claims an
>> optimistic >70 dB.
>>
>> So if you are extremely strong at the other guy's place, he might easily hear
>> an opposite sideband, even though your radio is operating correctly. Ask him
>> what the ratio is.
>>
>> Wes N7WS
>>
>> On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>>> I received a note this morning advising that I should check my ALC as he
>>> is seeing some energy on USB when I check into a 75m voice net on LSB.
>>> I am using an MC-50 microphone and am running the mic gain at 35 and the
>>> compression at 11. My thinking was that generating opposite sideband
>>> energy would be quite difficult with the K3's DSP. Am I wrong?
>>>
>>> I'll try working with him some morning and back down the mic gain a bit
>>> and see what that does for him.

Michael Walker

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Barry LaZar

I agree with Jim and what I tell hams every day since I seem to talk to a
bunch of them on the phone.

Do NOT use the settings other tell you, set up the radio by using the
Meters in the radio, in this case the ALC. That is the reason it is on the
radio.

The more ALC you have, the more the radio is already shutting down down
your audio gain and hence the reason it is called Automatic Limiting
Control.

I am not a big fan of compression and in today's world there really is no
requirement to have it on. Ask anyone who has been DXPedition end of a
DXPedition and they will tell you to turn it off as it is actually harder
to understand you.

It 'might' look like you have more power out, but it is not really in a
good way.

This is also a good time to review page 28 on "Voice Modes" and follow the
steps the way the Engineers who designed this want you to set up your
radio. They are pretty smart people. :)

I hope that helps, Mike va3mw

On Wed, Aug 28, 2019 at 4:33 PM Barry <[hidden email]> wrote:

> Wes,
> You make a very good point. The unwanted sideband will not be 0;
> there will be some "residue" that can be heard if the signal is strong
> enough. And, a lot has to do with the measurement method at the
> receiver.
>
> Years ago, I was running DSBSC using a Globe DSB-100. I was told
> that my carrier was way down but my unwanted sideband was only 20 db
> down. That was interesting as I made no effort to suppress my unwanted
> sideband. The problem was the method that was used to make the
> measurements and the strength of my signal. So, determining the ratio of
> the two sidebands might be difficult, but it may be the correct
> approach, However, it will require being able to "see" both sidebands on
> an equal basis.
>
> 73,
> Barry
> K3NDM
>
> ------ Original Message ------
> From: "Wes" <[hidden email]>
> To: [hidden email]
> Sent: 8/28/2019 1:45:11 PM
> Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite
> sideband?
>
> >Although the manual doesn't say so, according to an ARRL review, the K3S
> is specified to have undesired sideband suppression of >50 dB. ARRL claims
> an optimistic >70 dB.
> >
> >So if you are extremely strong at the other guy's place, he might easily
> hear an opposite sideband, even though your radio is operating correctly.
> Ask him what the ratio is.
> >
> >Wes N7WS
> >
> >On 8/28/2019 9:40 AM, Nate Bargmann wrote:
> >>I received a note this morning advising that I should check my ALC as he
> >>is seeing some energy on USB when I check into a 75m voice net on LSB.
> >>I am using an MC-50 microphone and am running the mic gain at 35 and the
> >>compression at 11. My thinking was that generating opposite sideband
> >>energy would be quite difficult with the K3's DSP. Am I wrong?
> >>
> >>I'll try working with him some morning and back down the mic gain a bit
> >>and see what that does for him.
> >>
> >>73, Nate, N0NB
> >>
> >
> >______________________________________________________________
> >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]
>
> ______________________________________________________________
> 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]
>

Wes Stewart-2

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Barry LaZar

Barry,

With my SDR-IQ looking at the K3S i-f output I can see the other guy's
signature. I suppose a P3 does the same. It's pretty amazing to see some of
the lousy signals when we have such improved technology.

