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WiNRADiO G39DDC User’s Guide
86
If HF sensitivity appears poor, please first ensure that the attenuator is
disabled.
Preamplifier
For the VHF/UHF/SHF section of the receiver, the Preamp button engages a
low noise preamplifier, which adds approx 10 dB of amplification to the front-
end, and so increases sensitivity.
Please note that the actions of both the attenuator and preamplifier are
compensated for by the S-meter. This means that the S-meter always
displays the actual signal strength at the antenna input, within the
available measurement range.
S-meter
The WiNRADiO Excelsior receiver is equipped with a very sensitive and
selective Signal Strength Meter (S-meter) which makes it possible to
measure peak or RMS signal level in dBm, µV or S-units, within the
demodulator filter passband. The measurement units are selected by
appropriately marked buttons at the bottom of the display.
selective Signal Strength Meter (S-meter) which makes it possible to
measure peak or RMS signal level in dBm, µV or S-units, within the
demodulator filter passband. The measurement units are selected by
appropriately marked buttons at the bottom of the display.
The S-meter also shows the currently selected value of the squelch (the red
section at the bottom side of the scale) when the squelch is enabled. When the
signal strength falls under the squelch level (i.e. the needle falls in the red
region and turns red also), the receiver audio will be muted and the word
“Squelched” will appear inside the S-meter.
section at the bottom side of the scale) when the squelch is enabled. When the
signal strength falls under the squelch level (i.e. the needle falls in the red
region and turns red also), the receiver audio will be muted and the word
“Squelched” will appear inside the S-meter.
The squelch value is always indicated in dBm (even if the signal strength is
displayed in S-units or microvolts).
displayed in S-units or microvolts).