Swapping Standard 2.7 kHz 5-pole Filter

[Bill W4ZV]

         According to Monica at Elecraft, it's possible to swap
the standard 2.7 kHz 5-pole filter for either the 2.8 kHz 8-pole or
the 400 Hz 8-pole for an incremental $90 ($30 credit plus the
standard $120 charge for 8-pole filters), but only the 2.8 kHz
and 400 Hz may be substituted for the standard filter.

         Now if we only knew if there were any difference in
IMD/BDR performance we could make a rational decision...

                                 73,  Bill  W4ZV

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Eric Swartz - WA6HHQ]

Hi Bill,

This is incorrect. The 2.7 kHz 5-pole can only be swapped for a 2.8 kHz
or possibly the 2.1 kHz 8 pole filters. We require at least one SSB b/w
filter in each K3 as it ships since we must also transmit through the
filter for SSB and data modes. Transmitting through the 2.1 kHz filter
will limit your tx bandwidth to that value. ( I'm not aware of many
choosing the 2.1 as their only SSB filter - I may drop that as a swap
option to make sure no overly narrow TX K3s get out there and confuse
the market.)

I'll post some more detailed DR numbers on the 5 pole vs 8 pole filters
in the next couple of days. The short answer is that the 5 pole filters
have slightly less IMD3 dynamic range and a wider shape factor than the
8 pole filters, but both are very good. The 250 Hz 8-pole and the 200 Hz
5 pole are both at least 95+ dB DR3 at 5 kHz, with the 8 pole beating
out the 5 pole by several dB. We've been testing a number of each filter
on a range of K3s to make sure we can conservatively spec them across
filter variations and rig variations. :-)

One other note - The sales person you talked to is Annika. There is no
Monica at Elecraft, unless they are hiding her somewhere! ;-) She was
clear on  which filters could be swapped for the 2.7, but I'll check
with her for sure tomorrow.

73, Eric WA6HHQ
(Now back to work!)


Bill Tippett wrote:

>
>
>         According to Monica at Elecraft, it's possible to swap
> the standard 2.7 kHz 5-pole filter for either the 2.8 kHz 8-pole or
> the 400 Hz 8-pole for an incremental $90 ($30 credit plus the
> standard $120 charge for 8-pole filters), but only the 2.8 kHz
> and 400 Hz may be substituted for the standard filter.
>
>         Now if we only knew if there were any difference in
> IMD/BDR performance we could make a rational decision...
>
>                                 73,  Bill  W4ZV
> _

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Doug Faunt N6TQS [phone]]

   Date: Thu, 28 Jun 2007 21:20:26 -0700
   From: "Eric Swartz - WA6HHQ, Elecraft" <[hidden email]>

   Hi Bill,

   This is incorrect. The 2.7 kHz 5-pole can only be swapped for a 2.8 kHz
   or possibly the 2.1 kHz 8 pole filters. We require at least one SSB b/w
   filter in each K3 as it ships since we must also transmit through the
   filter for SSB and data modes. Transmitting through the 2.1 kHz filter
   will limit your tx bandwidth to that value. ( I'm not aware of many
   choosing the 2.1 as their only SSB filter - I may drop that as a swap
   option to make sure no overly narrow TX K3s get out there and confuse
   the market.)

Is 2.1kHz really overly narrow for SSB transmit?  I know people are
talking about 1.8kHz filters for RX, and it seems useless to transmit
energy that's not going to be used.  It's certainly wide enough for
data modes.  In fact, it might be useful to be able to TX through the
400Hz filter in some of those modes.

73, doug
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Eric Swartz - WA6HHQ]

I was referring to voice and I'm concerned that many will think a radio
that is -always- limited to 2.1 kHz TX is overly narrow and 'thin' sounding.

