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Phil Hystad-3

K2 Kit Questions

Gang,

So, I am thinking that another kit is in my future. I have a K3 and a KX1 and I am thinking about the K2. I would be using it for CW and QRP or 2*QRP only. So, I wouldn't plan on getting the SSB option and I am not planning on the 100 watt PA or the ATU.

But, I do have questions about filters (remember, CW usage only).

1. Question: is the radio a completely analog radio (no DSP) if you DO NOT buy the DSP filter option?

2. Question: is the DSP filter worth the money?

3. Question: is the Audio filter useful? Is the Audio filter still useful if I buy the DSP filter?

Any other comments and suggestions are definitely accepted.

73, phil, K7PEH

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Jim Wiley-2

Re: K2 Kit Questions

Replies in-line

- Jim, KL7CC

Phil Hystad wrote:
> Gang,
>
> So, I am thinking that another kit is in my future. I have a K3 and a KX1 and I am thinking about the K2. I would be using it for CW and QRP or 2*QRP only. So, I wouldn't plan on getting the SSB option and I am not planning on the 100 watt PA or the ATU.
>
> But, I do have questions about filters (remember, CW usage only).
>
> 1. Question: is the radio a completely analog radio (no DSP) if you DO NOT buy the DSP filter option?
>

Yes, if you do not purchase the DSP option. A substantial amount of
"digital" is still used, but not directly in the signal path. The
digital stuff is used to control the rig, set and operate the VFO,
change bands, communicate between options, etc.
> 2. Question: is the DSP filter worth the money?
>

This is a subjective issue. Some people like the DSP (I do), others
prefer the simplicity of the audio filter (KAF2). I would recommend one
or the other, but the rig runs fine without them. Depends on your
operating style. For occasional use, the built in variable bandwidth
filter may be enough. I really like the combination of the variable
filter and DSP working together.
> 3. Question: is the Audio filter useful? Is the Audio filter still useful if I buy the DSP filter?
>

See above. Keep in mind that this is a choice of one or the other, not
both. The K2 cannot accept both units at once.
> Any other comments and suggestions are definitely accepted.
>

Buy the KAT2 internal tuner. You won't be sorry. It is astounding in
it's ability to match pretty much anything, and will be very helpful if
you decide to try "out in the field" operating with makeshift antennas.

- Jim,m KL7CC

> 73, phil, K7PEH
>
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>

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Johnny Siu

K2 Kit Questions

In reply to this post by Phil Hystad-3

Hello Phil,

My answers to your questions would be:

1. Question: is the radio a completely analog radio (no DSP) if you DO NOT buy
the DSP filter option?

Yes, completely analog. Even the KDSP2 is the audio stage.

2. Question: is the DSP filter worth the money?

Personally I don't think so, the artifact is annoying and no way comparable to
K3. IMHO, it is just a primitive DSP as at today technology.

3. Question: is the Audio filter useful? Is the Audio filter still useful if
I buy the DSP filter?

Yes, you can get KAF2 audio filter cheaply in the second hand market because
some elecrafters would like to dispose of theirs when they get the KDSP2. For a
price of about USD45 in the second hand market, you can get an audio filter +
internal clock, very value for money. Only either KDSP2 or KAF2 can be
installed but not both.

73

Johnny VR2XMC

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Don Wilhelm-4

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

Phil,

The K2 RF stages are all analog. Any digital signals are for control
purposes. The VFO is a PLL/VCO implementation.

You will get varied opinions about the KDSP2 vs. the KAF2 for CW use.
Some like the DSP, others prefer the KAF2, while others advocate that
the variable width IF filter is sufficient. I am in the latter category
- I have the KAF2 in mine but seldom use it. Since the KDSP2 and the
KAF2 occupy the same physical space inside the K2, only one can be
present at a time.

If you are considering the use of digital modes, you will want to
install the KSB2 even though you do not intend to operate SSB.