Wes

On 8/28/2019 1:30 PM, Barry wrote:

> Wes,
> You make a very good point. The unwanted sideband will not be 0; there
> will be some "residue" that can be heard if the signal is strong enough. And,
> a lot has to do with the measurement method at the receiver.
>
> Years ago, I was running DSBSC using a Globe DSB-100. I was told that my
> carrier was way down but my unwanted sideband was only 20 db down. That was
> interesting as I made no effort to suppress my unwanted sideband. The problem
> was the method that was used to make the measurements and the strength of my
> signal. So, determining the ratio of the two sidebands might be difficult, but
> it may be the correct approach, However, it will require being able to "see"
> both sidebands on an equal basis.
>
> 73,
> Barry
> K3NDM
>
> ------ Original Message ------
> From: "Wes" <[hidden email]>
> To: [hidden email]
> Sent: 8/28/2019 1:45:11 PM
> Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
>
>> Although the manual doesn't say so, according to an ARRL review, the K3S is
>> specified to have undesired sideband suppression of >50 dB. ARRL claims an
>> optimistic >70 dB.
>>
>> So if you are extremely strong at the other guy's place, he might easily hear
>> an opposite sideband, even though your radio is operating correctly. Ask him
>> what the ratio is.
>>
>> Wes N7WS
>>
>> On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>>> I received a note this morning advising that I should check my ALC as he
>>> is seeing some energy on USB when I check into a 75m voice net on LSB.
>>> I am using an MC-50 microphone and am running the mic gain at 35 and the
>>> compression at 11. My thinking was that generating opposite sideband
>>> energy would be quite difficult with the K3's DSP. Am I wrong?
>>>
>>> I'll try working with him some morning and back down the mic gain a bit
>>> and see what that does for him.
>>>
>>> 73, Nate, N0NB
>>>
>>
>> ______________________________________________________________
>> 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]
>
>

Jim Brown-10

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Michael Walker

On 8/28/2019 1:46 PM, Michael Walker wrote:
> I am not a big fan of compression and in today's world there really is no
> requirement to have it on. Ask anyone who has been DXPedition end of a
> DXPedition and they will tell you to turn it off as it is actually harder
> to understand you.

This is NOT true if compression is well adjusted -- 10 dB of well
adjusted compression increases talk power by 10 dB, and setting TXEQ to
remove speech content below 400 Hz helps by another 3 dB. It is the
abuse of compression that reduces intelligibility. Compression has been
universally used in all broadcasting modes for at least 60 years, and
for at least 40 years, for gain reductions of 30 dB or more! The joke
among FM broadcast engineers in the '70s was "If the meter in the
modulation monitor moves, the program director will say we're not loud
enough!"

73, Jim K9YC

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k6dgw

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by donovanf

Yes, I know what the manual says. However the IMD on my K3 goes up when
I set the mic gain to flicker bar 7 on voice peaks so I run it with
almost no ALC. I also set the TX EQ using the "K9YC Method," and
regularly get unsolicited "great audio" comments so I'm a fairly happy ham.

I'm not on SSB often, but when I do get on such as NAQP SSB, I'm always
a bit surprised at how many signals have all the sideband energy crammed
right up against the suppressed carrier. Not too many fill up their
BW. For those of us with compromised hearing, it makes copy difficult
... one of the several reasons I don't get on phone very often. All
that low frequency energy contributes almost nothing to intelligibility.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 8/28/2019 11:05 AM, [hidden email] wrote:

> Hi Fred,
>
> The ALC level you recommended is the recommended level for digital
> modes such as FT8 where *no ALC* is the standard practice.
> Elecraft's recommended for the K3 or K3S ALC level when operating in
> voice modes is *5-7 bars.*
>
> The exact quote from page 30 of the latest K3S manual
> https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S%20Owner's%20man%20A1.pdf
>
> Optionally select TX TEST mode (pg. 13) or set power to zero. This
> will not affect your CMP/ALC bar graph readings.
>
> Set CMP to 0
>
> Hold METER to select CMP/ALC metering
>
> While speaking into the microphone in a normal voice, adjust MIC for a
> peak ALC meter indication of about *5-7 bars* (see below).
>
> Adjust CMP for the desired speech compression level while speaking.The
> CMP scale shows approximate compression level.
>
> 73
> Frank
> W3LPL
>

Jim Brown-10

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Wes Stewart-2

On 8/28/2019 1:50 PM, Wes wrote:
> With my SDR-IQ looking at the K3S i-f output I can see the other guy's
> signature. I suppose a P3 does the same. It's pretty amazing to see
> some of the lousy signals when we have such improved technology.

