Robotron Pty Ltd G9P 用户手册
WiNRADiO G39DDC User’s Guide
35
For LSB mode, dragging the right-hand edge of the greyed-out filter passband
results in tuning, dragging the left-hand edge results in adjusting the filter
bandwidth. For USB mode, the opposite applies. The edge that is used for
tuning is highlighted for operator convenience.
results in tuning, dragging the left-hand edge results in adjusting the filter
bandwidth. For USB mode, the opposite applies. The edge that is used for
tuning is highlighted for operator convenience.
IF Shift and Passband Tuning
Dragging the greyed-out demodulator filter passband in the DDC2 spectrum
will result in tuning the receiver in a manner somewhat similar to the IF Shift
function in conventional receivers. The passband will move inside the
displayed spectrum and the tuned frequency will change accordingly.
will result in tuning the receiver in a manner somewhat similar to the IF Shift
function in conventional receivers. The passband will move inside the
displayed spectrum and the tuned frequency will change accordingly.
In a DDC-based receiver, “IF Shift” is in fact a misnomer because there is no
“intermediate frequency”, but as this is a time-honored and commonly used
term for this function, we will still use it here for convenience.
“intermediate frequency”, but as this is a time-honored and commonly used
term for this function, we will still use it here for convenience.
IF shift makes it possible to tune the receiver by positioning the demodulator
filter precisely over the spectrum of the received signal, while keeping the DDC
passband located exactly where it is.
filter precisely over the spectrum of the received signal, while keeping the DDC
passband located exactly where it is.
This makes it possible to quickly and visually tune to another station
represented by a signal peak in the spectrum. However, it is not very suitable
for the AMS, USB, LSB, ISB, DSB and CW modes if you only wish to adjust
the filter passband position slightly for the station you are currently receiving
(for example in order to avoid interference from an adjacent channel). If you do
this, and you are, for example, tuned to an AM station using the AMS mode, or
an SSB station using the USB or LSB modes, then moving away from the
represented by a signal peak in the spectrum. However, it is not very suitable
for the AMS, USB, LSB, ISB, DSB and CW modes if you only wish to adjust
the filter passband position slightly for the station you are currently receiving
(for example in order to avoid interference from an adjacent channel). If you do
this, and you are, for example, tuned to an AM station using the AMS mode, or
an SSB station using the USB or LSB modes, then moving away from the