If you are contemplating portable operation, you will want to include
the KAT2 internal tuner. If you have any desires to connect the K2 to a
rig control computer application (logger or something more exotic), you
will want the KIO2.

73,
Don W3FPR

On 2/7/2011 7:51 PM, Phil Hystad wrote:

> Gang,
>
> So, I am thinking that another kit is in my future. I have a K3 and a KX1 and I am thinking about the K2. I would be using it for CW and QRP or 2*QRP only. So, I wouldn't plan on getting the SSB option and I am not planning on the 100 watt PA or the ATU.
>
> But, I do have questions about filters (remember, CW usage only).
>
> 1. Question: is the radio a completely analog radio (no DSP) if you DO NOT buy the DSP filter option?
>
> 2. Question: is the DSP filter worth the money?
>
> 3. Question: is the Audio filter useful? Is the Audio filter still useful if I buy the DSP filter?
>
> Any other comments and suggestions are definitely accepted.
>
> 73, phil, K7PEH
>
> ______________________________________________________________
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>

g3ymc

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

On 7 Feb 2011 at 16:51, Phil Hystad wrote:

> 2. Question: is the DSP filter worth the money?
>
> 3. Question: is the Audio filter useful? Is the Audio filter still
> useful if I buy the DSP filter?
>

I am an exclusively CW op. I have the KAF2 fitted but it is never used.
It may be useful for SSB ops, but for CW the CW 400Hz filter does
everything you want - I have FL4 set to 200Hz but even that never gets
used.

I would endorse what others say, get the KAT2. If you intend to use it
for contesting then the KIO2 is essential for rig control. The KAT160
is also very handy for giving you the two antenna option even if you
don't use top band.

73 Dave G3YMC

http://www.davesergeant.com

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Johnny Siu

K2 Kit Questions

Yes, KAT2 is a good option because it can tune almost anything. I use KAT2 to
tune a 40 ft random wire and PTT at any time I like. K160RX is not expensive.
If you order KAT2 + K160RX at the same time, you will save some shipping costs.

cheers,

Johnny VR2XMC

________________________________
寄件人﹕ Dave Sergeant <[hidden email]>
收件人﹕ Elecraft Reflector <[hidden email]>
傳送日期﹕ 2011/2/8 (二) 2:46:28 PM
主題： Re: [Elecraft] K2 Kit Questions

On 7 Feb 2011 at 16:51, Phil Hystad wrote:

> 2. Question: is the DSP filter worth the money?
>
> 3. Question: is the Audio filter useful? Is the Audio filter still
> useful if I buy the DSP filter?
>

I am an exclusively CW op. I have the KAF2 fitted but it is never used.
It may be useful for SSB ops, but for CW the CW 400Hz filter does
everything you want - I have FL4 set to 200Hz but even that never gets
used.

I would endorse what others say, get the KAT2. If you intend to use it
for contesting then the KIO2 is essential for rig control. The KAT160
is also very handy for giving you the two antenna option even if you
don't use top band.

73 Dave G3YMC

http://www.davesergeant.com

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Mike Harris

Re: K2 Kit Questions

In reply to this post by Jim Wiley-2

Hi Phil,

I would agree with those who prefer the KAF2 over the KDSP2, I have
them both and have reinstalled the KAF2. All analogue antenna to
ear.

One or the other is a must have. I noticed a huge improvement in
the reduction of high frequency hiss from the audio stage with the
KAF2 installed, it has a low pass filter stage which is always
inline.

Regards,

Mike VP8NO
K2 #1400
K3 #345

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jeff martin-6

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

Phil,
I use the KDSP2 and generally like it very much. I set one of the DSP CW filter settings to 50Hz bandwidth and increase the filter gain. Seems to help for pulling weak ones out of the band noise under some conditions. I don't find the sound of signals processed through the DSP filters a problem. The noise reduction works, but requires experimentation with the settings to achieve results. I can understand why some find the NR sound to be a bit unusual but it is no worse than the audio DSP on my TS480.

