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K3 receiver noise questionable test results

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Mike K2MK

K3 receiver noise questionable test results

I've hesitated to write because I don't have another rig to compare to my K3
and because I use a vertical antenna which is by its nature noisy. I always
have a high background noise level on all bands. I have NEVER experienced
what some have described as a dead quiet band with signals popping out.

My K3 is a year old with the latest firmware and all of the hardware mods. I
have not yet upgraded to a Rev C DSP board. I have tried various settings
for RF gain and AGC THR and SLP. I believe that I am proficient in making
these adjustments.

One test that I have performed leaves me scratching my head as to its
results. Maybe someone can enlighten me. I tune to a medium strength CW
signal and press my ANT button to switch between ANT 1 and ANT 2. I have
nothing connected to ANT 2. The signal disappears but the background noise
level remains the same.

73,
Mike K2MK

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Steve Ellington

Re: K3 receiver noise questionable test results

The isolation between ANT 1 and 2 isn't very good on mine either. If an 80m
cw signal is S7 to S9, I can still copy him just fine (s3) when switching to
the other ANT which has nothing connected. It might be 30db or so but you
would expect much more.
Steve
N4LQ
[hidden email]
----- Original Message -----
From: "K2MK" <[hidden email]>
To: "Elecraft Reflector" <[hidden email]>
Sent: Friday, December 18, 2009 8:39 AM
Subject: [Elecraft] K3 receiver noise questionable test results

> I've hesitated to write because I don't have another rig to compare to my
> K3
> and because I use a vertical antenna which is by its nature noisy. I
> always
> have a high background noise level on all bands. I have NEVER experienced
> what some have described as a dead quiet band with signals popping out.
>
> My K3 is a year old with the latest firmware and all of the hardware mods.
> I
> have not yet upgraded to a Rev C DSP board. I have tried various settings
> for RF gain and AGC THR and SLP. I believe that I am proficient in making
> these adjustments.
>
> One test that I have performed leaves me scratching my head as to its
> results. Maybe someone can enlighten me. I tune to a medium strength CW
> signal and press my ANT button to switch between ANT 1 and ANT 2. I have
> nothing connected to ANT 2. The signal disappears but the background noise
> level remains the same.
>
> 73,
> Mike K2MK
>
> ______________________________________________________________
> 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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> Please help support this email list: http://www.qsl.net/donate.html

--------------------------------------------------------------------------------

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M0XDF

Re: K3 receiver noise questionable test results

Have you tried connecting a dummy load to the other ant, or even
shorting the SO239 (carefully) to see if that make a difference?
73 de M0XDF, K3 #174
--
I think computer viruses should count as life. I think it says
something about human nature that the only form of life we have
created so far is purely destructive. We've created life in our own
image.
- Stephen Hawking

On 18 Dec 2009, at 13:49, Steve Ellington wrote:

> The isolation between ANT 1 and 2 isn't very good on mine either. If
> an 80m
> cw signal is S7 to S9, I can still copy him just fine (s3) when
> switching to
> the other ANT which has nothing connected. It might be 30db or so
> but you
> would expect much more.
> Steve
> N4LQ
> [hidden email]
> ----- Original Message -----
> From: "K2MK" <[hidden email]>
> To: "Elecraft Reflector" <[hidden email]>
> Sent: Friday, December 18, 2009 8:39 AM
> Subject: [Elecraft] K3 receiver noise questionable test results

Don Wilhelm-4

Re: K3 receiver noise questionable test results

In reply to this post by Mike K2MK

Mike,

That could easily happen if you have the AGC on. That would be
especially true if you have the preamp on when it is not needed and are
running the RF Gain at its full setting. With a signal present, the AGC
is acting to keep the receiver gain low, but when the signal is no
longer present, the receiver bounces back to full gain.

Try the same test with the AGC off and the preamp off (even with the
attenuator on) and the RF Gain backed down so the no-signal noise with
your vertical connected is just perceivable. Then tune in a signal,
note its strength and remove the antenna. The noise level should be
absent (unless you have the AF Gain set really high). If you still get
noise with no antenna, you have a receiver fault that needs attention.

