Date   

Re: Other filters in the K3

bill_w4zv <w0zv@...>
 

--- In Elecraft_K3@..., "ab2tc" <ab2tc@...> wrote:

Don't forget that these lower bandwidth CW filters are all standard
DSP functions with the K3. You don't have to spend another cent to
obtain them. Only under the most extreme conditions will the optional
lower bandwidth IF filters make a difference, or at least that's what
we all expect.
Hans, Knut is absolutely correct. You are thinking the 1000 and 400
are typical final bandwidth filters as in the FT-1000D. That is
definitely NOT the case with the K3. The DSP will provide filters
from 50 Hz up to at least 6000 Hz in 50 Hz steps. The roofing filters
are there primarily to prevent adjacent S9+30 dB signals from causing
IMD products within the DSP stage.

Unless you plan to operate within about 1 kHz of S9+30 dB signals (as
in a contest or multi-transmitter environment), the standard 2.7 kHz
filter will be entirely adequate. Remember that even with Inrad's
roofing filter mod for the FT-1000D, that filter is only ~5 kHz
bandwidth, so the stock 2.7 kHz in K3 will already be half of the
1000D + Inrad!

73, Bill


Re: [Elecraft_K3] Re: Other filters in the K3

Frank LaFranco <flafranco@...>
 

Woops!
Very sorry for the incorrect information on the credit amount when swapping the 2.7 kHz 5 pole filter for the 2.8 kHz 8 pole filter. I'll double check my figures in future posts.

Thanks Eric,
Frank - W6NEK

----- Original Message -----
From: Eric C. Swartz
To: Elecraft_K3@...
Sent: Monday, September 24, 2007 11:51 AM
Subject: [Elecraft_K3] Re: Other filters in the K3


One correction - Frank is incorrect about the credit amount when
swapping the 2.7 kHz 5 pole filter for the 2.8 kHz 8 pole filter. The
credit is $30 off of the purchase price of the 8 pole filter.

Also, this credit may only be applied at time of original purchase.

73, Eric WA6HHQ


Re: Other filters in the K3

Eric Swartz - WA6HHQ, Elecraft
 

One correction - Frank is incorrect about the credit amount when
swapping the 2.7 kHz 5 pole filter for the 2.8 kHz 8 pole filter. The
credit is $30 off of the purchase price of the 8 pole filter.

Also, this credit may only be applied at time of original purchase.

73, Eric WA6HHQ


--- In Elecraft_K3@..., "Frank LaFranco" <flafranco@...>
wrote:
Buy the way, if you wanted to upgrade to the 8 pole 2.8 KHz filter,
Elecraft
will allow $79 dollars off the price of the upgrade at the time of K3
purchase.


Re: Other filters in the K3

Eric Swartz - WA6HHQ, Elecraft
 

Hi Bill,

Yes, we allow you to select which filter is used in TX for -each- mode
. We default to the 2.7 or 2.8 filter for SSB and CW TX, but you
certainly could TX through a narrower filter. The only limit will be
the narrower filter's impact on CW rise/fall times and possibly narrow
filter recovery from TX for fast break-in.

73, Eric

P.S. I may not reply to all posts here or on the other Elecraft lists
as I am focused on getting these guys out the door. :-)

--- In Elecraft_K3@..., "bill_w4zv" <w0zv@...> wrote:

Hi Eric,

--- In Elecraft_K3@..., "Eric C. Swartz"
<wa6hhq_lists@> wrote:

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.
I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).

I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.

73, Bill


Re: [Elecraft_K3] Re: Other filters in the K3

Doug Faunt N6TQS +1-510-655-8604
 

Since nothing is perfect, there may be artifacts outside the DSP
generated signal bandwidth that the narrower TX "roofing" filter would
attentuate even further. Since the 2.1kHz filter seems to be adequate
for most purposes, especially mine, I'd like to have that extra
filtering, all else being equal.