Jeff
N7KRT

--- On Mon, 2/7/11, Phil Hystad <[hidden email]> wrote:

> From: Phil Hystad <[hidden email]>
> Subject: [Elecraft] K2 Kit Questions
> To: "Elecraft Reflector" <[hidden email]>
> Date: Monday, February 7, 2011, 4:51 PM
> Gang,
>
> So, I am thinking that another kit is in my future. I
> have a K3 and a KX1 and I am thinking about the K2. I
> would be using it for CW and QRP or 2*QRP only. So, I
> wouldn't plan on getting the SSB option and I am not
> planning on the 100 watt PA or the ATU.
>
> But, I do have questions about filters (remember, CW usage
> only).
>
> 1. Question: is the radio a completely analog
> radio (no DSP) if you DO NOT buy the DSP filter option?
>
> 2. Question: is the DSP filter worth the
> money?
>
> 3. Question: is the Audio filter useful?
> Is the Audio filter still useful if I buy the DSP filter?
>
> Any other comments and suggestions are definitely
> accepted.
>
> 73, phil, K7PEH
>
> ______________________________________________________________
> 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
>

Phil Hystad-3

Re: K2 Kit Questions

Gang,

Thanks for all the comments in answer to my question about the K2 Kit. As usual, this group is a real benefit to learning all about the Elecraft stuff.

My K2 plans look like this:

1. Basic K2 Kit, QRP only.
2. Internal ATU.
3. KAF2 Audio Filter.
4. KIO2.

I am in no rush to get the K2 as right now I don't have the time to put one together. But, it will be a Spring or Summer project.

A possible follow-up question --- one recommendation I received (indirectly out of band from this group) was that the SSB option was useful for the wider filter even if you do not plan to do SSB. I have yet to read through all of the K2 manual (my next project) so I don't know much about the filters on the K2 so far.

73, phil, K7PEH
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Don Wilhelm-4

Re: K2 Kit Questions

Phil,

For me, that is an awfully wide filter for CW. I normally tune CW with
a filter set to 700 Hz. a 2.4kHz wide filter hears a lot more of the
band - too much for me.

OTOH, there are some operators who like to use a wide filter to hear a
lot of what is going on around their frequency. If you are in that
class and have a good "filter between the ears", then by all means use
it that way.

I might point out one other disadvantage of using the wide filter for
CW. If a strong signal is on the band say 1500 Hz away from the weaker
signal you are trying to copy, your mind may be able to easily separate
the two, but that strong signal is also activating the AGC and all
signals in the passband will be reduced in strength because of it. That
is why narrow "roofing filters" are offered for the K3 - even though the
DSP can create a narrow filter, the hardware AGC is still responding to
the strongest signal in the passband. The same argument applies to the K2.

73,
Don W3FPR

On 2/8/2011 10:39 AM, Phil Hystad wrote:
> A possible follow-up question --- one recommendation I received (indirectly out of band from this group) was that the SSB option was useful for the wider filter even if you do not plan to do SSB. I have yet to read through all of the K2 manual (my next project) so I don't know much about the filters on the K2 so far.
>
> 73, phil, K7PEH
>
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Jim Wiley-2

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

Phil -

I would definitely recommend considering the SSB option. As another
person mentioned, you will need it if you are contemplating using one of
the data modes. There is even the (remote) possibility you might want
to use SSB at least occasionally <grin>.

However, the beauty of the K2 is that you can add this option, and the
K160 module, which I predict you will eventually want too, at some
undefined later date. Therefore, you don't have to plop down all the
cash at once, and building some modules later will help with the
inevitable "why am I not soldering something today?" feeling that will
come upon you once the K2 has been finished for a while.

Good luck with the K2.

