Elecraft

DSP and IF Filters

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Ron Edmon

DSP and IF Filters

I have been going through the manual on the K3 trying different combination
of DSP and IF as well as NR filters trying to reduce atmospheric noise. I
find the noise level to high pitched which fatigues me after an hour or so
of listening. I've listened to the "Hear It" external DSP filter employed
on a friends ten-tec rig and the reduction of atmospheric noise is
significant (1 "S" unit or better). Shouldn't the K3 DSP filter be capable
of reducing the atmospheric noise to acceptable levels?

Ron, N6SC

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Guy, K2AV

Re: DSP and IF Filters

A precise definition of what you mean by "atmospheric noise"? And were you
talking about effectively "rolling off" higher frequencies or were you
talking about cancellation?

One definition of "atmospheric noise includes both close and distant
lightning static or QRN, including from another continent.

In all my years I have never seen a verified reduction of signal-to-noise
from QRN that didn't amount to reducing bandwidth, which still works no
better now than it did in 1955.

Careful work with levels and SNR always exposes the truth from "sounds
better". Sounding more "pleasant" does not mean you will communicate better
in a contest. You'll just feel better doing the same thing.

Not that I haven't been listening and hoping all that time. PLEASE, PLEASE
don't prove me wrong!

73, Guy.

----- Original Message -----
From: "Ron Edmon" <[hidden email]>
To: <[hidden email]>
Sent: Friday, June 19, 2009 10:40 PM
Subject: [Elecraft] DSP and IF Filters

>I have been going through the manual on the K3 trying different combination
> of DSP and IF as well as NR filters trying to reduce atmospheric noise. I
> find the noise level to high pitched which fatigues me after an hour or so
> of listening. I've listened to the "Hear It" external DSP filter employed
> on a friends ten-tec rig and the reduction of atmospheric noise is
> significant (1 "S" unit or better). Shouldn't the K3 DSP filter be
> capable
> of reducing the atmospheric noise to acceptable levels?
>
> Ron, N6SC
>
>
> ______________________________________________________________
> 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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Merv Schweigert

Re: DSP and IF Filters

Cannot say what Rons definition of the noise is, but mine is the higher
pitched sound
of the radio without QRN and a noise level of S1 to S2 on the meter,
but I find its
easy to find a comfortable listening "pitch" by just using the shift
and a couple clicks
down the passband and the high pitch is gone. For instance the FC* on
mine says
.60 and if I move the shift down to .50 or .40 the high pitch is gone.
Have never found a setting on NR that has worked for me, others have
better luck.
73 Merv KH7C

> A precise definition of what you mean by "atmospheric noise"? And were you
> talking about effectively "rolling off" higher frequencies or were you
> talking about cancellation?
>
> One definition of "atmospheric noise includes both close and distant
> lightning static or QRN, including from another continent.
>
> In all my years I have never seen a verified reduction of signal-to-noise
> from QRN that didn't amount to reducing bandwidth, which still works no
> better now than it did in 1955.
>
> Careful work with levels and SNR always exposes the truth from "sounds
> better". Sounding more "pleasant" does not mean you will communicate better
> in a contest. You'll just feel better doing the same thing.
>
> Not that I haven't been listening and hoping all that time. PLEASE, PLEASE
> don't prove me wrong!
>
> 73, Guy.
>
> ----- Original Message -----
> From: "Ron Edmon" <[hidden email]>
> To: <[hidden email]>
> Sent: Friday, June 19, 2009 10:40 PM
> Subject: [Elecraft] DSP and IF Filters
>
>
>
>> I have been going through the manual on the K3 trying different combination
>> of DSP and IF as well as NR filters trying to reduce atmospheric noise. I
>> find the noise level to high pitched which fatigues me after an hour or so
>> of listening. I've listened to the "Hear It" external DSP filter employed
>> on a friends ten-tec rig and the reduction of atmospheric noise is
>> significant (1 "S" unit or better). Shouldn't the K3 DSP filter be
>> capable
>> of reducing the atmospheric noise to acceptable levels?
>>
>> Ron, N6SC
>>
>>
>> ______________________________________________________________
>> 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
>
>

Ron Edmon

Re: DSP and IF Filters

Merv,

Interesting, I have used the shift and on my unit the FC* is at 150. I find
moving it down to 90 helps (toning down the higher pitches noise) as well as
playing with the bandwidth (trial and re-trial). Noise seems to be about S3
in my area with no improvement or reduction in noise using DSP (both IF's)
or using Noise Reduction at any of the settings. NR seems to be pretty
ineffective unless it's just operator error but, I think I have a fair
understanding of going through the settings while listening to the
atmospheric noise..

Thanks for your comments,

Ron N6SC

_____

From: Merv Schweigert [mailto:[hidden email]]
Sent: Saturday, June 20, 2009 4:11 PM
To: Guy Olinger, K2AV
Cc: Ron Edmon; [hidden email]
Subject: Re: [Elecraft] DSP and IF Filters

Cannot say what Rons definition of the noise is, but mine is the higher
pitched sound
of the radio without QRN and a noise level of S1 to S2 on the meter, but I
find its
easy to find a comfortable listening "pitch" by just using the shift and a
couple clicks
down the passband and the high pitch is gone. For instance the FC* on mine
says
.60 and if I move the shift down to .50 or .40 the high pitch is gone.
Have never found a setting on NR that has worked for me, others have better
luck.
73 Merv KH7C

A precise definition of what you mean by "atmospheric noise"? And were you
talking about effectively "rolling off" higher frequencies or were you
talking about cancellation?

One definition of "atmospheric noise includes both close and distant
lightning static or QRN, including from another continent.

In all my years I have never seen a verified reduction of signal-to-noise
from QRN that didn't amount to reducing bandwidth, which still works no
better now than it did in 1955.

Careful work with levels and SNR always exposes the truth from "sounds
better". Sounding more "pleasant" does not mean you will communicate better

in a contest. You'll just feel better doing the same thing.

Not that I haven't been listening and hoping all that time. PLEASE, PLEASE
don't prove me wrong!

73, Guy.

----- Original Message -----
From: "Ron Edmon" <mailto:[hidden email]> <[hidden email]>
To: <mailto:[hidden email]> <[hidden email]>
Sent: Friday, June 19, 2009 10:40 PM
Subject: [Elecraft] DSP and IF Filters

I have been going through the manual on the K3 trying different combination
of DSP and IF as well as NR filters trying to reduce atmospheric noise. I
find the noise level to high pitched which fatigues me after an hour or so
of listening. I've listened to the "Hear It" external DSP filter employed
on a friends ten-tec rig and the reduction of atmospheric noise is
significant (1 "S" unit or better). Shouldn't the K3 DSP filter be
capable
of reducing the atmospheric noise to acceptable levels?

Ron, N6SC

______________________________________________________________
Elecraft mailing list
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______________________________________________________________
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______________________________________________________________
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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