73,
Don W3FPR

K2MK wrote:

> One test that I have performed leaves me scratching my head as to its
> results. Maybe someone can enlighten me. I tune to a medium strength CW
> signal and press my ANT button to switch between ANT 1 and ANT 2. I have
> nothing connected to ANT 2. The signal disappears but the background noise
> level remains the same.
>
> 73,
> Mike K2MK
>
>

Barry N1EU

Re: K3 receiver noise questionable test results

YES!!!! Don speaks the truth. Your K3 thinks you WANT it to amplify the heck out of everything in search of the weakest of signals and it is dutifully trying to do that.

Back down the value of AGC THR in the menu, turn down RF Gain, turn up your AF Gain and turn off your preamp on 160-20M.

73,
Barry N1EU

Don Wilhelm-4 wrote

Mike,

That could easily happen if you have the AGC on. That would be
especially true if you have the preamp on when it is not needed and are
running the RF Gain at its full setting. With a signal present, the AGC
is acting to keep the receiver gain low, but when the signal is no
longer present, the receiver bounces back to full gain.

Try the same test with the AGC off and the preamp off (even with the
attenuator on) and the RF Gain backed down so the no-signal noise with
your vertical connected is just perceivable. Then tune in a signal,
note its strength and remove the antenna. The noise level should be
absent (unless you have the AF Gain set really high). If you still get
noise with no antenna, you have a receiver fault that needs attention.

73,
Don W3FPR

K2MK wrote:
> One test that I have performed leaves me scratching my head as to its
> results. Maybe someone can enlighten me. I tune to a medium strength CW
> signal and press my ANT button to switch between ANT 1 and ANT 2. I have
> nothing connected to ANT 2. The signal disappears but the background noise
> level remains the same.
>
> 73,
> Mike K2MK
>
>
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AD4C2009

K3 audio files

In reply to this post by Don Wilhelm-4

I will like to help to this very insteresting discussion about noisy K3 but I need some one who volunteer a website where I could up load about 80MB of MP3 files that I have saved when recording SSB and CW stations in pileups,dx,ragchewing,with and without the antenna,with and without NR,etc that will show you how quite is my K3 receiver,so let me know where I can keep those audio files for you to download.

AD4C

"For a refined ham it is compulsory to own a k3"

--- On Fri, 12/18/09, Don Wilhelm <[hidden email]> wrote:

From: Don Wilhelm <[hidden email]>
Subject: Re: [Elecraft] K3 receiver noise questionable test results
To: "K2MK" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Date: Friday, December 18, 2009, 2:01 PM

Mike,

That could easily happen if you have the AGC on. That would be
especially true if you have the preamp on when it is not needed and are
running the RF Gain at its full setting. With a signal present, the AGC
is acting to keep the receiver gain low, but when the signal is no
longer present, the receiver bounces back to full gain.

Try the same test with the AGC off and the preamp off (even with the
attenuator on) and the RF Gain backed down so the no-signal noise with
your vertical connected is just perceivable. Then tune in a signal,
note its strength and remove the antenna. The noise level should be
absent (unless you have the AF Gain set really high). If you still get
noise with no antenna, you have a receiver fault that needs attention.

73,
Don W3FPR

K2MK wrote:

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Mike K2MK

Re: K3 receiver noise questionable test results

In reply to this post by Don Wilhelm-4

Hi Don:

First I tried actually removing the antenna at the SO239 connector in case
it was an issue of isolation suggested by N4LQ. This provided some minor
reduction in background noise. So obviously some of the noise is coming in
on the antenna.

Following your suggestion I tuned in a S5 level CW signal on 40 meters with
AGC OFF and ATT ON. I reduced the RF gain to eliminate the noise but that
also eliminated the signal. In order to copy this normal level signal I must
have some accompanying level of background noise.

With an S9 or greater signal I can reduce either the RF gain or the AF gain
and be free of background noise. Sometimes an S7 signal will suffice.

The same affect is present in my Sub RX.

After reading the many posts describing RX noise, I don't think I have a RX
fault. I think my K3 is experiencing what the others have been posting
about. The background noise is not extreme. It's just always there.

