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K3 cleanest signal possible

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Kjeld Holm

K3 cleanest signal possible

Dear all,

I have a K3/100 and an Acom 2000A and I am wondering how to get the cleanest
signal. The K3 is supplied with 13.8V.
I see several options. Adjusting the K3 to 9W thinking that the KPA100 does
not kick in could be one method. Another one could be adjusting the K3 to
14W thinking that the KPA100 will be running very easily (and clean). A
third one could be adjusting the K3 to 40W thinking that the KPA100 will be
running in the middle of its power range (and therefore being very clean).
I do not have the technical knowledge to decide which option is relevant.
Of course I know that the output from the Acom 2000A will vary very much
according to the selected output from the K3.
Vy 73 de OZ1CCM "Kel"

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Matt Zilmer-3

Re: K3 cleanest signal possible

Hi Kjeld,

One thing I do here is run the input voltage at 14.5V. The K3 can
accept up to 15V, and the 0.5V gives the power supply some margin for
overshoot.

This station is on solar power, so its "natural" voltage is 13.6V. I
use an N8XJK battery booster to get the 14.5V to the K3. The battery
is an Optima D-series, rated 75 AH.

The more voltage range the K3 works with, the better the IMD.

73,
matt
W6NIA

On Mon, 19 Jan 2015 18:10:57 +0100, you wrote:

>Dear all,
>
>I have a K3/100 and an Acom 2000A and I am wondering how to get the cleanest
>signal. The K3 is supplied with 13.8V.
>I see several options. Adjusting the K3 to 9W thinking that the KPA100 does
>not kick in could be one method. Another one could be adjusting the K3 to
>14W thinking that the KPA100 will be running very easily (and clean). A
>third one could be adjusting the K3 to 40W thinking that the KPA100 will be
>running in the middle of its power range (and therefore being very clean).
>I do not have the technical knowledge to decide which option is relevant.
>Of course I know that the output from the Acom 2000A will vary very much
>according to the selected output from the K3.
>Vy 73 de OZ1CCM "Kel"
>
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Matt Zilmer, W6NIA
--
"Give me six hours to chop down a tree and I will
spend the first four sharpening the axe." -A. Lincoln
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wayne burdick

Re: K3 cleanest signal possible

Administrator

In reply to this post by Kjeld Holm

Hi Kel,

The K3/100's phase noise and ALC artifacts are so low at all power levels that you shouldn't need to finesse this. I would select power level based on what you want to get out of the amp.

See W9YC's study of transmit phase noise and keying bandwidth of various transceivers:

http://audiosystemsgroup.com/TXNoise.pdf

73,
Wayne
N6KR

On Jan 19, 2015, at 9:10 AM, "Kjeld Holm" <[hidden email]> wrote:

Fred Townsend-2

Re: K3 cleanest signal possible

Wayne all I can say is wow! I knew the K3 was good but I had no idea it was
that much better. Let's hope the other manufactures adopt the most sincere
form of flattery... they copy the K3. After all that benefits all listeners.

My question relates to Matt's use of a battery booster. In theory this
allows the K3 to use maximum feedback and therefore have an even cleaner
signal. However my experience with battery boosters, not necessarily the one
Matt uses, is they are dirty in terms of electrical noise. The lower the
input voltage the dirtier they get. What is the K3s sensitivity to power
input noise. In short is the battery booster concept a net gain in terms of
spectral purity?

73
Fred, AE6QL

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Wayne
Burdick
Sent: Monday, January 19, 2015 9:22 AM
To: Kjeld Holm
Cc: [hidden email]
Subject: Re: [Elecraft] K3 cleanest signal possible

Hi Kel,

The K3/100's phase noise and ALC artifacts are so low at all power levels
that you shouldn't need to finesse this. I would select power level based on
what you want to get out of the amp.

See W9YC's study of transmit phase noise and keying bandwidth of various
transceivers:

http://audiosystemsgroup.com/TXNoise.pdf

73,
Wayne
N6KR

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Matt Zilmer-3

Re: K3 cleanest signal possible

Fred,

The N8XJK booster does put out a bit of RFI on HF. It's not enough to
cause problems here, but might be at an ultra low-noise QTH. I've
noticed this on receive, but haven't looked at TX spectral purity.
Wayne may have a definitive answer on this.

