Appendix b, Power amplifier (pa), Pre-driver – Elecraft K2 Owner's Manual User Manual
Page 147: Pa bias, Driver
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Power Amplifier (PA)
12:8, FT37-43
9:3, FT37-43
K2 RF Board
PRE-DRIVER
Pre-Driver
W. Burdick
Elecraft
E.Swartz
2SC2166 or 2SC5739
(Sh. 3)
(Sh. 3)
2SC1969
2SC1969
PA Bias
PN2222A
PN2222A
2N5109
Driver
4 of 4
100µF
0.68µH
Rev.
Sht.
4.7
Ω
470
C117
C115
C133
1.5
Ω
C119
C126
47µF
RFC5
10µH
1/2W
C127
C128
C129
C137
C122
RFC4
10µH
C124
RFC6
C120
C130
C121
C138
4.7K
C116
Date
0.047
.01
270
560
22
Ω
R55
R56
R53
R54
12V
R42
R41
R43
R47
R46
R40
R45
R50
.01
4.7
Ω
4.7
Ω
0.1
R58
180
680
680
.01
56
0.1
R49
120
.01
0.1
.01
Q11
Q13
R59
R61
R62
.047
2.7K
120
33
47
Q7
Q8
Q5
Q6
Z1
Z2
47
33
33
T1
T2
8T
By
3
4
1
2
3
4
1
2
+
+
C125
22µF
RFC8
10µH
RFC9
10µH
8
3
4
1
5
6
7
2
T4
LPF
C135
.01
Q10
2N7000
V BIAS-XFIL
8T
C118
.01
2.7K
R44
C131
0.1
8T
2:3:1:1
G
S
D
R48
120
+
R63
220
/CLASS AB
C
A
D
B
T3
Appendix B
BETTER EFFICIENCY AT 5W
NOTE: WIND T4 2:2:1:1 FOR
(SEE "MODIFICATIONS" SECTION)
1/2 W
100
R60
1/27/04
F
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