73,
Mike K2MK

--------------------------------------------------
From: "Don Wilhelm" <[hidden email]>
Sent: Friday, December 18, 2009 9:01 AM
To: "K2MK" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Subject: Re: [Elecraft] K3 receiver noise questionable test results

> Mike,
>
> That could easily happen if you have the AGC on. That would be especially
> true if you have the preamp on when it is not needed and are running the
> RF Gain at its full setting. With a signal present, the AGC is acting to
> keep the receiver gain low, but when the signal is no longer present, the
> receiver bounces back to full gain.
>
> Try the same test with the AGC off and the preamp off (even with the
> attenuator on) and the RF Gain backed down so the no-signal noise with
> your vertical connected is just perceivable. Then tune in a signal, note
> its strength and remove the antenna. The noise level should be absent
> (unless you have the AF Gain set really high). If you still get noise
> with no antenna, you have a receiver fault that needs attention.
>
> 73,
> Don W3FPR
>
> K2MK wrote:
>> One test that I have performed leaves me scratching my head as to its
>> results. Maybe someone can enlighten me. I tune to a medium strength CW
>> signal and press my ANT button to switch between ANT 1 and ANT 2. I have
>> nothing connected to ANT 2. The signal disappears but the background
>> noise level remains the same.
>>
>> 73,
>> Mike K2MK
>

P.B. Christensen

Re: K3 receiver noise questionable test results

In reply to this post by Barry N1EU

> Back down the value of AGC THR in the menu, turn down RF Gain, turn up
> your
> AF Gain and turn off your preamp on 160-20M.

Adding to that...AGC SLP has a profound effect on the AGC compression ratio.
Higher settings make all signals sound relatively the same. A few posts
back, I recall seeing comments about how signals on a Yaesu transceiver
seemed to "pop out." For that to noticeably happen on the K3, AGC SLP will
need to be set for lower menu values. From the K3 manual:

AGC SLP - (Advanced.) Higher values result in 'flatter' AGC (making signals
at all amplitudes closer in AF output level)." My AGC SLP setting is on the
lower end of the range as I actually prefer audio dynamic range rather than
homogenizing everything on the band.

Aggressive AGC SLP and AGC THR add to a perceived increase in background
noise and signals that do not "pop out."

Paul, W9AC

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John_N1JM

Re: K3 receiver noise questionable test results

It seems as I move the value of AGC SLP down the noise gets louder. Does that sound right?

John N1JM

P.B. Christensen wrote

> Back down the value of AGC THR in the menu, turn down RF Gain, turn up
> your
> AF Gain and turn off your preamp on 160-20M.

Adding to that...AGC SLP has a profound effect on the AGC compression ratio.
Higher settings make all signals sound relatively the same. A few posts
back, I recall seeing comments about how signals on a Yaesu transceiver
seemed to "pop out." For that to noticeably happen on the K3, AGC SLP will
need to be set for lower menu values. From the K3 manual:

AGC SLP - (Advanced.) Higher values result in 'flatter' AGC (making signals
at all amplitudes closer in AF output level)." My AGC SLP setting is on the
lower end of the range as I actually prefer audio dynamic range rather than
homogenizing everything on the band.

Aggressive AGC SLP and AGC THR add to a perceived increase in background
noise and signals that do not "pop out."

Paul, W9AC

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Barry N1EU

Re: K3 receiver noise questionable test results

That result indicates you have too much RF/IF Gain. You need to apply the remedies previously discussed.

73,
Barry N1EU

N1JM wrote

It seems as I move the value of AGC SLP down the noise gets louder. Does that sound right?

John N1JM

P.B. Christensen wrote

> Back down the value of AGC THR in the menu, turn down RF Gain, turn up
> your
> AF Gain and turn off your preamp on 160-20M.

Adding to that...AGC SLP has a profound effect on the AGC compression ratio.
Higher settings make all signals sound relatively the same. A few posts
back, I recall seeing comments about how signals on a Yaesu transceiver
seemed to "pop out." For that to noticeably happen on the K3, AGC SLP will
need to be set for lower menu values. From the K3 manual:

AGC SLP - (Advanced.) Higher values result in 'flatter' AGC (making signals
at all amplitudes closer in AF output level)." My AGC SLP setting is on the
lower end of the range as I actually prefer audio dynamic range rather than
homogenizing everything on the band.

Aggressive AGC SLP and AGC THR add to a perceived increase in background
noise and signals that do not "pop out."

Paul, W9AC

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Mike Harris

Re: K3 receiver noise questionable test results

In reply to this post by Steve Ellington

G'day,

I think that 30dB isolation across a single small PCB mounted relay
is about as good as it gets. It's the same for the K2 ATU's.