73,
matt
W6NIA

On Mon, 19 Jan 2015 10:15:41 -0800, you wrote:

>Wayne all I can say is wow! I knew the K3 was good but I had no idea it was
>that much better. Let's hope the other manufactures adopt the most sincere
>form of flattery... they copy the K3. After all that benefits all listeners.
>
>
>My question relates to Matt's use of a battery booster. In theory this
>allows the K3 to use maximum feedback and therefore have an even cleaner
>signal. However my experience with battery boosters, not necessarily the one
>Matt uses, is they are dirty in terms of electrical noise. The lower the
>input voltage the dirtier they get. What is the K3s sensitivity to power
>input noise. In short is the battery booster concept a net gain in terms of
>spectral purity?
>
>73
>Fred, AE6QL
>
>-----Original Message-----
>From: Elecraft [mailto:[hidden email]] On Behalf Of Wayne
>Burdick
>Sent: Monday, January 19, 2015 9:22 AM
>To: Kjeld Holm
>Cc: [hidden email]
>Subject: Re: [Elecraft] K3 cleanest signal possible
>
>Hi Kel,
>
>The K3/100's phase noise and ALC artifacts are so low at all power levels
>that you shouldn't need to finesse this. I would select power level based on
>what you want to get out of the amp.
>
>See W9YC's study of transmit phase noise and keying bandwidth of various
>transceivers:
>
> http://audiosystemsgroup.com/TXNoise.pdf
>
>73,
>Wayne
>N6KR
>
>
>______________________________________________________________
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Jim Brown-10

Re: K3 cleanest signal possible

In reply to this post by wayne burdick

On Mon,1/19/2015 9:21 AM, Wayne Burdick wrote:
> See W9YC's study of transmit phase noise and keying bandwidth of various transceivers:
>
> http://audiosystemsgroup.com/TXNoise.pdf

That document compares ARRL Lab measurements, all at full power.

I've also been doing some measurements of my own using a P3SVGA with my
second K3. They include measurements of a K3 driving both by KPA500 and
Ten Tec Titan legal limit tube amp. Test setup and methods are included
in the pdf.

k9yc.com/P3_SpectrumMeasurements.pdf

73, Jim K9YC
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wayne burdick

Re: K3 cleanest signal possible

Administrator

In reply to this post by wayne burdick

Correction: Jim Brown's call is K9YC.

Wayne

On Jan 19, 2015, at 9:21 AM, Wayne Burdick <[hidden email]> wrote:

> Hi Kel,
>
> The K3/100's phase noise and ALC artifacts are so low at all power levels that you shouldn't need to finesse this. I would select power level based on what you want to get out of the amp.
>
> See W9YC's study of transmit phase noise and keying bandwidth of various transceivers:
>
> http://audiosystemsgroup.com/TXNoise.pdf
>
> 73,
> Wayne
> N6KR

Clive Lorton

Re: K3 cleanest signal possible

In reply to this post by Fred Townsend-2

On 19/01/2015 18:15, Fred Townsend wrote:
> Wayne all I can say is wow! I knew the K3 was good but I had no idea it was
> that much better. Let's hope the other manufactures adopt the most sincere
> form of flattery... they copy the K3. After all that benefits all listeners
As a relative newcomer to the K3, about 9 months, all I can say is that
compared to my old Icom 756 I was not expecting to notice such a
noticeable improvement of weak signals replying to my call. I always had
complementary comments on the Icom's audio but the K3 just has that
extra je ne sais quoi that enables the DX to hear me.

Nothing else has changed except the K3

Thanks Guys

Clive G8POC
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Bill Frantz

Re: K3 cleanest signal possible

In reply to this post by Matt Zilmer-3

<http://www.w0qe.com/N8XJK_battery_booster.html> discusses
reducing the noise from the N8XJK battery booster. The author is
interested in a mobil application and is concerned about direct
noise pickup by the nearby antenna.

