K2 Filter question

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K2 Filter question

Mike Smith VE9AA
Hello from NB,

 

It's Mike,  VE9AA...I own a K3 but almost never use it (only for FD and
portable ops -I've used it twice in my year of ownership)

 

I am thinking about maybe buying a used K2/10 with many options,(no DSP
board I don't think) but as I don't know a thing about the K2 (and after
reviewing the Elecraft website) I had this hopefully simple question. (I
have not yet contacted the seller)

 

Are there optional CW filters still available for the K2 or does it come
with them all built in ?  

 

I do mostly CW so was looking at doing most of my operating with a 200-300Hz
filter.(and perhaps with a 1.8kHz SSB filter when I am on phone)

 

I apologize if the answer is overly obvious !

 

Thanks much,

 

dit dit Mike VE9AA

 

Mike, Coreen & Corey

Keswick Ridge, NB

 

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Re: K2 Filter question

Don Wilhelm
Mike,

The K2 has a built-in 5 pole filter on the RF board that you can set to
variable widths using the CAL FIL menu - you must have the internal
counter probe to change the filter settings.
There are 4 filter settings for each mode.

These are not "roofing filters" as used in the K3, but IF crystal
filters.  The filter type in the base K2 is of a Cohn design and the
width can be changed as I stated above.  Its design width is about 500Hz
and gives a nice passband from about 1.5kHz down to about 200Hz.
It can be widened out to SSB listening levels, but the passband becomes
quite ragged at those wider widths.  It is however suitable for SSB
listening.  The filter on the KSB2 option board has a nice flat passband.

The KSB2 option (for SSB) has a fixed width 7 pole filter.  The early
filters were 2.1kHz width, but more recent filters are 2.4kHz.
Elecraft has a capacitor kit which will allow you to change the filter
width.

The crystals used in the K2 filter were upgraded to better speced
crystals at SN 2560.  I would recommend that K2s below that SN be
upgraded with the new crystals.  Elecraft sells a kit of matched
crystals at a very reasonable price a set of 7 for the base K2 or a set
of 14 for both the base K2 and the KSB2 option.

73,
Don W3FPR

On 1/8/2017 11:10 AM, Mike Smith VE9AA wrote:

> It's Mike,  VE9AA...I own a K3 but almost never use it (only for FD and
> portable ops -I've used it twice in my year of ownership)
>
> I am thinking about maybe buying a used K2/10 with many options,(no DSP
> board I don't think) but as I don't know a thing about the K2 (and after
> reviewing the Elecraft website) I had this hopefully simple question. (I
> have not yet contacted the seller)
>
>
>
> Are there optional CW filters still available for the K2 or does it come
> with them all built in ?
>
>
>
> I do mostly CW so was looking at doing most of my operating with a 200-300Hz
> filter.(and perhaps with a 1.8kHz SSB filter when I am on phone)
>
>
>
> I apologize if the answer is overly obvious !
>
>
>
> Thanks much,
>
>
>
> dit dit Mike VE9AA
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
> ______________________________________________________________
> 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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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Re: K2 Filter question

Mike Smith VE9AA
Wonderful !  A better answer I could not imagine.
Thanks Don.  Most excellent information.

73, Mike VE9AA

Mike, Coreen & Corey
Keswick Ridge, NB


-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: January 8, 2017 12:45 PM
To: Mike Smith VE9AA; [hidden email]
Subject: Re: [Elecraft] K2 Filter question

Mike,

The K2 has a built-in 5 pole filter on the RF board that you can set to
variable widths using the CAL FIL menu - you must have the internal counter
probe to change the filter settings.
There are 4 filter settings for each mode.

These are not "roofing filters" as used in the K3, but IF crystal filters.
The filter type in the base K2 is of a Cohn design and the width can be
changed as I stated above.  Its design width is about 500Hz and gives a nice
passband from about 1.5kHz down to about 200Hz.
It can be widened out to SSB listening levels, but the passband becomes
quite ragged at those wider widths.  It is however suitable for SSB
listening.  The filter on the KSB2 option board has a nice flat passband.

The KSB2 option (for SSB) has a fixed width 7 pole filter.  The early
filters were 2.1kHz width, but more recent filters are 2.4kHz.
Elecraft has a capacitor kit which will allow you to change the filter
width.

The crystals used in the K2 filter were upgraded to better speced crystals
at SN 2560.  I would recommend that K2s below that SN be upgraded with the
new crystals.  Elecraft sells a kit of matched crystals at a very reasonable
price a set of 7 for the base K2 or a set of 14 for both the base K2 and the
KSB2 option.

