Ver 1.0 CW Peak Filter

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  • Updated 5 years ago
Anyone tried the new CW Peak Filter yet? I see no difference at all here on any type cw signal. Pitch is set to 440.. I know there is no CW Tuning indicator yet but I m pretty sure Im close enough to the pitch frequency to see some sort of interaction with the Peak filter.  Ive tried various tuning settings..  Is there an adjustment somewhere i missed?

regards
Larry  K1UO
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K1UO - Larry

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Posted 5 years ago

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Tim - W4TME, Customer Experience Manager

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The APF center frequency is automatically set to the side tone frequency.  How are you measuring the APF's frequency response?
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K1UO - Larry

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Tim,  with my cw signal processors mounted on each side of my head...... HI HI...
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George Molnar, KF2T, Elmer

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Working well here (pitch at default 650 Hz). Just spent some time tuning around on cw this morning. Wow. Wow. And more wow. FRS has taken an excellent radio and MADE IT BETTER! Magic.

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K1UO - Larry

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wow...650...  thats way too high for me for very weak signal work but apparently you hear a difference so thats a good sign.   Apparently I have got something wrong here.  Ill try it on the main computer in the shack and not via DAX upstairs.
(Edited)
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Gerald Youngblood

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APF resides in the audio path on the radio hardware currently and will not work on DAX.
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Ken - NM9P, Elmer

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Thanks, Gerald.  I was trying to quantify the degree of peaking on the APF with my FLDigi program and wondered why I couldn't see on the screen what I obviously heard with my ears. I came to the conclusion that it was added at a stage AFTER the DAX was sampled.  You answer confirms this.  It might be a nice option to select whether or not APF is included in the DAX channel.


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K1UO - Larry

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Thanks Gerald....  This non problem reminded me to do the evaluations directly at the "Mother Ship" location rather than via DAX on the peripheral computers. 
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Al / NN4ZZ

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I have just started experimenting with the APF feature but it seems to be working pretty well on weak signals.  I'm using earphones and the powered speaker output (not DAX audio).    I noticed that using the RX Equalizer plus the APF together seems to provide a little more boost.   (see shapshot)  I couldn't find much in the way of technical information on the APF feature in the user guide.  Did I miss it or if not, can we get some details?   For example: 

1 - The APF is centered on the side tone frequency in the audio chain - how wide is the filter?  5hz, 50hz, etc

2 - How much boost (+db) is provided for the passband?

3 - How much attenuation (-db) is provided for the audio frequencies outside the filter?  There seems to be more noise than I expected.   It would be interesting to check it with a scope. 

Regards, Al / NN4ZZ





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K1UO - Larry

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OK..awesome..tried the APF directly at the main shack audio chain..FB.. pretty decent performance for the first try!  pops weak Europe signals out of the noise on 160M cw now at 2 hrs before my SS!
This is going to be interesting...  now for some diversity "deception" ... :-) to TOP it all off... pun intended.
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Ken - NM9P, Elmer

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My only comment regarding the APF other than THANKS! is wondering if the total gain can be moved down a bit.  It adds SO much gain to the desired signal that I must reduce the headphone volume... Then I must increase my sidetone to compensate. 

If the total gain of APF was reduced a bit, or better, adjustable, then it would make the noise surrounding the signal drop and it would seem that the desired signal would pop out of the noise even more.  But this is just a nit-pic. 

APF is awesome! Thanks for the unexpected but much desired new feature!

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Al / NN4ZZ

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Ken,
Your comments tie in with my questions above and also the idea I submitted a while back that would allow you to control the filter width (relative to the sidetone), peaking gain, and attenuation gain for the frequencies (hiss, noise, etc) outside the filter range.  Maybe that will come at some point.   Anyway what we have is a good improvement.  

Regards, Al / NN4ZZ

Idea is to have a control dedicated to the APF function.