[K3] K3 Utility settings for CW filters

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[K3] K3 Utility settings for CW filters

k5oai
I have both a 5 pole 500hz and a 5 pole 200hz cw filter.
What is the suggested setting for the db gain for those filters?

Also I remember reading a suggestion to
use the K3 utility to set the filters
slightly higher than the actual width,
example set the width of the 500hz filter to 550hz
and the 200hz filter to 250hz

I have forgotten the rational for this,
can someone enlighten me, again. <g>
--
GB & 73
K5OAI
Sam Morgan
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Re: [K3] K3 Utility settings for CW filters

Dick Dievendorff
This is in the owner's manual, and there's a corresponding table in K3
Utility Help on the Crystal Filter configuration page.

I'm afraid the table will format strangely in text e-mail.  The page is
indexed under "filter configuration". Look for the heading "Loss
Compensation".


73 de Dick, K6KR


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Sam Morgan
Sent: Monday, January 03, 2011 4:08 PM
To: [hidden email]
Subject: [Elecraft] [K3] K3 Utility settings for CW filters

I have both a 5 pole 500hz and a 5 pole 200hz cw filter.
What is the suggested setting for the db gain for those filters?

Also I remember reading a suggestion to
use the K3 utility to set the filters
slightly higher than the actual width,
example set the width of the 500hz filter to 550hz and the 200hz filter to
250hz

I have forgotten the rational for this,
can someone enlighten me, again. <g>
--
GB & 73
K5OAI
Sam Morgan
______________________________________________________________
Elecraft mailing list
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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Re: [K3] K3 Utility settings for CW filters

Arie Kleingeld PA3A-2
Dick,

To come up with a optimal (?) setting I worked as follows:

Connected the elecraft XG-2 generator, 40m, S9 setting.
Set the K3 AGC to off and the display to dBV
Set Mode to cw, tuned on exact spot freq.

All frequency offsetsfor the filters were set as indicated (have 2.7,  
2.1, 400 and 200) and checked. Worked with these setting for the past 2
years and worked just as expected.

Now for setting the filter gains:
I tried to achieve a simular dBV reading for all filters in this set-up.
I tuned around the spot freq for max dBV readout.
The K3 came up with +5dBV with enough room above and under this level
for the 2.7 filter.
I used that as a reference.
Then switched in the different filters and tried to compensate the loss
in dBV.

My settings for the filters are now (for all filters around a +5dBV
reading):
2.7k  0dB
2.1k  3dB
400   7 dB
200   8 dB  (200Hz is still 2dB short of the 2.7k level)

Ofcourse the dBV readout may differ with bandwidth (by definition) but I
can clearly hear the difference in level. Not sure how much I need to
compensate this measurement for bandwidth when using the XG2. at S9 level.

Has someone measured it like this?

I know that the K3 agc or my manual RF will compensate it all but I am
trying to understand a few things and why it is a setting in the K3.

Help and guiding will be much appreciated.


73
Arie PA3A
k3 #1255


Op 4-1-2011 1:25, Dick Dievendorff schreef:

> This is in the owner's manual, and there's a corresponding table in K3
> Utility Help on the Crystal Filter configuration page.
>
> I'm afraid the table will format strangely in text e-mail.  The page is
> indexed under "filter configuration". Look for the heading "Loss
> Compensation".
>
>
> 73 de Dick, K6KR
>
>
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