73, doug

From: "Frank LaFranco" <flafranco@...>
Date: Mon, 24 Sep 2007 10:00:44 -0700

Hi,
From what I understand, the K3 SSB final transmit bandwidth is determined by
the DSP settings. Therefore, I see no problem using a 2.8 KHz roofing
filter and transmitting a 300 Hz - 2.1 KHz SSB passband determined by the
DSP settings. As a matter of fact, I seem to remember Wayne saying that if
a 6 KHz roofing filter is used in SSB mode the DSP maximum bandwidth is
limited to 3.6 KHz. I guess what I'm trying to say is you don't need a 2.1
KHz roofing filter to limit SSB transmit bandwidth to 2.1 KHz. The final
bandwidth choice is derived by the DSP settings.

I guess a lot of questions will finally be answered once Elecraft starts
shipping K3's.

73,
Frank - W6NEK

----- Original Message -----
From: Doug Faunt N6TQS +1-510-655-8604
To: Elecraft_K3@...
Cc: Elecraft_K3@...
Sent: Monday, September 24, 2007 9:38 AM
Subject: Re: [Elecraft_K3] Re: Other filters in the K3


From: "ab2tc" <ab2tc@...>
Date: Mon, 24 Sep 2007 16:09:26 -0000

I would support an Elecraft policy of *not* selling any K3s without a
filter suitable for SSB operation. But I would have thought a 2.1kHz
filter would be sufficient for SSB transmission, narrowband but highly
spectrally efficient. 300-2400Hz audio is highly readable if not
exactly high fidelity.

Yes, in fact the K3 order form seems to allow a 2.1kHz filter, and my
recent interaction with Lisa (sales@...) seemed to result in
substituting the 2.1kHz filter for the 2.7kHz. This policy may have
changed, and my order may change, again.

The Collins rigs all used a 2.1kHz filter for SSB voice generation,
IIRC. And frankly, in my case, that filter will mostly be used for
generating signals for the "sound card modes".

73, doug







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Re: [Elecraft_K3] Re: Other filters in the K3

Frank LaFranco <flafranco@...>
 

Hi,
From what I understand, the K3 SSB final transmit bandwidth is determined by the DSP settings. Therefore, I see no problem using a 2.8 KHz roofing filter and transmitting a 300 Hz - 2.1 KHz SSB passband determined by the DSP settings. As a matter of fact, I seem to remember Wayne saying that if a 6 KHz roofing filter is used in SSB mode the DSP maximum bandwidth is limited to 3.6 KHz. I guess what I'm trying to say is you don't need a 2.1 KHz roofing filter to limit SSB transmit bandwidth to 2.1 KHz. The final bandwidth choice is derived by the DSP settings.

I guess a lot of questions will finally be answered once Elecraft starts shipping K3's.

73,
Frank - W6NEK

----- Original Message -----
From: Doug Faunt N6TQS +1-510-655-8604
To: Elecraft_K3@...
Cc: Elecraft_K3@...
Sent: Monday, September 24, 2007 9:38 AM
Subject: Re: [Elecraft_K3] Re: Other filters in the K3


From: "ab2tc" <ab2tc@...>
Date: Mon, 24 Sep 2007 16:09:26 -0000

I would support an Elecraft policy of *not* selling any K3s without a
filter suitable for SSB operation. But I would have thought a 2.1kHz
filter would be sufficient for SSB transmission, narrowband but highly
spectrally efficient. 300-2400Hz audio is highly readable if not
exactly high fidelity.

Yes, in fact the K3 order form seems to allow a 2.1kHz filter, and my
recent interaction with Lisa (sales@...) seemed to result in
substituting the 2.1kHz filter for the 2.7kHz. This policy may have
changed, and my order may change, again.

The Collins rigs all used a 2.1kHz filter for SSB voice generation,
IIRC. And frankly, in my case, that filter will mostly be used for
generating signals for the "sound card modes".