Regards,

Mike VP8NO

----- Original Message -----
From: "Steve Ellington" <[hidden email]>
To: "K2MK" <[hidden email]>; "Elecraft Reflector"
<[hidden email]>
Sent: Friday, December 18, 2009 10:49 AM
Subject: Re: [Elecraft] K3 receiver noise questionable test results

> The isolation between ANT 1 and 2 isn't very good on mine either.
> If an 80m
> cw signal is S7 to S9, I can still copy him just fine (s3) when
> switching to
> the other ANT which has nothing connected. It might be 30db or so
> but you
> would expect much more.
> Steve
> N4LQ

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PD2R

Re: K3 audio files

In reply to this post by AD4C2009

Hector,

I have listened to one of your audio files, the one you send to PD2DX (who
was operating at PI4DX) last weekend. I know that my K3 just doesn't sound
like that. It's close, but not quiet there. I have tried several settings
with the help of K8OAZ pdf file on how to set the AGC. This has improved the
radio a lot but it still prefer the sound of my friends IC 7700. Ik know the
K3 can sound just as good but I still haven't been able to figure out how to
do it.
I find this tread very helpful to help me understand how K3 works and maybe
one day find the right settings for me.

73, Maarten
PD2R

2009/12/18 Hector Padron <[hidden email]>

>
>
>
>
>
>
>
>
>
>
>
>
>
>
> I will like to help to this very insteresting discussion about noisy K3 but
> I need some one who volunteer a website where I could up load about 80MB of
> MP3 files that I have saved when recording SSB and CW stations in
> pileups,dx,ragchewing,with and without the antenna,with and without NR,etc
> that will show you how quite is my K3 receiver,so let me know where I
> can keep those audio files for you to download.
>
> AD4C
>
>
> "For a refined ham it is compulsory to own a k3"
>
> --- On Fri, 12/18/09, Don Wilhelm <[hidden email]> wrote:
>
>
> From: Don Wilhelm <[hidden email]>
> Subject: Re: [Elecraft] K3 receiver noise questionable test results
> To: "K2MK" <[hidden email]>
> Cc: "Elecraft Reflector" <[hidden email]>
> Date: Friday, December 18, 2009, 2:01 PM
>
>
> Mike,
>
> That could easily happen if you have the AGC on. That would be
> especially true if you have the preamp on when it is not needed and are
> running the RF Gain at its full setting. With a signal present, the AGC
> is acting to keep the receiver gain low, but when the signal is no
> longer present, the receiver bounces back to full gain.
>
> Try the same test with the AGC off and the preamp off (even with the
> attenuator on) and the RF Gain backed down so the no-signal noise with
> your vertical connected is just perceivable. Then tune in a signal,
> note its strength and remove the antenna. The noise level should be
> absent (unless you have the AF Gain set really high). If you still get
> noise with no antenna, you have a receiver fault that needs attention.
>
> 73,
> Don W3FPR
>
> K2MK wrote:
> > One test that I have performed leaves me scratching my head as to its
> > results. Maybe someone can enlighten me. I tune to a medium strength CW
> > signal and press my ANT button to switch between ANT 1 and ANT 2. I have
> > nothing connected to ANT 2. The signal disappears but the background
> noise
> > level remains the same.
> >
> > 73,
> > Mike K2MK
> >
> >
> ______________________________________________________________
> 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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> Please help support this email list: http://www.qsl.net/donate.html
>

Maarten, PD2R
Member of the PI4DX contest group
www.pi4dx.com

Elecraft K3 nr:1849

alorona

Re: K3 receiver noise questionable test results

In reply to this post by P.B. Christensen

I have been frustrated by the lack of measurements that we can hold on to as we discuss the noisy K3 receiver that many folks are reporting.

Help me out here: are we talking about the *amount* of noise, or the *character* of the noise? I don't even think we've established the answer to this.

If it's the amount of noise that folks are hearing, wouldn't you just turn the gain down to match your Other receiver? No two receivers have the same amount of gain, and I think this point has been lost on some of us.

If it's the character of the noise, and if you find it objectionable, and if no settings of gain, filtering or noise reduction change it, I'd say it's time to go back to the Other receiver, and I'm not being facetious about this.

But in lieu of measured data, let's ask the folks with noisy K3 receivers a few empirical questions:

1. Set up your K3 and your favorite Other receiver to receive the same band noise. Set them up like you usually do: AF gain, RF gain, etc. Note the noise level of the Other receiver... don't look at S-meters, voltmeters, etc., just memorize the noise.