73, Eric

_..._



Doug Faunt N6TQS [phone] wrote:

>    Date: Thu, 28 Jun 2007 21:20:26 -0700
>    
> Is 2.1kHz really overly narrow for SSB transmit?  I know people are
> talking about 1.8kHz filters for RX, and it seems useless to transmit
> energy that's not going to be used.  It's certainly wide enough for
> data modes.  In fact, it might be useful to be able to TX through the
> 400Hz filter in some of those modes.
>
> 73, doug
>  

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[M0XDF]

I thought you could transmit via the currently chosen filter - have I missed
something?

On 29/6/07 09:05, "[hidden email]"
<[hidden email]> sent:

> Is 2.1kHz really overly narrow for SSB transmit?  I know people are
> talking about 1.8kHz filters for RX, and it seems useless to transmit
> energy that's not going to be used.  It's certainly wide enough for
> data modes.  In fact, it might be useful to be able to TX through the
> 400Hz filter in some of those modes.

--
A person usually has two reasons for doing something: a good reason and the
real reason. -Thomas Carlyle, historian and essayist (1795-1881)


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[M0XDF]

Thank you, seeing as one of those is mine, I'll encourage you to get on with
the production :-)


On 29/6/07 16:48, "Eric Swartz - WA6HHQ, Elecraft" <[hidden email]> sent:

> Hi David,
>
> I'll clarify. We specify globally in the K3 set up menu which filter is
> transmitted through for -each- mode. (Usually set at the factory.) That
> setting determines the TX filter regardless of which RX filter you are
> using. Right now the K3 transmits through the wider SSB filter for
> SSB/CW/Data (or the 6 kHz for ESSB with the DSP setting the actual TX
> b/w), through the 6 kHz filter for AM, and the wider FM filter for FM.
> The ultimate (narrower) TX bandwidths are actually set by the DSP.
>
> You can use any filter on RX.
>
> I can't talk much more about this now as were busy with ramping up K3
> production, but we'll update our FAQ to explain this better.
>
> 73, Eric   WA6HHQ
> ------------------
>
> David Ferrington, M0XDF wrote:
>> I thought you could transmit via the currently chosen filter - have I missed
>> something?
>>
>> On 29/6/07 09:05, "[hidden email]"
>> <[hidden email]> sent:
>>
>>  
>>> Is 2.1kHz really overly narrow for SSB transmit?  I know people are
>>> talking about 1.8kHz filters for RX, and it seems useless to transmit
>>> energy that's not going to be used.  It's certainly wide enough for
>>> data modes.  In fact, it might be useful to be able to TX through the
>>> 400Hz filter in some of those modes.
>>>    
>>
>>  
>

--
If all our misfortunes were laid in one common heap whence everyone must
take an equal portion, most people would be contented to take their own and
depart.
-Socrates (469?-399 B.C.)


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Doug Faunt N6TQS [phone]]

>>> Is 2.1kHz really overly narrow for SSB transmit?  I know people are
>>> talking about 1.8kHz filters for RX, and it seems useless to transmit
>>> energy that's not going to be used.  It's certainly wide enough for
>>> data modes.  In fact, it might be useful to be able to TX through the
>>> 400Hz filter in some of those modes.
>>>    

I seem to have lost track of (or even lost) some of the discussion here.

Ed, W0YK commented on why a somewhat wider signal is good tactics
for SSB contesting (that's much more relevant to his station then
mine), but an interesting POV.

Eric, WA6HHQ said that 2.1kHz bandwidth audio would sound "thin", and
that was apprently undesireable.  Is this just a marketing issue, or
is it truly the case for communication?  I know almost nothing about
pyschoacoustics, but I do know that once upon a time, the Collins
2.1kHz mechanical filters were the standard in military comm gear.
And I thought that the frequencies between 500Hz and 2500Hz were the
significant ones for understanding speech.
I note that the transmit audio can be tailored within that bandwidth
by the 8-band TX EQ.

The TX filter width is irrelevant if the signal going into the filter
is very clean and bandwidth limited by the DSP, but I'm a belt and
suspenders kind of person in some cases.

