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AA7 • 10
• SOLDER ALL wires or pins of the part, whether the 2 wires of a
resistor or the 3 or 4 wires of a transistor.
• Trim or Nip all excess wires extending beyond each solder connection,
taking care that wire trimmings do not become lodged in PC-board
solder connections.
Soldering the AA7 Printed Circuit Board
1. Install J1, the RF input jack. Notice that it is connected directly to the
screw hole for the extendable whip antenna. Solder all 4 points of the
jack secure!
2. Install S1, one of the two push switches. Position it so that the
plunger of the switch extends over the edge of the PC board. It fits
correctly only one way and is on the same side of the board as J1, which
you have already installed. Notice that this switch selects which
preamplifier circuit will be used. We'll wire the VHF circuit path first,
because it's a little easier. Solder all six points of the switch.
3. Install C3, 100 pf. immediately behind S1.
4. Install R6 100K [brown-black-yellow] next to C3. NOTE: Save the
extra wires nipped away from C3, R6 and similar parts. You will use
them to make jumper wires.
5. Notice that Q2, the 2SC2498 transistor is installed with the flat side
facing the rear (antenna and receiver jacks) of the PC-board. Press the
transistor gently but firmly into it three holes so that the exposed wire
leads are as short as possible. Carefully solder all three leads on Q2.
6. Using a scrap component lead wire, install jumper wire 2 (JMP2) near
S1. This connects the preamp that is selected by S1 to the coupling
capacitor for the receiver jack.
7. Similarly, install JMP1. (This connects the J2 receiver jack directly to
J1 and the whip antenna when S2 is in the out or off position.
8. Install R4, 100 ohms [brown-black-brown].
9. Install C6, .01 µF. which couples the output of the selected
preamplifier path to the J2 receiver jack.
10. Install C2, .01 µF. When S1 is in the "out" or HF position, C2
couples the RF input to the Dual gate MOSFET preamplifier you are
about to build.
11. Install R1, 1 megohm [brown-black-green].
12. Install R2, 220K ohms [red-red-yellow].
13. Install C1, .01 µF.