Yes. I regularly see signals from SSB ragchewers with splatter in the
suppressed sideband only 10-15 dB below signal in the intentional
sideband. The data in the link I posted was with a P3 on my second K3,
with the K3 being measured into a dummy load.

I've alerted guys on 6M about this, suggesting they turn down drive to
their amplifier, and they said they didn't have an amplifier. When I
asked what rig, it was one of the low-cost do-everything rigs from one
of the big JA mfrs. When I posted this at the time, W4TV described the
mechanism (I think I remember that it was a shortcominBefore Elecraft
rigs took over Field Day, These cheap rigs (and even some much more
expensive ones) have long been considered the scourge of Field Day.

73, Jim K9YC
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Wes Stewart-2

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Jim Brown-10

It seems like often Jim and I disagree on things, but this time I'm in total
agreement with him.

About a year after my speech processor paper was published in Ham Radio Magazine
(http://k6mhe.com/n7ws/S_PROC.pdf) I worked a guy in the PNW, on ten meters. He
was running a homebrew 2 watt radio and using a copy of my processor. He was
delighted with it and the fact that we were talking. Frankly, it was the first
time I'd heard one from the other end. So he wanted to experiment. He was
about S2 but perfectly Q5. When he turned the processor off he was gone. Not a
peep. It was amazing. Frankly, I was impressed. I knew the theory but to see
it in action was eyeopening.

Wes N7WS

On 8/28/2019 2:18 PM, Jim Brown wrote:

> On 8/28/2019 1:46 PM, Michael Walker wrote:
>> I am not a big fan of compression and in today's world there really is no
>> requirement to have it on. Ask anyone who has been DXPedition end of a
>> DXPedition and they will tell you to turn it off as it is actually harder
>> to understand you.
>
> This is NOT true if compression is well adjusted -- 10 dB of well adjusted
> compression increases talk power by 10 dB, and setting TXEQ to remove speech
> content below 400 Hz helps by another 3 dB. It is the abuse of compression
> that reduces intelligibility. Compression has been universally used in all
> broadcasting modes for at least 60 years, and for at least 40 years, for gain
> reductions of 30 dB or more! The joke among FM broadcast engineers in the '70s
> was "If the meter in the modulation monitor moves, the program director will
> say we're not loud enough!"
>
> 73, Jim K9YC

ANDY DURBIN

K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

"The more ALC you have, the more the radio is already shutting down down your audio gain and hence the reason it is called Automatic Limiting Control."

Can you please cite any modern rig, preferably with reference to the schematics, for which ALC is applied to the audio signal? For the rigs I have studied ALC gain is applied somewhere in the Transmit IF, long after the modulation is applied.

Can you please provide any reference that defines ALC as Automatic Limiting Control?

73,
Andy, k3wyc

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Nate Bargmann

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Nate Bargmann

I think I better take a mea culpa on this one. One reply in a private
email asked if I was using and amp and whether I was driving it too
hard. Well, some mornings this week I have depending on static levels
and I operated the KS QSO Party this past weekend and ran 100W. I
normally run the amp (ALS-600) with the power setting at 70W.

This is probably just a, "D'oh!" moment. Yes, the K3 was still set for
100W.

Incidentally, My COMP runs about 2-3 bars on voice peaks and the ALC
meter is in the 5-7 bars range on peaks as well.

It's a PEBCAK3 issue. ;-)

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Web: https://www.n0nb.us
Projects: https://github.com/N0NB
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Michael Walker

Re: K3--Too much ALC creates energy on opposite sideband?

Hi Fred (Skip)

Sadly, many of those are splattering so wide that you can hear them on the
opposite sideband. Unfortunately, a report of great audio does not mean
great IMD performance.

Don't take this the wrong way, I am not saying you have bad IMD it just
that you can't relate the 2 has being an indicator.