I also note that these are 6db bandwidths, so that frequencies on the
edge are going to be attenuated somewhat, which is why I wouldn't
choose to use a 250Hz filter for a 170Hz FSK signal (I think some of
those sidebands are significant, but haven't done any real research on
this).  But if I wanted to transmit a particularly clean signal, I
might choose the 400Hz filter for that.

73, doug

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Tom Arntzen-2]

In my opinion 2,1 khz isn't to narrow , but it would be desireable to be
able to go 2,4 or 2,7 for ragchewing.
Have you ever tried to narrow down a ESSB signal on the reciever side?
You lose talkpower and the signal sounds lousy.
Do the same with a signal transmitting standard BW will still get the
talkpower through.
So under noisy conditions if you transmitt 2,1 and the other station recieve
2,1 or 1,9
the signal will get through very good.
Another hint with ESSB if you think the "humming" is annoying you could use
the dsp.
Set for full BW but cutoff att 300 or 400hz and the signal sounds very nice.
The humming occure when they try to transmitt under about 100hz.

So fellows , if you want to try ESSB please don't go under 150 hz.
It sounds like crap .... At least to me.
A really good ESSB signal is lovly to copy , but not the 30 hz stations.

73 de Tom LA1PHA
K2/100 3829


----- Original Message -----
From: "Doug Faunt N6TQS [phone]" <[hidden email]>
To: <[hidden email]>
Sent: Friday, June 29, 2007 7:11 PM
Subject: Re: [Elecraft] Swapping Standard 2.7 kHz 5-pole Filter

>>>> Is 2.1kHz really overly narrow for SSB transmit?  I know people are
>>>> talking about 1.8kHz filters for RX, and it seems useless to transmit
>>>> energy that's not going to be used.  It's certainly wide enough for
>>>> data modes.  In fact, it might be useful to be able to TX through the
>>>> 400Hz filter in some of those modes.
>>>>
>
> I seem to have lost track of (or even lost) some of the discussion here.
>
> Ed, W0YK commented on why a somewhat wider signal is good tactics
> for SSB contesting (that's much more relevant to his station then
> mine), but an interesting POV.
>
> Eric, WA6HHQ said that 2.1kHz bandwidth audio would sound "thin", and
> that was apprently undesireable.  Is this just a marketing issue, or
> is it truly the case for communication?  I know almost nothing about
> pyschoacoustics, but I do know that once upon a time, the Collins
> 2.1kHz mechanical filters were the standard in military comm gear.
> And I thought that the frequencies between 500Hz and 2500Hz were the
> significant ones for understanding speech.
> I note that the transmit audio can be tailored within that bandwidth
> by the 8-band TX EQ.
>
> The TX filter width is irrelevant if the signal going into the filter
> is very clean and bandwidth limited by the DSP, but I'm a belt and
> suspenders kind of person in some cases.
>
> I also note that these are 6db bandwidths, so that frequencies on the
> edge are going to be attenuated somewhat, which is why I wouldn't
> choose to use a 250Hz filter for a 170Hz FSK signal (I think some of
> those sidebands are significant, but haven't done any real research on
> this).  But if I wanted to transmit a particularly clean signal, I
> might choose the 400Hz filter for that.
>
> 73, doug
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.476 / Virus Database: 269.9.14/880 - Release Date: 29.06.2007
> 14:15
>
>

--
Jeg bruker gratisversjonen av SPAMfighter for privatbrukere.
 Den har fjernet 114 søppelpostmeldinger til nå.
Betalende brukere har ikke denne meldingen i e-postene sine.
Få tak i SPAMfighter gratis her: http://www.spamfighter.com/lno


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Bill Coleman-2]

On Jun 29, 2007, at 1:36 AM, Eric Swartz WA6HHQ - Elecraft wrote:

> I was referring to voice and I'm concerned that many will think a  
> radio that is -always- limited to 2.1 kHz TX is overly narrow and  
> 'thin' sounding.

I've never gotten complaints about the K2 being too narrow, and it's  
only 2 kHz wide.

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

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com