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K3 cw rise time

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Tony - KM0O

K3 cw rise time

Hello,

This subject came up in a recent conversation, and I had to admit that I do
not know the cw rise time of my K3. It's s/n 444, and does not have the cw
rise time mod that elecraft sells. The firmware is the current version.

I read somewhere that the rise time was decreased in a previous firmware
issue, but I don't know if that's true.

It was originally 8ms, I think, which is unnecessarily long.

Can anyone help?

73,
Tony KM0O

--
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Jim Brown-10

Re: K3 cw rise time

On 4/12/2021 11:34 AM, Tony - KM0O wrote:
> I read somewhere that the rise time was decreased in a previous firmware
> issue, but I don't know if that's true.

Beginning with the earliest K3s, all Elecraft rigs use carefully shaped
keying to minimize clicks while maximizing readability. Wayne describes
it as a "sigmoidal" shape, describing the math function he used. It's
keying bandwidth as compared to other rigs can been seen here.

http://k9yc.com/TXNoise.pdf (ARRL Lab data)

and here

http://k9yc.com/P3_Spectrum_Measurements.pdf (My data)

73, Jim K9YC
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John Simmons

Re: K3 cw rise time

I still think Drake 4-line had the best-sounding CW note. Has anyone
measured it?

-de John NI0K

Jim Brown wrote on 4/12/2021 1:47 PM:

> On 4/12/2021 11:34 AM, Tony - KM0O wrote:
>> I read somewhere that the rise time was decreased in a previous firmware
>> issue, but I don't know if that's true.
>
> Beginning with the earliest K3s, all Elecraft rigs use carefully
> shaped keying to minimize clicks while maximizing readability. Wayne
> describes it as a "sigmoidal" shape, describing the math function he
> used. It's keying bandwidth as compared to other rigs can been seen here.
>
> http://k9yc.com/TXNoise.pdf (ARRL Lab data)
>
> and here
>
> http://k9yc.com/P3_Spectrum_Measurements.pdf (My data)
>
> 73, Jim K9YC
> ______________________________________________________________
> 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]

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Larry (K8UT)

Re: K3 cw rise time

In reply to this post by Tony - KM0O

Tony,

>...8ms, I think, which is unnecessarily long.

Just yesterday, Rob Sherwood gave a Zoom presentation to the local
SLAARC titled "Transmitter Spectral Purity." He spoke at length about
the evils of fast rise times and cited the optimal rise time as between
6 and 8 ms.
The Elecraft K3 line was described as one of the best behaved CW rigs,
with a rise time of 6ms
Yaesu rigs were denounced for being user-configurable from 1ms to 8ms,
giving owners an opportunity to litter the bands with shorter times and
key clicks.
Slightly over 60 minutes long: https://youtu.be/EKCKkV5Nowo

-larry (K8UT)

------ Original Message ------
From: "Tony - KM0O" <[hidden email]>
To: [hidden email]
Sent: 2021-04-12 14:34:16
Subject: [Elecraft] K3 cw rise time

>Hello,
>
>This subject came up in a recent conversation, and I had to admit that I do
>not know the cw rise time of my K3. It's s/n 444, and does not have the cw
>rise time mod that elecraft sells. The firmware is the current version.
>
>I read somewhere that the rise time was decreased in a previous firmware
>issue, but I don't know if that's true.
>
>It was originally 8ms, I think, which is unnecessarily long.
>
>Can anyone help?
>
>73,
>Tony KM0O
>
>
>
>
>--
>Sent from: http://elecraft.365791.n2.nabble.com/
>______________________________________________________________
>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]

Carl Clawson-3

Re: K3 cw rise time

In reply to this post by Tony - KM0O

Hi Tony. According to the K3 mod page, this was introduced at about s/n 280
so you're good to go.

You made me wonder why I hadn't heard of it! I have K3 #486 and I've done
almost every mod that they have come up with..

73, Carl WS7L

On Mon, Apr 12, 2021 at 11:35 AM Tony - KM0O <[hidden email]> wrote:

> Hello,
>
> This subject came up in a recent conversation, and I had to admit that I do
> not know the cw rise time of my K3. It's s/n 444, and does not have the cw
> rise time mod that elecraft sells. The firmware is the current version.
>
> I read somewhere that the rise time was decreased in a previous firmware
> issue, but I don't know if that's true.
>
> It was originally 8ms, I think, which is unnecessarily long.
>
> Can anyone help?
>
> 73,
> Tony KM0O
>
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/
> ______________________________________________________________
> 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]
>