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m0cemdave · 3rd Mar 2021, 11:55 pm

The construction notes for the ASL5 actually suggest that a CSL4 can be added for "even greater selectivity" and I have seen a few examples built like that.
However it's pointless really because either filter works very well on its own. The CW filter is very sharp and surprisingly good at pulling a signal out of noise and nearby QRM.

I have several of these boards either as standalone amplifiers (ASL5) or built into homebrew receivers (CSL4).

It's quite easy to change the CW filter values - all mine have been set to 750Hz and are about 200Hz wide.

You may find it useful to remove the CSL4 and use it independently, if you have an existing receiver that would benefit from the addition of a tight CW audio filter.

3rd Mar 2021, 11:55 pm	#6
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,223	Re: Howes audio filters The construction notes for the ASL5 actually suggest that a CSL4 can be added for "even greater selectivity" and I have seen a few examples built like that. However it's pointless really because either filter works very well on its own. The CW filter is very sharp and surprisingly good at pulling a signal out of noise and nearby QRM. I have several of these boards either as standalone amplifiers (ASL5) or built into homebrew receivers (CSL4). It's quite easy to change the CW filter values - all mine have been set to 750Hz and are about 200Hz wide. You may find it useful to remove the CSL4 and use it independently, if you have an existing receiver that would benefit from the addition of a tight CW audio filter. Attached Thumbnails Last edited by m0cemdave; 4th Mar 2021 at 12:15 am.