( Be sure to Refresh your pages, each visit, { F5 }
( web-site construction has been ongoing since 1994, for 27 years

---    all about Analog Active Filters
and Electronic_Technology
                        and Ham Radio circuits
            for Receiving Morse-Code

Original Radical Analog Designs for 'CW' filtering circuits

***************** Ham K4KKQ running CW for 63 years **************************************************

>> AFX Advanced Filter ( read AFX basic FIRST )

>>   AFX Roof-Triad Filter ( read AFX basic FIRST )

>> AFX 'V'_ _Variable f() Filter    ( read AFX basic FIRST ) ( AFX 'V' is the Best-of-Class project )

!!! Advanced Variable Frequency version of the  'AFX' project
( AFX 'V' is the Best-of-Class project )

>> AFX 'V'__Variable f() Filter    ( read AFX basic FIRST )   ( AFX 'V' is the Best-of-Class project )

>> Summary List for AFX 'V' :
(1RL-Manual Control) (3RL-Manual Control)    (1RL-Fet Control)   (3RL-Fet Control)

*********************************************************************************

>> AFX Basic Filter    is the current page --- please read through this page first !

>> then read the sub-pages for greater basic details.

*********************************************************************************

Below: Transient Plot shows Phase Delays and inter-actions.
Triple-Signals are phase-shifting across time. (600Hz , 700Hz , 800Hz )
Note: Filter (top trace ) forces phase shifting on input signal and produces a symetrical output signal.
Note: Filter (blue trace) responds to the beat frequencies with peaks and nulls in its output.



/glene77is/GC_ET_files/PD1-2-TS-24ms-150803-0800.jpg

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PreRequisite :

This is not an academic Algebra / Calculus based tutorial.
It is expected that the reader will have a good understanding
of Active BandPass Filter Concepts.

This website & project does not contain an in-depth presentation
of basic Delyanis Multi-Feed-Back Filter , nor derivatives.

All concepts presented herein are common to Active BandPass Filters
as presented in tutorials and academic course-work
presented for Electrical Engineering students.
ONLY the SYNTHESIS of common ideas into radically new approaches is different.

Your Imagination is more important than prior academic learning.

About this project :

This project is our Current research in Analog I.C. Applications,
     2014 thru 2021,
as applied to CW (morse code) Radio Operations
... posted at www.GeoCities.WS/glene77is
... posted at www.ResearchGate.net

Our Analog Project shows the evolution of filter design
from common Active BandPass circuits into Active Phased-Filtered circuits.

() This project has produced a Series of Analog Filters aproaching DSP quality
()      which Emphasize Original Radical Designs .
()      which Emphasize Phased-Filters and Parallel-Channel-Filters to generate Dual-Notch effects.
() This experimental project
()        is about Analog Electronic Technology applied to Amateur Radio operations.
()        is applied to Narrow Band-Pass Morse Code CW operations.

Our project's Applications could also include in-lab analog instrument filters
where the circuit is proto-boarded and no PC/computer required .

****************************************************************************************************
Basic AFX circuit includes these modules:

1. Pre-Amp with Limiter
2. Roofing Parallel-Channel-Differential Filter
3. Active-Log_limiter
4. Quad-MFB audio filter
5. Differential-Phase Filter with Double-Notched Band-Passband.
6. Audio out 0.5 W class-B

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****** The AFX 'basic' designs include these features :
******       BandPass 90Hz @ -3dB and 340Hz @ -60dB,
****** SideBand Spread = 5Hz per dB attenuation
****** Dual-Notch BandPass = -90 dB @ 350Hz bandpass
*******      Variable-Frequency PassBand (600-700-800)



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Below are the Functional Blocks of the General AFX circuit development

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the "AFX" B.A.S.I.C. Simple Schematic (basic)

( goto Schematics Page for Hi-res )

where it all started simply

*************************************************************************************************************************************

the "AFX" Advanced Schematic ( Phase-Filtered Dual-Notch version)
( goto Schematics Page for hi-res )

*************************************************************************************

Revised details and hi-res schematics are in the section "AFX" 'V'
for the Phase-Filtered Dual-Notch Filter developments

*************************************************************************************

******************************************************************************************************

*** Below : the TUTORIAL Pages :

*** This Page is an Index into the Modular Stages that Build the AFX

******* below : each of the linked pages contain detailed discussion and schematics and bode plots
******* below : each of the linked modular circuits are included in the advanced "AFX" projects.