73, doug







Yahoo! Groups Links


Re: Other filters in the K3

ab2tc
 

Don't forget that these lower bandwidth CW filters are all standard
DSP functions with the K3. You don't have to spend another cent to
obtain them. Only under the most extreme conditions will the optional
lower bandwidth IF filters make a difference, or at least that's what
we all expect.

Knut - AB2TC

--- In Elecraft_K3@..., Hans Remeeus <hans@...> wrote:


Hello Bill,

2.7 kHz is a nice addition for monitoring the CW-frequencies. I
understand that this standard filter costs about $30.

1000 and 400 Hz still are my favorite CW-bandwidths. Perhaps the 250 Hz
filter later on.


73,
Hans Remeeus (PA1HR)
http://www.remeeus.eu
Communication is about people, the rest is technology.



bill_w4zv schreef:

I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).

I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.

73, Bill


Re: Other filters in the K3

Julian <julian@...>
 

--- In Elecraft_K3@..., "ab2tc" <ab2tc@...> wrote:

Hi,

I would support an Elecraft policy of *not* selling any K3s without a
filter suitable for SSB operation. But I would have thought a 2.1kHz
filter would be sufficient for SSB transmission, narrowband but highly
spectrally efficient. 300-2400Hz audio is highly readable if not
exactly high fidelity.

Knut - AB2TC
Whilst a narrower filter might make more sense for you, it is probably
a false economy, even if only that it may make the K3 less saleable
should you want to sell it at some time in the future, hard though
that is to imagine. :)

It's a bit like the folks around here who convert their garage into a
spare room. When they sell their house, not having a garage knocks
thousands off the value.

Julian, G4ILO


Re: [Elecraft_K3] Re: Other filters in the K3

Hans Remeeus <hans@...>
 

Hello Bill,

2.7 kHz is a nice addition for monitoring the CW-frequencies. I understand that this standard filter costs about $30.

1000 and 400 Hz still are my favorite CW-bandwidths. Perhaps the 250 Hz filter later on.


73,
Hans Remeeus (PA1HR)
http://www.remeeus.eu
Communication is about people, the rest is technology.



bill_w4zv schreef:

I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).
I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.
73, Bill


Re: [Elecraft_K3] Re: Other filters in the K3

Doug Faunt N6TQS +1-510-655-8604
 

From: "ab2tc" <ab2tc@...>
Date: Mon, 24 Sep 2007 16:09:26 -0000

I would support an Elecraft policy of *not* selling any K3s without a
filter suitable for SSB operation. But I would have thought a 2.1kHz
filter would be sufficient for SSB transmission, narrowband but highly
spectrally efficient. 300-2400Hz audio is highly readable if not
exactly high fidelity.

Yes, in fact the K3 order form seems to allow a 2.1kHz filter, and my
recent interaction with Lisa (sales@...) seemed to result in
substituting the 2.1kHz filter for the 2.7kHz. This policy may have
changed, and my order may change, again.

The Collins rigs all used a 2.1kHz filter for SSB voice generation,
IIRC. And frankly, in my case, that filter will mostly be used for
generating signals for the "sound card modes".

73, doug


Re: Other filters in the K3

ab2tc
 

Hi,

I would support an Elecraft policy of *not* selling any K3s without a
filter suitable for SSB operation. But I would have thought a 2.1kHz
filter would be sufficient for SSB transmission, narrowband but highly
spectrally efficient. 300-2400Hz audio is highly readable if not
exactly high fidelity.

Knut - AB2TC

--- In Elecraft_K3@..., "Frank LaFranco" <flafranco@...>
wrote:

The 5 pole 2.7 KHz filter is included with the base K3 at no additional
cost. Since the 2.7 KHz filter is included with all K3's I would be
reluctant to sell it even if I never used SSB. Somewhere down the
line a
prospective buyer would expect the 2.7 KHz filter to be there.

