QRPKits DC40A, Руководство пользователя

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2/14/2007 Page - 12
Group 3: Oscillator:
NOTE:
The 2N7000s are mosfets and can be damaged by static.
Those who live in dry areas and prone to static problems need
to take precautions before handling. This can simply be to
touch a large metal object to discharge your self, before
handling the parts.
C34: The flat side of the trimmer goes towards the line on
layout diagram. C41 not used in 40M version.
S1: You may want to mount the switch on the bottom of the
board. If you are going to mount the rig into an Altoids tin, you
won't have to open the lid to access the switch. If you mount
the rig into some other kind of enclosure, using a separate
push button or mounting the switch on the bottom may be the
only practical way of accessing it.
Crystal Socket: If you want to change frequencies, you may
want to install a SIPP socket at location X1. An example of
preparation and installation of the SIPP socket can be found at
http://www.qrpkits.com/buildertip03.html.
Smoke Test:
Connect a paddle and headphones to the board. Connect a
test lead antenna to your “big rig” and select the band for
which this kit is being built. Tune the receiver to the crystal
frequency. Place the test lead antenna near the board. Apply
power. Tune the receiver around a little until you hear the
board’s crystal oscillator. Click and hold closed the switch until
you hear the letter “T” in the headphones. The keyer is now in
Tune mode. Tapping the DASH paddle will put the rig into
transmit mode. It will remain so until you tap the DOT paddle.
You can continue to toggle back and forth between transmit
and receive using the DOT and DASH paddles. To exit tune
mode, click the switch again.
Now you can set the C34 trimmer for the proper T/R
oscillator shift. With the board in receive mode, note the
frequency of the oscillator. Toggle the board into transmit
mode and adjust the C34 trimmer so the oscillator is now 600
Hz higher in frequency than it was when in receive mode. You
can also make this adjustment with a frequency counter if you
have one. The right hand side of R12, located just below U3, is
a convenient place to connect a counter.
location value markings √
R18 10 ohms BRN/BLK/BLK
R25 51 ohms GRN/BRN/BLK
R24 100 ohms BRN/BLK/BRN
R22 470 ohms YEL/VIO/BRN
R20 10 K BRN/BLK/ORG
R23 10 K BRN/BLK/ORG
R17 15 K BRN/GRN/ORG
R19 15 K BRN/GRN/ORG
R21 22 K RED/RED/ORG
R16 100 K BRN/BLK/YEL
C31 See page 5 Band Specific
C33 See page 5 Band Specific
C32 100 p 101 DISK
C41 See page 5 Band Specific
C27 .1 uF 104 Mono
C40 .01 uF 103 Mono
C34 40p Yellow trimmer
C35 4.7 uF/16V Alum Electro
Q1 PN2222A NPN
Q3 2N3904 NPN
Q2 2N7000 mosfet
Q4 2N7000 Mosfet
Q5 2N7000 mosfet
Q6 2N7000 mosfet
D10 1N4148 diode
X1 Crystal Band Specific
S1 TACT PB SWITCH