Now switch to the K3 and go into the CONFIG menu.

a. Is there any setting of AGC THR that gives you the same noise as Other?

If so, use it.

If not, proceed to step b.

b. Is there any setting of AGC SLP that gives you the same noise as Other?

If so, use it.

If not, I don't know what to tell you.

Actually, there might be a possible Step c., and that would be to adjust the RF gain on the K3 to match Other.

Al W6LX
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Don Wilhelm-4

Re: K3 receiver noise questionable test results

Al,

Your points are well taken, But a few of the K3 owners that have
pro-audio instrumentation have reported that the K3 audio response is
more like 'white noise' (a flat response), as opposed to other receivers
which have a 'pink noise' audio spectrum. That says that the K3 more
faithfully reproduces any noise on the band, but that noise faithfully
reproduced can be more irritating than receivers that have a 'pink
noise' audio spectrum response.

I believe that we are hearing a variety of responses, and unfortunately,
it is difficult to interpret and de-cipher the real source of each
person's perception, so we are offering several suggestions, but it is
like 'spitting into the wind' because we are not clear what the target
really is.

73,
Don W3FPR

Al Lorona wrote:

> I have been frustrated by the lack of measurements that we can hold on to as we discuss the noisy K3 receiver that many folks are reporting.
>
> Help me out here: are we talking about the *amount* of noise, or the *character* of the noise? I don't even think we've established the answer to this.
>
> If it's the amount of noise that folks are hearing, wouldn't you just turn the gain down to match your Other receiver? No two receivers have the same amount of gain, and I think this point has been lost on some of us.
>
> If it's the character of the noise, and if you find it objectionable, and if no settings of gain, filtering or noise reduction change it, I'd say it's time to go back to the Other receiver, and I'm not being facetious about this.
>
> But in lieu of measured data, let's ask the folks with noisy K3 receivers a few empirical questions:
>
> 1. Set up your K3 and your favorite Other receiver to receive the same band noise. Set them up like you usually do: AF gain, RF gain, etc. Note the noise level of the Other receiver... don't look at S-meters, voltmeters, etc., just memorize the noise.
>
> Now switch to the K3 and go into the CONFIG menu.
>
> a. Is there any setting of AGC THR that gives you the same noise as Other?
>
> If so, use it.
>
> If not, proceed to step b.
>
> b. Is there any setting of AGC SLP that gives you the same noise as Other?
>
> If so, use it.
>
> If not, I don't know what to tell you.
>
> Actually, there might be a possible Step c., and that would be to adjust the RF gain on the K3 to match Other.
>
>

Steve Ellington

Re: K3 receiver noise questionable test results

One can easily use a fatigueometer to quantify these complaints.
Fatigueometers are calibrated in F units.
Typically, we would connect the F meter across the receiver's AF output
along with a "Popoutometer".
The P meter accurately measures the degree in which signals "pop out" of the
noise. A high number of P's is desirable.
Once these numbers are obtained we apply the formula, G=P/F
Where G = Goodness, P = Popouts units in poppiemites and F= Fatigue units
in fatigueamites
After years of frustration, trying to evaluate radios by ear, I finally
broke down and purchased both meters.
Don't bother asking me where you can purchase these. You can't afford them.
If you would like for me to evaluate your radio, ship it to me. I will
evaluate carefully and send you a full report.
The radio will be considered payment for my services.
73
Steve
N4LQ
[hidden email]
----- Original Message -----
From: "Don Wilhelm" <[hidden email]>
To: "Al Lorona" <[hidden email]>
Cc: <[hidden email]>
Sent: Friday, December 18, 2009 9:22 PM
Subject: Re: [Elecraft] K3 receiver noise questionable test results