Buy the way, if you wanted to upgrade to the 8 pole 2.8 KHz filter,
Elecraft
will allow $79 dollars off the price of the upgrade at the time of K3
purchase.

73,
Frank - W6NEK


----- Original Message -----
From: bill_w4zv
To: Elecraft_K3@...
Sent: Monday, September 24, 2007 3:11 AM
Subject: [Elecraft_K3] Re: Other filters in the K3


Hi Eric,

--- In Elecraft_K3@..., "Eric C. Swartz"
<wa6hhq_lists@> wrote:

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.
I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).

I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.

73, Bill





Yahoo! Groups Links


Re: [Elecraft_K3] Re: Other filters in the K3

Frank LaFranco <flafranco@...>
 

The 5 pole 2.7 KHz filter is included with the base K3 at no additional cost. Since the 2.7 KHz filter is included with all K3's I would be reluctant to sell it even if I never used SSB. Somewhere down the line a prospective buyer would expect the 2.7 KHz filter to be there.

Buy the way, if you wanted to upgrade to the 8 pole 2.8 KHz filter, Elecraft will allow $79 dollars off the price of the upgrade at the time of K3 purchase.

73,
Frank - W6NEK

----- Original Message -----
From: bill_w4zv
To: Elecraft_K3@...
Sent: Monday, September 24, 2007 3:11 AM
Subject: [Elecraft_K3] Re: Other filters in the K3


Hi Eric,

--- In Elecraft_K3@..., "Eric C. Swartz"
<wa6hhq_lists@...> wrote:

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.
I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).

I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.

73, Bill





Yahoo! Groups Links


Re: Other filters in the K3

Larry Phipps <larry@...>
 

Maybe Eric can comment further on this, but according to his talk at
W9DXCC, the Elecraft filters are a slightly different design to
optimize IMD compared to the Yaesu ones... I assume because the xtals
themselves have different motional parameters. Maybe the circuit is
the same, but the "cut" of the xtals is different?

73,
Larry N8LP


--- In Elecraft_K3@..., Hans Remeeus <hans@...> wrote:


Thanks Toby.

When it is not fully plug-in I will not try to put the F-1000D's
filters
into the K3.

It's better to sell the 1000D's filters and pay $90 for a filter which
will fit.


73,
Hans Remeeus (PA1HR)
http://www.remeeus.eu
Communication is about people, the rest is technology.



Toby Deinhardt schreef:


Re: Other filters in the K3

bill_w4zv <w0zv@...>
 

Hi Eric,

--- In Elecraft_K3@..., "Eric C. Swartz"
<wa6hhq_lists@...> wrote:

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.
I understood the TX filter will be firmware menu selectable. If Hans
plans to use the rig on CW only, why couldn't he specify a filter
suitable for CW transmission (e.g. 1000 or 500 Hz)? As long as he
never used his K3 on SSB, he could sell his 2.7 kHz (if indeed he is
forced to buy one initially).

I do hope you have not changed your mind about allowing TX filters to
be menu selectable. Even though I will have a 2.7 kHz in my unit, I
plan to use a 500 Hz filter on CW transmit for signal quality reasons.

73, Bill


Re: [Elecraft_K3] Re: Other filters in the K3

Toby Deinhardt
 

Good Morning,

Apparently the way the crystals are cleaned prior to assembly
More about this at <http://www.xs4all.nl/~martein/pa3ake/hmode/roofer_intro.html>:

<============================================================>

Building the roofing filter from discrete parts does not
guarantee a very good intercept point by itself. It all
comes down to the quality (=linearity) of the individual
components. Especially the crystals! Because of the digital
revolution, quartz crystals have become mass produced
components (mainly China these days) and are therefore
very cheap, which is good. But crystals that are manufactured
to be used in crystal oscillators for digital circuits do
rarely have the quality that is needed to construct a
high-end crystal filter. Their Q is good enough to get
an oscillator starting reliably and keep it going, but
usually not good enough to produce filters with very low
insertion loss. Even worse, the 'oscillator-grade'
crystals also lack linearity. The surface finish plays
a big role in the linearity of the quartz. Particles
(micro dust) polluting the surface of the quartz are
known to cause IMD. To make things considerably worse,
the IMD they cause is not following 3rd order law by
any means.

etc. etc. etc.