With a good radio and a good waterfall you can see it plain as day. There
are a few locals (aka here in ve3 land) that I 'watch' routinely with their
top end Yaesu's (5000's) and they sound awesome, but they have the absolute
worst splatter you have ever seen. One guy on 80M was absolutely
understandable when I listened to him on USB.

Nate, glad you got it figured out. I'm sure we have all been there (me
included).

73 all, Mike va3mw

On Wed, Aug 28, 2019 at 9:43 PM Nate Bargmann <[hidden email]> wrote:

> I think I better take a mea culpa on this one. One reply in a private
> email asked if I was using and amp and whether I was driving it too
> hard. Well, some mornings this week I have depending on static levels
> and I operated the KS QSO Party this past weekend and ran 100W. I
> normally run the amp (ALS-600) with the power setting at 70W.
>
> This is probably just a, "D'oh!" moment. Yes, the K3 was still set for
> 100W.
>
> Incidentally, My COMP runs about 2-3 bars on voice peaks and the ALC
> meter is in the 5-7 bars range on peaks as well.
>
> It's a PEBCAK3 issue. ;-)
>
> --
>
> "The optimist proclaims that we live in the best of all
> possible worlds. The pessimist fears this is true."
>
> Web: https://www.n0nb.us
> Projects: https://github.com/N0NB
> GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819
>
> ______________________________________________________________
> Elecraft mailing list
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>

Bob McGraw - K4TAX

Re: K3--Too much ALC creates energy on opposite sideband?

In reply to this post by Wes Stewart-2

We've made great technical strides in receivers. Transmitters, well
they are best described still as "out house" technology. Nothing has
changed of significance in 25+ years. In looking at my P3 and SSB
signals on the bands, there are lots and lots of really bad signals.
Yet I most often hear "great signal" given as a report.

73

Bob, K4TAX

On 8/28/2019 3:50 PM, Wes wrote:

> Barry,
>
> With my SDR-IQ looking at the K3S i-f output I can see the other guy's
> signature. I suppose a P3 does the same. It's pretty amazing to see
> some of the lousy signals when we have such improved technology.
>
> Wes
>
> On 8/28/2019 1:30 PM, Barry wrote:
>> Wes,
>> You make a very good point. The unwanted sideband will not be 0;
>> there will be some "residue" that can be heard if the signal is
>> strong enough. And, a lot has to do with the measurement method at
>> the receiver.
>>
>> Years ago, I was running DSBSC using a Globe DSB-100. I was told
>> that my carrier was way down but my unwanted sideband was only 20 db
>> down. That was interesting as I made no effort to suppress my
>> unwanted sideband. The problem was the method that was used to make
>> the measurements and the strength of my signal. So, determining the
>> ratio of the two sidebands might be difficult, but it may be the
>> correct approach, However, it will require being able to "see" both
>> sidebands on an equal basis.
>>
>> 73,
>> Barry
>> K3NDM
>>
>> ------ Original Message ------
>> From: "Wes" <[hidden email]>
>> To: [hidden email]
>> Sent: 8/28/2019 1:45:11 PM
>> Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite
>> sideband?
>>
>>> Although the manual doesn't say so, according to an ARRL review, the
>>> K3S is specified to have undesired sideband suppression of >50 dB.
>>> ARRL claims an optimistic >70 dB.
>>>
>>> So if you are extremely strong at the other guy's place, he might
>>> easily hear an opposite sideband, even though your radio is
>>> operating correctly. Ask him what the ratio is.
>>>
>>> Wes N7WS
>>>
>>> On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>>>> I received a note this morning advising that I should check my ALC
>>>> as he
>>>> is seeing some energy on USB when I check into a 75m voice net on LSB.
>>>> I am using an MC-50 microphone and am running the mic gain at 35
>>>> and the
>>>> compression at 11. My thinking was that generating opposite sideband
>>>> energy would be quite difficult with the K3's DSP. Am I wrong?
>>>>
>>>> I'll try working with him some morning and back down the mic gain a
>>>> bit
>>>> and see what that does for him.
>>>>
>>>> 73, Nate, N0NB
>>>>
>>>
>>> ______________________________________________________________
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>>
>>
>
> ______________________________________________________________
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