- Jim,. KL7CC

Phil Hystad wrote:
>
> Thanks for all the comments in answer to my question about the K2 Kit. <snip>
>
A possible follow-up question --- one recommendation I received (indirectly out of band from this group) was that the SSB option was useful for the wider filter even if you do not plan to do SSB.

<snip>
> 73, phil, K7PEH
>

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Paul Huff-3

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

Hi Phil,

I am exclusively a QRP CW guy. I put the KAF2 audio filter in my K2. It works
great but I have only used it a couple of times. (I've had it for about 7 or 8
months.) The regular audio filter settings on the stock radio do a very good
job for casual operating. The K2 is a lot of fun to build and operate. You
will enjoy it.

73,
Paul - N8XMS

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Phil Hystad-3

Re: K2 Kit Questions

In reply to this post by Don Wilhelm-4

Don,

I still use a fairly wide filter (1 KHz to 1.5 KHz) on my K3 when I am hunting for CW signals or listening to broad activity. I have the P3 also that helps out a bit but I usually do not close down my filter until I establish contact and have narrowed down to the other operator. Then I will typically narrow down to about 350 Hz unless there is heavy activity causing QRM and then I will go even further.

If I do my hunt activity with a narrow filter I sometimes go over stations without even hearing them at all. Although the P3 does help here, often there are stations that do not really register that high on the P3 to be easily visible with just a glance.

I agree that 2.4 KHz is too wide for CW but then I am not that familiar with the filters that are available and I so I am not sure whether the SSB is necessary or not. I only pointed out that it was something that I had heard someone else doing.

phil, K7PEH

On Feb 8, 2011, at 8:44 AM, Don Wilhelm wrote:

> Phil,
>
> For me, that is an awfully wide filter for CW. I normally tune CW with a filter set to 700 Hz. a 2.4kHz wide filter hears a lot more of the band - too much for me.
>
> OTOH, there are some operators who like to use a wide filter to hear a lot of what is going on around their frequency. If you are in that class and have a good "filter between the ears", then by all means use it that way.
>
> I might point out one other disadvantage of using the wide filter for CW. If a strong signal is on the band say 1500 Hz away from the weaker signal you are trying to copy, your mind may be able to easily separate the two, but that strong signal is also activating the AGC and all signals in the passband will be reduced in strength because of it. That is why narrow "roofing filters" are offered for the K3 - even though the DSP can create a narrow filter, the hardware AGC is still responding to the strongest signal in the passband. The same argument applies to the K2.
>
> 73,
> Don W3FPR
>
> On 2/8/2011 10:39 AM, Phil Hystad wrote:
>> A possible follow-up question --- one recommendation I received (indirectly out of band from this group) was that the SSB option was useful for the wider filter even if you do not plan to do SSB. I have yet to read through all of the K2 manual (my next project) so I don't know much about the filters on the K2 so far.
>>
>> 73, phil, K7PEH
>>

Don Wilhelm-4

Re: K2 Kit Questions

Phil,

The K2 variable filter can be set for any width that you desire It is a
5 crystal Cohn filter whose design width is about 400 Hz. The CW filter
width defaults are 1.50 kHz, 700 Hz, 400 Hz and 100 Hz, but there is no
reason you have to stay with the defaults. There are 4 CW filter widths
that can be chosen. There are also 4 widths for the SSB filter set and
4 for the RTTY filter set.

The variable filter is pretty flat out to about 1.6 or 1.7 kHz, but then
it begins to get a bit "ragged" - still it is quite usable for SSB
reception, but I would not want to see a SSB signal transmitted through
it - that is where the 2.4 kHz SSB filter on the KSB2 board comes in.
It is a fixed width and has 7 crystals.

73,
Don W3FPR

On 2/8/2011 4:48 PM, Phil Hystad wrote:
> Don,
>
> I still use a fairly wide filter (1 KHz to 1.5 KHz) on my K3 when I am hunting for CW signals or listening to broad activity. I have the P3 also that helps out a bit but I usually do not close down my filter until I establish contact and have narrowed down to the other operator. Then I will typically narrow down to about 350 Hz unless there is heavy activity causing QRM and then I will go even further.
>
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AC7AC

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

CONTENTS DELETED

The author has deleted this message.