> Al,
>
> Your points are well taken, But a few of the K3 owners that have
> pro-audio instrumentation have reported that the K3 audio response is
> more like 'white noise' (a flat response), as opposed to other receivers
> which have a 'pink noise' audio spectrum. That says that the K3 more
> faithfully reproduces any noise on the band, but that noise faithfully
> reproduced can be more irritating than receivers that have a 'pink
> noise' audio spectrum response.
>
> I believe that we are hearing a variety of responses, and unfortunately,
> it is difficult to interpret and de-cipher the real source of each
> person's perception, so we are offering several suggestions, but it is
> like 'spitting into the wind' because we are not clear what the target
> really is.
>
> 73,
> Don W3FPR
>
> Al Lorona wrote:
>> I have been frustrated by the lack of measurements that we can hold on to
>> as we discuss the noisy K3 receiver that many folks are reporting.
>>
>> Help me out here: are we talking about the *amount* of noise, or the
>> *character* of the noise? I don't even think we've established the answer
>> to this.
>>
>> If it's the amount of noise that folks are hearing, wouldn't you just
>> turn the gain down to match your Other receiver? No two receivers have
>> the same amount of gain, and I think this point has been lost on some of
>> us.
>>
>> If it's the character of the noise, and if you find it objectionable, and
>> if no settings of gain, filtering or noise reduction change it, I'd say
>> it's time to go back to the Other receiver, and I'm not being facetious
>> about this.
>>
>> But in lieu of measured data, let's ask the folks with noisy K3 receivers
>> a few empirical questions:
>>
>> 1. Set up your K3 and your favorite Other receiver to receive the same
>> band noise. Set them up like you usually do: AF gain, RF gain, etc. Note
>> the noise level of the Other receiver... don't look at S-meters,
>> voltmeters, etc., just memorize the noise.
>>
>> Now switch to the K3 and go into the CONFIG menu.
>>
>> a. Is there any setting of AGC THR that gives you the same noise as
>> Other?
>>
>> If so, use it.
>>
>> If not, proceed to step b.
>>
>> b. Is there any setting of AGC SLP that gives you the same noise as
>> Other?
>>
>> If so, use it.
>>
>> If not, I don't know what to tell you.
>>
>> Actually, there might be a possible Step c., and that would be to adjust
>> the RF gain on the K3 to match Other.
>>
>>
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alorona

Re: K3 receiver noise questionable test results

In reply to this post by Don Wilhelm-4

> But a few of the K3 owners that have pro-audio
> instrumentation have reported that the K3 audio
> response is more like 'white noise' (a flat response),
>as opposed to other receivers which have a 'pink
> noise' audio spectrum.

If that's the case, then the K3's receiver equalizer can be set up to mimic a pink rolloff which is -3 dB per octave.

50 Hz    :    + 9 dB
100    :    + 6
200    :    + 3
400    :    0
800    :    - 3
1600    :    - 6
3200    :    - 9

or if 3 dB per octave is a little severe, then one could try 2 dB per.

This is awfully conjectural until we can quantify exactly what it is that a Yaesu FT-1000 has that a K3 doesn't.

One of the guys at work has pasted on his cubicle wall that famous quote of Lord Kelvin that I believe applies here:
When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge of it is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced it to the stage of science.
Sir William Thompson, Lord Kelvin (1824-1907)
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Alexandr Kobranov

Re: K3 receiver noise questionable test results

In reply to this post by Barry N1EU

Please keep in mind there is also one factor (not mentioned yet maybe) -
setting of the additional gain related to particular filter (FLx). My
experience is that less is more and this factor has - for me - influence to
overall "sound".
When anybody is reporting AGC parameters, RX EQ settings etc. maybe this
setting is also good to publish for complete picture.
Just to remind,

all the best and 73!

Lexa, OK1DST
K3/10 #727
(just waitnig for 100W module to upgrade :-))

2009/12/18 Barry N1EU <[hidden email]>

>
> That result indicates you have too much RF/IF Gain. You need to apply the
> remedies previously discussed.
>
> 73,
> Barry N1EU
>
>
>
>

Mike Harris

Re: K3 receiver noise questionable test results

In reply to this post by alorona

G'day,

Please correct me if I'm wrong but my understanding is that the
settings of the RX equaliser work within the DSP block and will do
little to suppress the higher frequency products that contaminate
the subsequent audio out of the DAC. This is the domain of the
analogue LPF module that has finally emerged kicking and screaming.

Regards,

Mike VP8NO

----- Original Message -----
From: "Al Lorona" <[hidden email]>
Cc: <[hidden email]>
Sent: Saturday, December 19, 2009 3:40 AM
Subject: Re: [Elecraft] K3 receiver noise questionable test results

> But a few of the K3 owners that have pro-audio
> instrumentation have reported that the K3 audio
> response is more like 'white noise' (a flat response),
>as opposed to other receivers which have a 'pink
> noise' audio spectrum.

