Elad Fdm77 Hf Receiver Operating Manual

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                  Mode A CW demodulation using BFO for 800 Hz audible tone.  
 
 
                Mode A CW demodulation using BFO for 1.100 Hz audible tone.  
    

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Mode B CW demodulation with fixed BFO and Zero beat. To hear the 800 Hz   
A udible tone a different VFO tuning will be required.  
   
3.5.5 AGC Operation & Control  
  
The  operator  is  allowed  to  work  with  Automatic  AGC  (  Slow  or  Fas t)  or  with  Manual  AGC.  
When working with Manual AGC the gain is varied through the slide bar control.  
  
3.5.6 Using the Notch function.  
  
The  filter  control  section  includes  the  possibility  to  use  two  notch  each  one...

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                      Desired signal at 1.125 HZ with two interfering tones (750 Hz and 1.500 Hz).  
 
 
                      Thanks to filter notch 1 the interfering signal at 750 Hz has been eliminated.  
      

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Using the notch filters. 
 
 
                  Thanks to filter notch 2  the interfering signal at 1.500 Hz has been eliminated.  
 
 
                  Both interfering signals have been eliminated using notch 1 and 2  
      

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3.5.7 Audio spectrum and audio oscilloscope. 
 In addition to the 12KHz input signal also the demodulated audio signal can be displayed on a  
level/frequency diagram in the lower left side of the advanced window and in a level/t ime diagram 
i n the lower right side.  
  
3.6 Main SETUP  
In  the  window  TUNING  of  the  cockpit  the  button  SETUP  allow  to  enter  the  MAIN  SETUP 
function. Just click the SETUP button and a new window “MAIN SETUP” w ill popup to allow the 
setting of...

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Choose Dev In/Out. If you have two sound cards installed in your PC the selection of the car d you 
want to use as input (Recording mixer) and output ( Speaker Mixer) device is allowe d. 
Choose file.  The selection of a test signal to be used in demo mode is allowed.  
Flip  input  spectrum.  To  be  used  with  down -converters  only  and  when  a  spectrum  inversion  is 
observed on the Spectrum & Scope Viewer. Not checked is the  Default .  
Calibration.  This is a facility provided...

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3.7 AF Control. 
  
In  the  lower  right  side  of  the  cockpit  the  AF  CONTROL  window  all ow  to  set  up  the  sound 
reproduction that best conforms the operator preferences. The AF f requency spectrum is divided in 
6  octaves  with  high/low  tone  slide  bar  controls.  Moreover  volume  control  i s  added    with  mute 
control (toggle button). This volume controls the out level to the sound boar d. The operator should 
set  the speaker volume through the WINDOWS mixer...

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4. Remote control of FDM -77.  
This function is not released so far. It consists of an option (not included in the FDM77, but  
available as separate option) to allow the remote control of a receiving stati on equipped with 
FDM77 (Server station) through internet (TCP/IP) simply using a PC with the ELAD S oftware 
radio installed (Client station).  
The client station can control the remote receiver and have the audio stream  reproduced simply 
using WINAMP.  
More details will be...

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5. PC sound card mixer setting. 
In order to get the  best performances a proper setting of the sound card Mixer must be done.  
  
Open the mixer and disable the mike and line as inputs for the speakers.   
 
 
  
Wave and Volume only should be enabled for sound reproduction.  
 
 
  
Open the mixer and enable as recording input the line input.   
    

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The recording level must be adjusted carefully in order to have a good decoding of  DRM and a ll 
the analogical mode CW, SSB, AM and FM.