Elecraft KXB3080 - Manual (Page 14)

14
REL
A
Y
Re
v A
Elecraft
LPF1
+ 1
K1
- Bare Ground Wire Connects
Here and Extends from this
(Relay) Side of the PCB
The ground wire goes to the + pad as shown.
The + and - marks were printed on the PCB
incorrectly during fabrication.
Figure 10. LPF1 Ground Wire Connection.
Cut two 9” (23 cm) lengths of the green toroid wire and two 13” (33 cm) lengths of the larger #26 red
toroid wire.
Wind L1 and L2 on the remaining T37-2 (red) toroid cores as shown in Figure 11. Note that each core
has two separate windings: one with 9 turns of green toroid wire and one with 15 turns of red toroid wire.
Be sure the direction and orientation of the windings are exactly as shown. Although L1 and L2 are actually
identical, they are shown oriented as they will be mounted on the LPF1 PCB.
After winding, cut all leads to at least 1” (2.5 cm), then strip and tin each lead from the end up to the
point described below:
L1-1: Where the lead leaves the front edge of the core in Figure 11.
L1-2: Where the wire exits the center of the core.
L1-3: About 1/8” (3 mm) from where the wire leaves the front edge of the core in the figure.
L1-4: Where the lead leaves the back edge of the core in the figure.
L2-1: About 1/8” (3 mm) from where the wire leaves the back edge of the core in the figure.
L2-2: About 1/8” (3 mm) from where the wire leaves the front edge of the core in the figure.
L2-3: Where the wire exits the center of the core.
L2-4: About 1/8” (3 mm) from where the wire leaves the front edge of the core in the figure.
4
4
9 Turns
Green
15 Turns
Red
3
3
1
1
L1 L2
2 2
9 Turns
Green
L2 L1
4 4
2 2
3 3 C1
Toroids Oriented
For Mounting on PCB
LPF1 PCB
Toroid Side
Figure 11. LPF1 Toroid Inductors L1 and L2.