<< Software settings.  20210903

This active loop antenna gives about 30dB lower output, compared with a 1/2 wave dipole antenna, when both work on the same frequency and in the same field strength. By adjusting the SDR software for 30dB extra software gain (or "Visual gain"), this antenna system is calibrated to give the same S-meter readings compared with that dipole antenna.

                  During evening hours very strong signals are received.
To prevent saturation of a wide band SDR receiver (like the AirspyHF+), 12dB attenuation is needed.

                             Smeter calibration for this active loop antenna :
SDR# : Set "Att" to -12dB. Overload is now prevented AND S-meter readings will be correct.

SDRconsole : Set "Visual Gain = +30dB", the S-meter is calibrated.
Setting "Att" to -12dB prevents overload, but S-meter readings will not be insfuenced.

 
            SDR#
 Bandwidth      : "610 kHz"
HF AGC         : "Off"
HF PREAMP : "Off"
ATT                 : "-12 dB".		        SDRconsole
Bandwidth  : "768 kHz"
 AGC            : "Off"
ATT              : "Off" or -12 dB.
Preamp        : "Off"
Visual gain : "+30dB".