_____________the AFX Roofing-Triad-Differential Filter details:   (GC_ET_AFX_CW_Roof.html)

___________________________________________________________________________________________________________________________________________________________________________________________



_______ the   AFX Active-Log-Limiter stage details :   (GC_ET_AFX_CW_Limiter.html)


____________________________________________________________________________________________________________________________________________________________________



______________the  AFX Quad-MFB Filter details (GC_ET_AFX_CW_Filter.htm)

_____________________________________________________________________________________________________________________________________________________________

_

Differential-Phase-Filter
& Integrating-Phase Filter
& Q20 Sharp Variable f(0) filter

AFX Phase-Filter Circuit_

(GC_ET_AFX_CW_FiltDIQ.html)

When Combined with Roof-Triad-Differential-Filters,
and the Quad-MFB-Band-Pass Filters,
the "A" stage Phase-Filter can produce Dual-Notches at -98 dB
    Variance = 7 Hz sideband spread per dB attenuation

Refer to the above link for the details of the Phase-Flter stages.

"A" narrow Notch stage on left. "B" Wide stage center. "C" Q20 Sharp Band-Pass Follower Filter.

^{_____________________________________________________________________________________________________________________________________________}^{_______________________________}^{_________________________________________}

^{_________    AFX Audio Driver with Pulse-Signal-Shaping (GC_ET_AFX_CW_Audio.html)}

^{***************************************************************************************************************}

Above are the Functional Blocks of the General AFX circuit development

^{***************************************************************************************************************}

************************************************************************************

( Josef Punčochář )

Associate Professor

VŠB-Technical University of Ostrava, · Department of Electrical Engineering

_______Original Design for Positive-FeedBack BandPass Filter. ( GC_ET_PFB-rg.html )
___Positive-FeedBack_BandPass_Filter ( GC_ET_PFB-rg.html )

___Positive-FeedBack_Sine_Oscillator, with one resistor f(0) control_and magnitude_control.

*** Positive-FeedBack-BandPass_Circuits

GC_ET_PFB-bpf.html Positive FeedBack BandPass Filter

GC_ET_PFB-osc.html Positive FeedBack Osc

*********************************************************************************************

**********************************************************************************************************

--- all about Analog Active Filters and Electronic_Technology and Ham Radio circuits for Receiving Morse-Code

Original Radical Analog Designs for 'CW' filtering circuits

***************** Ham K4KKQ running CW for 63 years **************************************************

__________________________________________________________________________________________________________________

Be sure to read the page on < Radical All-Pass Projects >

Non-Linear Non-Resonant AllPass_Experimental_Filters Dual-Notch Phase-Filter Projects

********( Home )********************************************************************************

!!! Advanced Variable Frequency version of the 'AFX' project ( AFX 'V' is the Best-of-Class project )

>> AFX 'V'__Variable f() Filter ( read AFX basic FIRST ) ( AFX 'V' is the Best-of-Class project )

>> Summary List for AFX 'V' : (1RL-Manual Control) (3RL-Manual Control) (1RL-Fet Control) (3RL-Fet Control)

*********************************************************************************

>> AFX Basic Filter is the current page --- please read through this page first !

*********************************************************************************

/glene77is/GC_ET_files/PD1-2-TS-24ms-150803-0800.jpg

**********************************************************************************

PreRequisite : This is not an academic Algebra / Calculus based tutorial. It is expected that the reader will have a good understanding of Active BandPass Filter Concepts.

This website & project does not contain an in-depth presentation of basic Delyanis Multi-Feed-Back Filter , nor derivatives.

