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Radio Receiver
Selects RF frequency ( I.F.  or  Direct Conversion ) 
DeModulates to Audio

Pass-Band BandWidth 3 KHz 
center Audio at 700 Hz

Audio Vout level is adjustable to a standard 1 V audio,   
  

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PreAmp with Gain Control
and OverVoltage clamp. 

Vout audio is system standard 1 V audio,  

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Roof Triad Differential Filter
3 OpAmps
f(0) = 700 Hz
BandPass = 350 Hz
SideBand Attenuation = -27 dB per Octave,  per Triad

Roofing Filter is for clarity in CW  operations 
(1) Reduce wide sideband signals
without distorting the central passband. 
(2) Form Symetrical waveforms for the Active Limiter, 
to reduce InterModulation Distortion during hard limiting. 

Vout audio is system standard 1 V audio.

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Active Limiter based on Logrithmic Negative FeedBack
PreAmp can drive/force Limiter into action
         for use with weak signals, as a form of AGC.
The "AFX" Active Limiter has noise reduction and AGC features .

Vout audio is system standard 1 V audio.

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Quad Multi-FeedBack BandPass Filters , Q from aprox. 2  to aprox. 7 .

Quad MFB Filter module is where main Variable f(0) is to be made. 

**************************************************************************** 
Incoming Signal f() is NOT Altered 
Designed for Single User Control to shift Filter f()
from 600Hz continuously to 800Hz. 
Will maintain aprox. "Q" and "Gain". 
Current design uses four JFET to parallel R(freq)
on each of the four MFB filters.
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Normal Selectivity may be done
by taping any of the Quad Filter stages 

Vout audio is system standard 1 V audio.

Two additional Very Sharp MFB filters
will be tacked on after the Dual-Notch-Generator Stage. 

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Differential Dual-Notch Generator Stage.
BandPass= 100 Hz @ -3 dB
BandPass= 300 Hz @ -48 dB

SideBand= +/- 175 Hz,  at least -48 dB  

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Sharp Filters with variable f(0) ,
BW=70Hz at Q=10
BW=35 at Q=20

Pull Dual-Notch Depth down another  - 30dB 

F(0) can be varied within the main Quad PassBand. 
User adjustable. 

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Sharp Filters with variable f(0) , BW=70Hz at Q=10 and BW=35 at   Q=20 . 

F(0) can be varied
within the main Quad PassBand.  
User adjustable. 

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Audio power.

User adjustable.