73 Bill AE6JV

On 1/19/15 at 10:25 AM, [hidden email] (Matt Zilmer) wrote:

>The N8XJK booster does put out a bit of RFI on HF. It's not enough to
>cause problems here, but might be at an ultra low-noise QTH. I've
>noticed this on receive, but haven't looked at TX spectral purity.
>Wayne may have a definitive answer on this.

-----------------------------------------------------------------------
Bill Frantz | I like the farmers' market | Periwinkle
(408)356-8506 | because I can get fruits and | 16345
Englewood Ave
www.pwpconsult.com | vegetables without stickers. | Los Gatos,
CA 95032

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k6dgw

Re: K3 cleanest signal possible

In reply to this post by Clive Lorton

So ... French has become the new English? ;-) For those who do not
speak French and haven't looked it up, je ne sais quoi is an unstated or
unknown something that makes something better.

For the record, using the Heil headset from Elecraft, I continue to get
unsolicited "great audio" comments in essentially every SSB contest I
enter. NAQP last Sat was the last. Never happened before the K3

Meanwhile, we continue to inch our way to metric ...

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
- www.cqp.org

On 1/19/2015 12:10 PM, Clive Lorton wrote:
> On 19/01/2015 18:15, Fred Townsend wrote:

> I always had
> complementary comments on the Icom's audio but the K3 just has that
> extra je ne sais quoi that enables the DX to hear me.

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Nate Bargmann

Re: K3 cleanest signal possible

* On 2015 19 Jan 16:32 -0600, Fred Jensen wrote:
> For the record, using the Heil headset from Elecraft, I continue to get
> unsolicited "great audio" comments in essentially every SSB contest I enter.
> NAQP last Sat was the last. Never happened before the K3

I have found the same with my K3/CM500 combination. I never received
compliments on my transmitted audio until I owned the K3. Yet, on
various forums the meme still exists that the K3 is a "poor SSB radio".
I've seen this comment a bit less, especially since firmware 4.51
improved the AGC noticeably. Other than distortion when engaging the
auto-notch, I am pleased enough that I am not contemplating replacing
the K3.

73, Nate N0NB

P.S. I claim that I have a face for radio and a voice for CW/digi modes!

--

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

Ham radio, Linux, bikes, and more: http://www.n0nb.us
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Stephen G4SJP

Re: K3 cleanest signal possible

If the K3 were supplied with a stock microphone, rather than leaving it to
the purchaser to potentially make a poor choice and then not bother to
compensate with the equaliser, I believe we wouldn't be reading these
admittedly isolated comments about K3s with "thin audio". This has
recently come up again with the current dxpedition in Iran.

I probably make fewer than a dozen SSB QSOs in a year, yet when I do I am
almost always complimented on the audio. I am using the MH2 microphone.

73 Stephen G4SJP

On 20 January 2015 at 00:24, Nate Bargmann <[hidden email]> wrote:

> * On 2015 19 Jan 16:32 -0600, Fred Jensen wrote:
> > For the record, using the Heil headset from Elecraft, I continue to get
> > unsolicited "great audio" comments in essentially every SSB contest I
> enter.
> > NAQP last Sat was the last. Never happened before the K3
>
> I have found the same with my K3/CM500 combination. I never received
> compliments on my transmitted audio until I owned the K3. Yet, on
> various forums the meme still exists that the K3 is a "poor SSB radio".
> I've seen this comment a bit less, especially since firmware 4.51
> improved the AGC noticeably. Other than distortion when engaging the
> auto-notch, I am pleased enough that I am not contemplating replacing
> the K3.
>
> 73, Nate N0NB
>
> P.S. I claim that I have a face for radio and a voice for CW/digi modes!
>
> --
>
> "The optimist proclaims that we live in the best of all
> possible worlds. The pessimist fears this is true."
>
> Ham radio, Linux, bikes, and more: http://www.n0nb.us
> ______________________________________________________________
> 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

Re: K3 cleanest signal possible

> If the K3 were supplied with a stock microphone <
> make a poor choice and then not bother to
compensate with the equaliser <

>> I probably make fewer than a dozen SSB QSOs in a year, yet when I do I amalmost always complimented on the audio. <<
>> > > For the record, using the Heil headset from Elecraft, I continue to get
> > unsolicited "great audio" comments in essentially every SSB contest I
> enter. << < <

It seems that there is a case of Apples and Oranges here.
The OP was more about Phase Noise that is emitted by the Radio.

