QRP Labs QCX-mini CW, Руководство по сборке, Страница: 74 / 121

First adjust the band-pass trimmer capacitor C1. To do this, give one long press to the
“Select” (left) button. The screen now displays the first menu category:
1 Preset
Turn the rotary encoder until you see the alignment menu:
8 Alignment
Now press the “Select” button, to enter the alignment menu. For example, for 17m
operation, the alignment frequency menu item should already be set to a frequency in the
CW section of 17m, as follows:
8.1 Align frq
18,120,020
Now turn the rotary encoder until you see:
8.7 Peak BPF
Press Select!
Do as it says! But if you have earphones plugged in, please take them out of your ears
first. The tone will be very loud. Press the “Select” button to switch on the signal generator
so you can adjust the C1 trimmer potentiometer. Now if you have earphones plugged in
(and lying hopefully, on your bench), you will hear a loud tone at 700Hz. The display will
look like this photograph (QCX/QCX+ i.e. blue display; on the QCX-mini, the display is
yellow):
Adjustment of the C1 trimmer capacitor should change the size of the amplitude bar. You
need to adjust the C1 trimmer for MAXIMUM amplitude. There will be TWO peaks per
rotation, since the capacitor has no stops; either peak is fine. When this is done, the peak of
the band pass filter will be centered on the CW section of the band.
It is very important to understand the number at the top right of the LCD, here shown as 09.
This is an amplitude scaling factor, expressed as a power of 2. In this example, the actual
amplitude is divided by a factor of 512 (2 to the power of 9) then displayed on the screen. In
QCX-mini assembly Rev 1.05
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