All concepts presented herein are common to Active BandPass Filters as presented in tutorials and academic course-work presented for Electrical Engineering students. ONLY the SYNTHESIS of common ideas into radically new approaches is different.

Your Imagination is more important than prior academic learning.

About this project :

***********************************************************************************

******************************************************************************************

*********************************************************************************************************************

the "AFX" B.A.S.I.C. Simple Schematic (basic)

*************************************************************************************************************************************

the "AFX" Advanced Schematic ( Phase-Filtered Dual-Notch version) ( goto Schematics Page for hi-res )

******************************************************************************************************

*** Below : the TUTORIAL Pages : *** This Page is an Index into the Modular Stages that Build the AFX ******* below : each of the linked pages contain detailed discussion and schematics and bode plots ******* below : each of the linked modular circuits are included in the advanced "AFX" projects.

___________________________________________________________________________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________________________________________________

_____________________________________________________________________________________________________________________________________________________________

_____________________________________________________________________________________________________________________________________________________________________________________________________________________

************************************************************************** -------------------------------------------------------------------------------------------------------- --- More 'small' projects ---------------------- *** ET_Fliege_Filter

**************************************************************************

--------------------------------------------------------------------------------------------------------

*** ET_Filter-Incremental-Tuning

*** GC_ET-OPA-AC.html OpAmp with Active Phase Compensation

*** CALF_a-Fine-Club-Project-Kit-by-KC9on

*** ET_State-Variable_Filter *** ET_Antoniou_Filter (" the Gyrator Filter")

*** ET_State-Variable_Filter

*** Phased-Signal Analysis : **************************************************************************

*** Early Parallel-Dual-Channel Developmental circuits

*** Notched-Filter_7N

*** Notched-Filter_AAN

___Positive-FeedBack_Sine_Oscillator, with one resistor f(0) control_and magnitude_control.

*** Positive-FeedBack-BandPass_Circuits GC_ET_PFB-bpf.html Positive FeedBack BandPass Filter GC_ET_PFB-osc.html Positive FeedBack Osc

--- all about Analog Active Filters
and Electronic_Technology
and Ham Radio circuits
for Receiving Morse-Code

* Ham K4KKQ running CW for 63 years **********************************

( Home )****************************************************************************

!!! Advanced Variable Frequency version of the 'AFX' project
( AFX 'V' is the Best-of-Class project )

>> Summary List for AFX 'V' :
(1RL-Manual Control) (3RL-Manual Control) (1RL-Fet Control) (3RL-Fet Control)

PreRequisite :

This is not an academic Algebra / Calculus based tutorial.
It is expected that the reader will have a good understanding
of Active BandPass Filter Concepts.

This website & project does not contain an in-depth presentation
of basic Delyanis Multi-Feed-Back Filter , nor derivatives.

All concepts presented herein are common to Active BandPass Filters
as presented in tutorials and academic course-work
presented for Electrical Engineering students.
ONLY the SYNTHESIS of common ideas into radically new approaches is different.

the "AFX" Advanced Schematic ( Phase-Filtered Dual-Notch version)
( goto Schematics Page for hi-res )

* Below : the TUTORIAL Pages :

* This Page is an Index into the Modular Stages that Build the AFX

* below : each of the linked pages contain detailed discussion and schematics and bode plots
* below : each of the linked modular circuits are included in the advanced "AFX" projects.

^{_____________________________________________________________________________________________________________________________}^{_}^{___________________________}

************************************************************************

--------------------------------------------------------------------------------------------------------

--- More 'small' projects ----------------------

* ET_Fliege_Filter

* ET_State-Variable_Filter

* ET_Antoniou_Filter (" the Gyrator Filter")

* Phased-Signal Analysis :

************************************************************************

* Positive-FeedBack-BandPass_Circuits

GC_ET_PFB-bpf.html Positive FeedBack BandPass Filter

GC_ET_PFB-osc.html Positive FeedBack Osc**