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Front Panel (Right Hand Side) RHS
AF Level - Volume followed by two multifunction encoder controls. These
control RF/IF gain, BFO, demod, filter bandwidth, passband tuning and
notch filter.
The function of these two encoders is determined by the push buttons
above each of these. |
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Notch filter
Operates in any demod mode and with all bandwidths.
Offers a very deep notch with 3 width settings, small (100Hz), medium
(200Hz) and wide (400Hz). Tunable in 10Hz steps. Able to remove the strongest interfering carrier. But the
following is really neat.... Once set the notch filter will track
as you tune through the passband. In my view better
than an auto notch as you can use this in CW and data modes without the risk of it
masking the desired signal.
The lower row of red LED bars shows one segment to indicate
the notch position. This combined with the tuning aid makes it very easy
to get your notch dead on very quickly. The numeric display also shows the
exact notch position relative to the centre of the receive passband. |
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IF Filter Bandwidths
There are more than an adequate number of IF bandwidths to choose from.
Any filter is available in ALL reception modes. Each mode retains the last filter chosen. The filter
width is represented by the red LED bars below the green tuning aid. Zero
phase shift smooth roll-off response and steep response filters are
provided, again for any mode you choose. Bandwidth is displayed as shown
in the RHS picture. Filters bandwidths (KHz) are: 0.1 - 0.2
- 0.3 - 0.4 - 0.5 - 0.6 - 0.8 - 1 - 1.2 - 1.3 - 1.5 - 1.6 - 1.8 - 1.9 -
2.1 - 2.2 - 2.4 - 2.5 - 2.7 - 2.9 - 3.1 - 3.4 - 4 - 5 - 6 - 8 - 10 |
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Pass Band Tuning (IF Shift)
The IF passband can be shifted to remove or minimise interference. In
fact, for example, in LSB the passband can be shifted to receive USB (if
you really want to). Passband may be shifted upto +/-5KHz in 10Hz steps. The passband position is represented by the
red LED bar below the green tuning aid. As the passband is moved, the
tuning aid will only show signals within the IF passband window. Passband tuning
is available in any demod mode and any bandwidth. RHS picture BL+0Hz (bottom
cutoff frequency). LHS
pictures show AM signal on the tuning aid. Bandwidth set to 6KHz and IF
filter shifted up by 1KHz. You can see this offset on the red LED bar. Normally for SSB the default lower cuttoff is BL
300Hz. |
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Tuning Aid
this is a great facility for CW, AM and data modes. A very responsive
display that is remarkably helpful. The scale/range of this bar changes
automatically when the bandwidth and or passband tuning is used, to maximise the width of the LED bar. Works for all demod modes and
bandwidths. In
operation the centre segment is red and the response of the display is
instant as you tune in across a signal. |
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RF/AF Signal Level Meter
This bar is accurate across the complete range of RF input levels
and is calibrate in dBuV EMF. RF/AF button toggles between RF and AF
measurement. |
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RF/IF Gain control
The usual slow and fast AGC modes are available. To set a threshold
gain press the SQ button. The red LED bar
below the green signal level LEDs will indicate the receivers maximum gain
threshold, above which receiver gain will be limited. Adjustment is done
using the control below Gain/Thr button. In these two pictures the
minimum signal level is set to +60dBuV. Note that the Notch filter is
also turned on and set to -2KHz below centre. |
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Tuning Rates
Three tuning rates are available; 1Hz, SLow and FAst
In SLow and FAst rates the receiver chooses the freq step size and
steps per knob rotation, depending on the bandwidth and demod mode. For
example as one would expect, in A1A(CW) narrow bandwidth, the tuning step
is reduced to 20Hz in FAst and 10Hz in SLow. RHS picture in 1Hz
tuning, showing both SL/FA LEDs off. |
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Setting & Using a Custom Frequency Tuning Step Size
Using the Scan Param button, setup a step size of your choice. Then
press the Freq Scan button and choose a tuning speed using the SL FA
button. That's it. Whenever the Freq Scan mode is on (but not running), you will be able to
tune using your custom step size. So for example, set step to 9KHz and the
steps per rev to suit and you can tune on each AM channel in the MW band.
The SL/FA key sets the number of steps per tuning knob rotation. |
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Demodulation Modes
A1A(CW) - A3E(AM) - J3E(SSB) - X3E - J7B - F3E(FM) - F7B(FSK) -
F1B(FSK)
J3E, J7B, F7B and F1B are also settable to upper or lower sideband.
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FSK Data Modes
Dedicated FSK modes are provided and may be decoded.
I have never tried these modes. |
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Channel Memories
100 channels are available to store frequency, filter bandwidth and demodulation
mode. Each channel may be set with a flag to be ignored during
scanning.
Notch, passband tuning and frequency step size are not stored. |
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Built in Test Equipment (BITE)
Test 00 is used to initiate a complete BITE test sequence.
Following successful completion of a BITE test sequence, the alpha
display shows 'BITE finished'. Individual tests may also be initiated to
check specific areas of this receiver during diagnostic or alignment
procedures. |
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