Bill Coleman-2

Re: K2 Kit Questions

In reply to this post by Phil Hystad-3

Bill Coleman-2

Re: K2 Kit Questions

On Feb 27, 2011, at 3:32 PM, Bill Coleman wrote:

>
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Curious. Because I sent:

On Feb 7, 2011, at 7:51 PM, Phil Hystad wrote:

> 1. Question: is the radio a completely analog radio (no DSP) if you DO NOT buy the DSP filter option?

Yes.

> 2. Question: is the DSP filter worth the money?

For SSB, I would say most definitely YES.

> 3. Question: is the Audio filter useful? Is the Audio filter still useful if I buy the DSP filter?

I did not find the KAF2 useful. The KDSP2 fits in the same place. You can have one or the other, but not both.

Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email]
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901

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Curt Milton

Re: K2 Kit Questions

Phil

Others opinions may vary, but here is my experience - a K2 works well without
DSP.

Yes you already likely heard a base K2 is all analog. But note that is has this
feature - the xtal filter bandwidth is programmable. I literally have mine set
up for 700, 400, 250 and 100 Hz bandwidth. After getting these selectable
filters well centered - it acts a lot like using a DSP filter - and I find it
provides enough settings for CW. The filter shapes are not quite as sharp as
DSP, but still pretty good. Also with no DSP, the audio is pleasant to listen
to. In my opinion, the rig works great with no DSP.

I also have the SSB filters set to vary from 1.6 kHz upward. They also work
pretty well. Here a DSP filter could help with adjacent frequency interference
by being sharper.

If you are planning on all CW, or even mostly CW, I suggest you can do well
without the DSP. For many years my K2 was only equipped with 160m and SSB
options.

I do use a NESCAF external audio filter for pulling weak signals out on 160 and
80m. It has a potentiometer for BW adjustment - which you might prefer over the
internal fixed settings.

But I have this feeling you might be thrilled enough with using your K3 at QRP
levels, so you'll have to weigh do you really need this other rig in the shack,
or for travel when you have a KX1. You could diversify your 'build' portfolio
by doing something homebrew and/or another QRP project (hint check Az Scorpions
and FourState for ideas).

73 Curt

Gang, So, I am thinking that another kit is in my future. I have a K3 and a
KX1 and I am thinking about the K2. I would be using it for CW and QRP or 2*QRP
only. So, I wouldn't plan on getting the SSB option and I am not planning on
the 100 watt PA or the ATU. But, I do have questions about filters (remember,
CW usage only). 1. Question: is the radio a completely analog radio (no DSP)
if you DO NOT buy the DSP filter option? 2. Question: is the DSP filter worth
the money? 3. Question: is the Audio filter useful? Is the Audio filter
still useful if I buy the DSP filter? Any other comments and suggestions are
definitely accepted. 73, phil, K7PEH

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K1FFX

Re: K2 Kit Questions

I can share my recent experience in the ARRL CW DX contest.

I have a K2/100 with no additional filtering (i.e., no KAF2 or KDSP2). I had
the variable bandwidth crystal filter set to 1000 Hz, 500 Hz, 300 Hz, and 150 Hz.
I ran most of the contest set to 150 Hz.

There were a few times when I felt like additional filtering would have been
a "nice to have". There were no times when I felt like it was a "gotta have".

And that was also my experience in the CQ WW last November (running 10
watts pre-KPA100!).

I'm probably going to build the AF1 external audio filter later this year. I'm
sure it will be handy, but I'd do it mostly for the pleasure of building another
mini-module!

Cheers -

Bruce

Bruce Rosen
K1FFX
K2/100 6982 KSB2 KAT100-1 KAF2 KIO2