Here is Wayne's response to the OP.
BTW, Jim's call should be K9YC as Wayne corrected later.

( See W9YC's study of transmit phase noise and keying bandwidth of various transceivers: http://audiosystemsgroup.com/TXNoise.pdf )
((((73)))) Milverton. / W9MMS

From: Stephen Prior <[hidden email]>
To: Elecraft <[hidden email]>
Sent: Tuesday, January 20, 2015 3:41 AM
Subject: Re: [Elecraft] K3 cleanest signal possible

If the K3 were supplied with a stock microphone, rather than leaving it to
the purchaser to potentially make a poor choice and then not bother to
compensate with the equaliser, I believe we wouldn't be reading these
admittedly isolated comments about K3s with "thin audio". This has
recently come up again with the current dxpedition in Iran.

I probably make fewer than a dozen SSB QSOs in a year, yet when I do I am
almost always complimented on the audio. I am using the MH2 microphone.

73 Stephen G4SJP

On 20 January 2015 at 00:24, Nate Bargmann <[hidden email]> wrote:

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gm3sek

Re: K3 cleanest signal possible

>The OP was more about Phase Noise that is emitted by the Radio.
>
>Here is Wayne's response to the OP.
>BTW, Jim's call should be K9YC as Wayne corrected later.
>
>( See W9YC's study of transmit phase noise and keying bandwidth of various
>transceivers: http://audiosystemsgroup.com/TXNoise.pdf )
>((((73)))) Milverton. / W9MMS
>

The discussion galloped off in the directions of phase noise and audio quality, but the OP didn't actually specify what he meant by "clean".

Had he mentioned IMD, the discussion might have gone differently. In static 2-tone tests, the K3's IMD performance is adequate for a "12V" transportable transceiver, but the high-order IMD is not very good at all (mostly due to the MOSFET driver).

However, the K3 pulls ahead again in dynamic IMD tests with real-life speech modulation, thanks to its almost unique "light touch" ALC system. The K3 implements ALC in the way that the engineers at Collins (the inventors of ALC for SSB) originally intended. The RF drive is pre-calibrated across a range of power levels on each band, leaving the ALC to deal with any moderate overshoots.

By contrast, most (all?) other transceivers still seem to use an ALC loop with very high gain to control the power level, band-to-band gain variations, clipping overshoots and "whatever else", and the high loop gain creates major dynamic overshoots of its own.

73 from Ian GM3SEK

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Jim Brown-10

Re: K3 cleanest signal possible

In reply to this post by Stephen G4SJP

On Tue,1/20/2015 1:41 AM, Stephen Prior wrote:
> If the K3 were supplied with a stock microphone, rather than leaving it to
> the purchaser to potentially make a poor choice and then not bother to
> compensate with the equaliser, I believe we wouldn't be reading these
> admittedly isolated comments about K3s with "thin audio". This has
> recently come up again with the current dxpedition in Iran.
>
> I probably make fewer than a dozen SSB QSOs in a year,

Those complaining about "thin audio" clearly don't know much about the
fundamentals of communications and speech intelligibility. It has been
well known for nearly a century that the frequency range that is most
important for speech intelligibility is 400 Hz to 4 kHz. It is also well
known that speech below 400 Hz wastes transmitter power. Those guys in
Iran SHOULD have "thin audio." I'd consider them incompetent if they did
not.

Ham radio is communications, not broadcasting. Many of us have done
both, and we know the difference. I'm a Fellow of the Audio Engineering
Society. My music recordings are full range. My ham transmissions are not.

73, Jim K9YC
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