Rev: November 20 2006
14
Ferrit caps of L4 and L5 should be about 1-2 mm below the copper shield.
Now switch on your BCR. Go to Menu, Setup and into the ZF section. The
default frequency stored by us is 1kHz below the Xtal frequency, that is the
normal value for this type of ladder filters. Because there is no Xtal filter
built in, the absolute frequency is not very important in this moment. In
the headphones you should hear a signal now. The frequency depends on the
trimmer C29. You may have a look at the AGC Voltage: connect a Voltmeter
to the upper end of R14 and ground. Range 0-2 V. Switch off the DDS in the
Menue. Adjust Trimpot P5 to abt 0,2V. Now again switch on the DDS:
Menue, Setup, ZF. The voltage at R14 should increase. You may adjust L4/
L5 now for maximum reading, but the final adjustment will be done later on
after the Ladder filter has been installed.
Switch off your BCR and remove the link wire. Go ahead with section 5
Group 5 DDS Signal preparation,
Mixer, IF buffer and Ladder Filter
[ ] C48 1000pF (102)
E-3
[ ] C47 10nF (103)
E-3
[ ] R33 1M upright
E-2/3
[ ] R36 100R upright
E-3
[ ] R34 47k upright
E-3
[ ] R35 1K upright
E-3
[ ] C49 100nF (104)
E-3
Attention, place the notch of the socket to the right side as shown in the
picture .
[ ] DIL 14 socket
D/E-3
Dont install the IC now, this will be done if the sectrion has been
completed!
[ ] Dr1 100
u
H SMCC
C/D-2/4
[ ] C13 47nF (473)
C-4
[ ] Dr2 100
u
H SMCC
C-4
[ ] C3 47nF (473)
D-4
[ ] C4 100nF (104)
E-4
Take care for the notch!
[ ] DIL 14 socket
D/E-3/4, do not
install the IC itself!
[ ] C9 47nF (473)
D/E-4
[ ] R4 1K uppright
E- 4
[ ] R5 82R upright
D/E-4
Remember: The Quartz must be
installed a little bit above the PCB!
[ ] Q1 4,915MHz HC49U
D-4/5
[ ] Q2 4,915MHz HC49U
D-5
[ ] Q3 4,915MHz HC49U
D-5
[ ] Remove the help wires you used to install the Xtals!
Left and right next to the Quatzfilter there are holes to connect the
enclosures of the Xtals to ground. Use a piece of wire and solder it between
ground connection points and quartz housings. Solder at half the height of
Содержание Blue Cool Radio
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