If that's the case, then the K3's receiver equalizer can be set up
to mimic a pink rolloff which is -3 dB per octave.

50 Hz : + 9 dB
100 : + 6
200 : + 3
400 : 0
800 : - 3
1600 : - 6
3200 : - 9

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AD4C2009

Re: K3 receiver noise questionable test results

In reply to this post by alorona

If this help others to improve their receivers I am going to share here all my settings.
My K3 # 2192 is very quite,let say first that over my home at 40 feet is running a Florida Power and Light 33KV line and I have around my K3 three computers running all the time,nevertheless I have very low noise in the receiver,its completeley clean,so I have it set this way:
AGC DCY.....SOFT
AGC HLD     0.20
AGC PLS     nor
AGC SLP     015
AGC THR     005
AGC-F         150
AGC-S         020
FL2 BW       2.8
FL2 FRQ      0.00
FL2 GN        0
FW             3.63
RX EQ :
50Hz           +12
100Hz         +8
200Hz         +2
400Hz          0
800Hz          0
1600Hz        0
2400            0
3200          --16 (minus)
My DSP board was mod by Elecraft with the W9AC hardware changes for wider audio bandwith.With all these settings my working RX bandwith is from 60 to 2700Hz.
I normally use the AGC always in ON at the slow position,the Audio vol control at 50% and the RF gain control at 50% or less just what needed to pull the station clear.
I can share MP3 files with anyone interested to hear how quite is my receiver.
This discussion about K3 noisy receivers is been very positive because we have all learned more about our radio and we can share each other better settings to improve the receiver noise level.Nobody should be stoped to writte their opinion.Certainly the complainers are very few compared with the thousand of happy K3 owners who are pretty satisfied with the receiver but everybody has the right to say what they feel.
My two cents.
Merry xmas for all and hoping the new year will bring us more happiness,health and luck.

AD4C

"For a refined ham it is compulsory to own a k3"

--- On Sat, 12/19/09, Al Lorona <[hidden email]> wrote:

From: Al Lorona <[hidden email]>
Subject: Re: [Elecraft] K3 receiver noise questionable test results
To:
Cc: [hidden email]
Date: Saturday, December 19, 2009, 6:40 AM

> But a few of the K3 owners that have pro-audio
> instrumentation have reported that the K3 audio
> response is more like 'white noise' (a flat response),
>as opposed to other receivers which have a 'pink
> noise' audio spectrum.

If that's the case, then the K3's receiver equalizer can be set up to mimic a pink rolloff which is -3 dB per octave.

50 Hz    :    + 9 dB
100    :    + 6
200    :    + 3
400    :    0
800    :    - 3
1600    :    - 6
3200    :    - 9

or if 3 dB per octave is a little severe, then one could try 2 dB per.

This is awfully conjectural until we can quantify exactly what it is that a Yaesu FT-1000 has that a K3 doesn't.

One of the guys at work has pasted on his cubicle wall that famous quote of Lord Kelvin that I believe applies here:
When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge of it is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced it to the stage of science.
Sir William Thompson, Lord Kelvin (1824-1907)
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K2QI

Re: K3 receiver noise questionable test results

In reply to this post by alorona

Greetings Al et all,

In my case, I experience a significant amount of high-frequency white noise.
I'm not sure if that's the best way to describe it. Think of the
high-pitched whine you'd hear if you're travelling inside an airplane.
Adjusting AGC, gain, and even RX EQ settings don't have much of an effect.
If anything, adjusting AGC and gain controls just seem to reduce volume but
not actual audio characteristic.

73 de James K2QI

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Al Lorona
Sent: Friday, December 18, 2009 9:07 PM
To: [hidden email]
Subject: Re: [Elecraft] K3 receiver noise questionable test results

<snip>

Help me out here: are we talking about the *amount* of noise, or the
*character* of the noise? I don't even think we've established the answer to
this.

If it's the amount of noise that folks are hearing, wouldn't you just turn
the gain down to match your Other receiver? No two receivers have the same
amount of gain, and I think this point has been lost on some of us.

If it's the character of the noise, and if you find it objectionable, and if
no settings of gain, filtering or noise reduction change it, I'd say
it's time to go back to the Other receiver, and I'm not being facetious
about this.

<snip>

Al W6LX
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