73,
Don W3FPR

On 1/8/2017 11:10 AM, Mike Smith VE9AA wrote:

> It's Mike,  VE9AA...I own a K3 but almost never use it (only for FD and
> portable ops -I've used it twice in my year of ownership)
>
> I am thinking about maybe buying a used K2/10 with many options,(no DSP
> board I don't think) but as I don't know a thing about the K2 (and after
> reviewing the Elecraft website) I had this hopefully simple question. (I
> have not yet contacted the seller)
>
>
>
> Are there optional CW filters still available for the K2 or does it come
> with them all built in ?
>
>
>
> I do mostly CW so was looking at doing most of my operating with a
200-300Hz

> filter.(and perhaps with a 1.8kHz SSB filter when I am on phone)
>
>
>
> I apologize if the answer is overly obvious !
>
>
>
> Thanks much,
>
>
>
> dit dit Mike VE9AA
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
> ______________________________________________________________
> 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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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Re: K2 Filter question

RobertG
In reply to this post by Mike Smith VE9AA
Mike...

The K2 does not have individual filters like the K3. It has a set of
serial crystals in a lattice filter arrangement [sic] that can be
voltage biased to yield various effective filter widths from very narrow
to broad. There are provisions to select three/four  pre-programed
filter widths per mode [not quite sure of this one]. The various widths
are set up in the filter calibration mode of the K2. W3FPR Don Wilheim's
site has all sorts of information on general principles as well as
step-by-step instructions for setting the filter widths in the K2. An
auxiliary program called "Spectogram" is used to portray the filter
widths on the computer screen so that one can see the shape/bandwidth of
the filter during setup. In my experience, the filtering system in the
K2 is quite effective. Others will no doubt add to this limited
description of the K2 filtering method and results.

...robert KE2WY

On 01/08/2017 16:10, Mike Smith VE9AA wrote:

> Hello from NB,
>
>
>
> It's Mike,  VE9AA...I own a K3 but almost never use it (only for FD and
> portable ops -I've used it twice in my year of ownership)
>
>
>
> I am thinking about maybe buying a used K2/10 with many options,(no DSP
> board I don't think) but as I don't know a thing about the K2 (and after
> reviewing the Elecraft website) I had this hopefully simple question. (I
> have not yet contacted the seller)
>
>
>
> Are there optional CW filters still available for the K2 or does it come
> with them all built in ?
>
>
>
> I do mostly CW so was looking at doing most of my operating with a 200-300Hz
> filter.(and perhaps with a 1.8kHz SSB filter when I am on phone)
>
>
>
> I apologize if the answer is overly obvious !
>
>
>
> Thanks much,
>
>
>
> dit dit Mike VE9AA
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
> ______________________________________________________________
> 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]
>

--
Robert G Strickland, PhD ABPH - KE2WY
[hidden email]
Syracuse, New York, USA
______________________________________________________________
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Re: K2 Filter question

Michael Babineau-2
In reply to this post by Mike Smith VE9AA
It is also worth mentioning that the KAF2 (audio filter and real-time clock) is  a good addition for CW reception.

IMHO it does help a lot when copying weak signals and also having the real-time clock is useful.

http://www.elecraft.com/kaf2.htm

Michael VE3WMB (K2 #5995)


>From: Don Wilhelm <[hidden email] <mailto:[hidden email]>>
>Subject: Re: [Elecraft] K2 Filter question
>Date: January 8, 2017 at 11:45:09 AM GMT-5
>To: Mike Smith VE9AA <[hidden email] <mailto:[hidden email]>>, [hidden email] <mailto:[hidden email]>
>Reply-To: [hidden email] <mailto:[hidden email]>


>Mike,

>The K2 has a built-in 5 pole filter on the RF board that you can set to variable widths using the CAL FIL menu - you must have the internal counter probe to change the filter settings.
>There are 4 filter settings for each mode.

>These are not "roofing filters" as used in the K3, but IF crystal filters.  The filter type in the base K2 is of a Cohn design and the width can be changed as I stated above.  Its design width is about 500Hz >and gives a nice passband from about 1.5kHz down to about 200Hz.
>It can be widened out to SSB listening levels, but the passband becomes quite ragged at those wider widths.  It is however suitable for SSB listening.  The filter on the KSB2 option board has a nice flat >passband.

>The KSB2 option (for SSB) has a fixed width 7 pole filter.  The early filters were 2.1kHz width, but more recent filters are 2.4kHz.
>Elecraft has a capacitor kit which will allow you to change the filter width.

>The crystals used in the K2 filter were upgraded to better speced crystals at SN 2560.  I would recommend that K2s below that SN be upgraded with the new crystals.  Elecraft sells a kit of matched >crystals at a very reasonable price a set of 7 for the base K2 or a set of 14 for both the base K2 and the KSB2 option.

>73,
>Don W3FPR
______________________________________________________________
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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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