Elad Fdm77 Hf Receiver Operating Manual

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step. A shortcut for changing a single digit can be activated through the “Q”, “W”,”E”, “R”, 
“T”,  “Y”,  “U”,  “I”  keys  (increment)  and  “A”,  “S”,”D”,  “F”,  “G”,  “H”,  “J”,  “K”  (decreas e). 
The  “I”  and  “K”  keys  move  1  Hz  digit  and  up  to  10  MHz  the  “Q”  and  “A ”.     Note  that  the 
arrows on the PC keyboard control the frequency only if the window of the coc kpit is active (i.e. the 
upper bar of the window must be blue and not gray).  
Any frequencies outside...

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2.5 Mode Selection 
Conventional  modes  (  CW,  LSB,USB,AM,FM)  are  simply  selected  by  clic king  on  the  relevant 
buttons in the MODE window of the cockpit.  
DRM  mode  is  selected  through  the  DRM  SET  button.  By  clicking  on  the  DRM   SET  button  a  new 
DRM  Setting  window  will  open  allowing  to  choose  the  preferred  DRM   application    to  be  used  to 
decode the digital signal. There are two options:  
If  DRN  Int.  is  selected  the  DRM  signal  is...

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2.6 Band Selection. 
  
No  band  selection  is  required  to  explore  the  whole  range  of  frequencies .  Simply  select,  with  the 
VFO, Keyboard and/or Memory the desired frequency.   
The internal pre -selector filter will be automatically activated in the RF Hardware fr ont-end.  
  
3 Operation of the receiver – Advanced  
  
The  set  up  of  the  RF  front -end  input  has  a  strong  impact  on    the  quality  of  the  reception.  In 
particular the use of the preamplifier...

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3.3 Frequency scanning 
  
By clicking the SCAN button the scan panel will popup . Before starting the scan Start  and Stop 
frequencies must be selected together with the Time hold ( 200 mS is the default ) , Step frequency 
and Step X (of the frequency axis).   
 
 
   
At the end of the scanning process a diagram with S -meter level and frequencies will be displayed.  
Passing with the mouse over the diagram the relevant frequencies will be displa yed on the 
frequency windows located...

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3.4 Memories  
  
3.4.1 Saving a station/frequency in the memory.  
  
When the desired station/frequency is tuned simply click the memory button to open the MEMO RY 
file. Click on the “Save in Mem” Button and the data will be inserted in the ta ble. Click Close to 
exit.  
 
 
      
3.4.2 Recalling a station/frequency from the memory.  
  
Open the MEMORY table and then double click on the row with the station/frequency you want  to 
recall and the new frequency will appear on the...

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3.5 Advanced controls. 
  
In the TUNING window an ADV button is included.   
  
Clicking  on  this  button  a  new  ADVANCED  window  will  pop -up  showing  the  DSP  function  and 
controls.  The  advanced  window  includes:  Input  Spectrum,  Audio  Spectrum,  Audio  Oscilloscope, 
DSP Filter BW, IF SHIFT, CW MODE and AGC CONTROL.   
 
 
 
   

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3.5.1 Input Spectrum.  
  
A Low Frequency real time spectrum diagram is available in the uppe r left side of the window . In 
the  diagram  the  12  KHz  signal  level  at  the  input  of  the  soundcard  i s  displayed    in  dB    and  the 
frequency in KHz. Zoon function is also available for both the level and frequency.   
The signal pass -band is showed with black/dashed area together with two notch filters if enabled.  
Once  the  ADVANCED  window  is  made  active  (eventually  by...

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                LSB signal received with 2.5 KHz BW DSP filter  
 
 
              AM signal received with 4.0 KHz BW DSP filter  
      

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                FM signal received with 5.0 KHz BW DSP filter.  
  
3.5.3 IF Shift control.  
This control allow the operator to move the 455 IF band pass filter with reference t o the tuned 
signal in order to attenuate an on band interfering signal.    
 
 
                 Display of the tuned AM signal together with a CW interfering signal.   
(Interfering signal 1Khz down of  the carrier frequency)     

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               IF band pass filter shifted 500 Hz up to attenuate the CW interfering signal.  
 
3.5.4 CW MODE  
  
In the middle right side a CW mode filter control is available with seve ral operative mode. 
  
Mode A  : This operative mode is very similar to old style radio recei vers provided with the BFO 
control.  Move  the  frequency  slide  to  choose    the  tone  of  CW  signal  that   best  conform  to  your 
preferences.  In  this  way  you  don’t  need  to  move  the  main...