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Noisy RX redux

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Mike Reublin

Noisy RX redux

Shortly after I got K3 3935 in Sept. of '09, the furor over noisy RX kinda peaked, and the result was a board swap.

A friend just bought a used K3 with a slightly earlier SN, and the RX background is very harsh and sharp sounding. We both came to Elecraft from a PRO II/III where the background in an A/B comparison is a soft swhoooooooooooosh.

I'd like to check and see if it has the same mod, but I've slept since then and cannot remember what the mod was called, or how to check for it. A tour of the mods page didn't kick my recaller into gear.

A related wish: List the serial number when a mod goes into production.

n unrelated wish: HAPPY 4th!

73, Mike NF4L

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Don Wilhelm-4

Re: Noisy RX redux

Mike,

The audio low pass filter that was added to the DSP board do make a big
improvement in the K3 perceived noise.

The AGC settings have a lot to do with that condition too, and I believe
the default settings do not give he best performance, but your
particular antenna and noise level have a lot to do with it as well.

Please check out the "Noisy K3" article on my website www.w3fpr.com for
information in adjusting the AGC parameters to better suit your
particular situation.

73,
Don W3FPR

On 7/4/2013 5:47 PM, Mike Reublin wrote:

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Mike Reublin

Re: Noisy RX redux

In reply to this post by Mike Reublin

Thanks, Don.

I played around with the AGC settings as you describe, and I can't say I found settings that made a difference. But I do have a tin ear.

You don't happen to remember where the DSP board mod is on the website, do you?

Mike

On Jul 4, 2013, at 5:47 PM, Mike Reublin <[hidden email]> wrote:

> Shortly after I got K3 3935 in Sept. of '09, the furor over noisy RX kinda peaked, and the result was a board swap.
>
> A friend just bought a used K3 with a slightly earlier SN, and the RX background is very harsh and sharp sounding. We both came to Elecraft from a PRO II/III where the background in an A/B comparison is a soft swhoooooooooooosh.
>
> I'd like to check and see if it has the same mod, but I've slept since then and cannot remember what the mod was called, or how to check for it. A tour of the mods page didn't kick my recaller into gear.
>
> A related wish: List the serial number when a mod goes into production.
>
> n unrelated wish: HAPPY 4th!
>
> 73, Mike NF4L
>
>
>
> ______________________________________________________________
> 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

Mike Reublin

Re: Noisy RX redux

I found the mod.

On Jul 4, 2013, at 6:38 PM, Mike Reublin <[hidden email]> wrote:

> Thanks, Don.
>
> I played around with the AGC settings as you describe, and I can't say I found settings that made a difference. But I do have a tin ear.
>
> You don't happen to remember where the DSP board mod is on the website, do you?
>
> Mike
>
> On Jul 4, 2013, at 5:47 PM, Mike Reublin <[hidden email]> wrote:
>
>> Shortly after I got K3 3935 in Sept. of '09, the furor over noisy RX kinda peaked, and the result was a board swap.
>>
>> A friend just bought a used K3 with a slightly earlier SN, and the RX background is very harsh and sharp sounding. We both came to Elecraft from a PRO II/III where the background in an A/B comparison is a soft swhoooooooooooosh.
>>
>> I'd like to check and see if it has the same mod, but I've slept since then and cannot remember what the mod was called, or how to check for it. A tour of the mods page didn't kick my recaller into gear.
>>
>> A related wish: List the serial number when a mod goes into production.
>>
>> n unrelated wish: HAPPY 4th!
>>
>> 73, Mike NF4L
>>
>>
>>
>> ______________________________________________________________
>> 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

Don Wilhelm-4

Re: Noisy RX redux

In reply to this post by Mike Reublin

Mike,

The most important part of determining which AGC settings will work for
you is in the statement that you should not be listening for the noise
neither with a signal active, nor with no signal - you want to listen
for the K3 audio response between breaks in the received signal.

To a certain extent, the AGC settings that you would prefer depend on
your operating preferences. A CW operator who is doing contesting or
DXing would like to have a difference between strong signals and weak
ones, while a ragchewer would probably prefer to have most of the
signals at the same audio level.

73,
Don W3FPR

On 7/4/2013 6:38 PM, Mike Reublin wrote:

> Thanks, Don.
>
> I played around with the AGC settings as you describe, and I can't say I found settings that made a difference. But I do have a tin ear.
>
> You don't happen to remember where the DSP board mod is on the website, do you?
>
> Mike
>
> On Jul 4, 2013, at 5:47 PM, Mike Reublin <[hidden email]> wrote:
>
>> Shortly after I got K3 3935 in Sept. of '09, the furor over noisy RX kinda peaked, and the result was a board swap.
>>
>> A friend just bought a used K3 with a slightly earlier SN, and the RX background is very harsh and sharp sounding. We both came to Elecraft from a PRO II/III where the background in an A/B comparison is a soft swhoooooooooooosh.
>>
>> I'd like to check and see if it has the same mod, but I've slept since then and cannot remember what the mod was called, or how to check for it. A tour of the mods page didn't kick my recaller into gear.
>>
>> A related wish: List the serial number when a mod goes into production.
>>
>> n unrelated wish: HAPPY 4th!
>>
>> 73, Mike NF4L
>>
>>
>>
>> ______________________________________________________________
>> 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
>

Bill Clarke

Re: Noisy RX redux

In reply to this post by Mike Reublin

You may be interested in my solution: http://www.w2blc.net/K3.htm

I am mostly an armchair copy inhabitant of 75 and 40 meters, hence the
setup that I use.

Bill W2BLC
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Mike K2MK

Re: Noisy RX redux

In reply to this post by Mike Reublin

Hi Mike,

For those wondering what Mike found. There are two ways to go. A complete DSP board swap or a DSP board modification.

K3DSPUPGD for $109.95 (this is the board swap)
or
K3DSPLPF for $39.95 (this is the board mod)

Both items can be found here:
http://www.elecraft.com/order_form_parts.htm

Serial numbers might not be the best clue for those buying a previously owned radio. The previous owner might have already made the improvement.

73,
Mike K2MK

Mike Reublin wrote

I found the mod.

On Jul 4, 2013, at 6:38 PM, Mike Reublin <[hidden email]> wrote:

> On Jul 4, 2013, at 5:47 PM, Mike Reublin <[hidden email]> wrote:
>
>> Shortly after I got K3 3935 in Sept. of '09, the furor over noisy RX kinda peaked, and the result was a board swap.
>>
>> A friend just bought a used K3 with a slightly earlier SN, and the RX background is very harsh and sharp sounding. We both came to Elecraft from a PRO II/III where the background in an A/B comparison is a soft swhoooooooooooosh.
>>
>> I'd like to check and see if it has the same mod, but I've slept since then and cannot remember what the mod was called, or how to check for it. A tour of the mods page didn't kick my recaller into gear.
>>
>> A related wish: List the serial number when a mod goes into production.
>>
>> n unrelated wish: HAPPY 4th!
>>
>> 73, Mike NF4L