Ramsey Electronics AA7 - Manual (Page 11)

AA7 • 11
ˆ 14. Install R3, 100K [brown-black-yellow].
ˆ 15. If you have completed Steps 4 through 14 correctly, you now have
the 4 holes for Q1 surrounded by other parts, making it easy to find!
Examine Q1, the dual-gate MOSFET. The schematic diagram shows
why it has 4 leads. Insert Q1 so that the square tab is pointing directly at
JMP2, but... DO NOT solder Q1's 4 leads until you are satisfied that the
tab is oriented as explained, and that the 4 wires are in the respective
holes without any twisting. Just as for Q2, keep Q1`s wires as short as
possible. Solder all four leads of Q1.
ˆ 16. Insert RF gain control R5 into the PC board, make sure it is seated
securely. Solder the three pins and the two mounting tabs.
ˆ 17. Install C5, .01 µF.
ˆ 18. Install C4, the polarized electrolytic capacitor. Electrolytic capacitors
have polarity and must be installed properly. The negative side of the
capacitor is marked with a black stripe with negative sides. The PC
board or the parts layout diagram will show the correctly labeled (+) sign
next to the positive hole. Be sure to use the correct polarity.
ˆ 19. Install S2, which controls DC power and also connects the antenna
jack, J1, and the receiver jack, J2, directly together when in the turned
“off” position. Solder all six points of the switch.
ˆ 20. Install receiver jack J2. Solder all four points of the jack.
ˆ 21. Install the battery snap connector (WITHOUT the battery for now,
please). Make sure the positive (red) and negative (black) wires are
connected in the correct holes. This PC board follows the accepted
standard that the red wire denotes the positive hole (+) and the black
wire denotes the negative (-) hole.
ˆ 22. Install the battery hold-down clamp using a scrap component lead
wire placed through the two holes in the clamp and into the PC-board
holes. Pull the wire tight and then solder it firmly to the two PC-board
points and to the clamp itself (on the top side of the PC board.) Be sure
not to use too much solder on the clamp as it may keep the battery from
sitting flat and securely in the clamp.
ˆ 23. Using the mounting screw supplied, attach the whip antenna to its
position on the PC-board. The whip antenna should point up from the
component (top) side with the screw inserted through the bottom.
Tighten it firmly to ensure a good electrical connection, don’t force it so
hard that you break it or the PC board and it’s delicate traces. You may
wish to lightly sand the plating from the screw head and solder it to the
PC-Board.