<============================================================>



Very worth while reading imho.


vy 73 de toby


Re: Other filters in the K3

Julian <julian@...>
 

--- In Elecraft_K3@..., "bill_w4zv" <w0zv@...> wrote:

Not recommended. Different mechanical pinout and I understand Inrad
must carefully select 8-pole filters for IMD performance in the K3.
Although your FT-1000D filters might be OK in its 2nd IF, they *might
not* provide the IMD performance needed in the K3's 1st IF. There is
apparently some unspecified parameter in the filter affecting IMD
performance so I would definitely not use any filters except Elecraft's.
Interesting item in Technical Topics in the latest RSGB RadCom about
this. Apparently the way the crystals are cleaned prior to assembly
can affect the IMD performance. Many filter manufacturers don't take
the extra trouble over this because but adds to the cost. Certainly a
good argument for sticking with the Elecraft filters.

Julian, G4ILO


Re: [Elecraft_K3] Re: Other filters in the K3

Hans Remeeus <hans@...>
 

Thanks again, Bill. Very useful information!


73,
Hans Remeeus (PA1HR)
http://www.remeeus.eu
Communication is about people, the rest is technology.



bill_w4zv schreef:

--- In Elecraft_K3@... <mailto:Elecraft_K3%40yahoogroups.com>, Hans Remeeus <hans@...> wrote:
>
>
> Hi Bill,
>
> Thank you so much for this very interesting information!
>
> This is very good to know before to decide and how to place the order.
In case you have not seen it, also check the 8-pole filter plots here:
http://www.elecraft.com/K3/K3_8_pole_plots.htm <http://www.elecraft.com/K3/K3_8_pole_plots.htm>
...and 5-pole info here:
http://mailman.qth.net/pipermail/elecraft/2007-September/073452.html <http://mailman.qth.net/pipermail/elecraft/2007-September/073452.html>
... some of my personal thoughts:
http://mailman.qth.net/pipermail/elecraft/2007-September/073462.html <http://mailman.qth.net/pipermail/elecraft/2007-September/073462.html>
http://mailman.qth.net/pipermail/elecraft/2007-September/073737.html <http://mailman.qth.net/pipermail/elecraft/2007-September/073737.html>
...and regarding the 250/200 BW filters, see second paragraph from the
bottom:
http://mailman.qth.net/pipermail/elecraft/2007-September/073959.html <http://mailman.qth.net/pipermail/elecraft/2007-September/073959.html>
73, Bill


Re: Other filters in the K3

Eric Swartz - WA6HHQ, Elecraft
 

2.7 kHz. 2.1 kHz is way too narrow for SSB TX.

73, Eric

--- In Elecraft_K3@..., Doug Faunt N6TQS +1-510-655-8604
<faunt@...> wrote:

Err, is the minimum 2.7kHz or 2.1kHz?

73, doug


Re: [Elecraft_K3] Re: Other filters in the K3

Doug Faunt N6TQS +1-510-655-8604
 

Err, is the minimum 2.7kHz or 2.1kHz?

73, doug


From: "Eric C. Swartz" <wa6hhq_lists@...>
Date: Mon, 24 Sep 2007 01:01:59 -0000

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.

73, Eric WA6HHQ


Re: Other filters in the K3

Eric Swartz - WA6HHQ, Elecraft
 

You must have at least one SSB b/w filter in the K3 when we ship. (2.7
kHz or higher.) These filters are used on TX and must be in the rig.

73, Eric WA6HHQ