Elecraft K2 Owner's Manual - Manual (Page 145)

N o i s e B l a n k e r
S S B A d a p t e r
BFO Buffer/Attenuator
2nd Xtal Filter
Post-Mixer Amp.
RP4, RP5: 100K
K2 RF Board
Product Det.
V BIAS-XFIL
W. Burdick
Attenuator
Xmit Mixer
Rcv. Mixer
NB Bypass RF Preamp
Elecraft
E.Swartz
I.F. OUT
(Sh. 3)
1SV149
1SV149
MC1350
IF Amp
2N5109
2N5109
Buffer
LT1252
2 of 4
1N4007
1N4007
RX VFO
TX VFO
+14dB
Rev. Sht.
100µH
2.7K
2.7K
NE602
100µH
100µH
RFC11
RFC12
RFC13
4.7uH
NE602
V AGC
V BFO
MV209
TUF-1
-10dB
V ALC
Date
680
1.8K
C155
C161
C183
C185
C162
C160
C159
C141
C146
C184
C150
C167
2.7K
5.6K
C151
.001
R111
C182
18
R112
C166
R101
C173
C176
100K
C172
C177
C174
.022
C169
100K
100K
2.7K
C142
C143
.01
C145
100K
C181
100K
R107
C154
C156
C153
C158
C178
C168
J310
.01
C53
C54
C52
C55
0.1
AGC
.01
.01
.01 .01
220
R83
R80
R81
R85
150
.047
R82
.01
R76
R77
R75
.01
.01
.01
.01
R95
R96
82
R94
R93
330
R92
U10
BPF
12V
12V
100
68
100
.01
K16
K17
0.1
U12
Q21
Q22
R97
L34
180
R90 R88
R89
470
100
470
R84
X10 X11
D30 D31 D32 D33
D34 D29
RP4 RP4 RP4 RP5 RP5 RP5
.047
10K
J10
.01
0.1
220
820
U11
RP6
R100
390
D38
RP6
RP6
L33
D37
J11
.01
R73 470 R72
.01
R74
12V
RP6
.01
D39
100
.047
R91
820
R78
.01
0.1
Q24
270
R99
.01
270
R98
TP2
R8
U9
R6
R7
.01
By
X5
680
10
4.7 Ω
18
X6
820
33
V-
V+
R5
W5
33
22
8R
X7 X8 X9 W2 W3
J9
V-
V+
82
8A
X3
X4
8R
D6
D7
10 11 12
T6
47
8T
68
Z6
22
J5
1 2 3 4
5 8 6 7
1
2
3
4
5
7 6
8
3
2
6 +
-
7
4
2
4
3
9
7
8
2
4
3
9
7
8
1 2 3 2
1
2
3
4
5
6 7
8
3 4
8
7
1 2 3 4 5 6 7 8 9
1
3
2
4
1
2
1 2
3
4
G
D
S
2
C164
.01
1 2 3 4 5 6 7 8
J12
AUXBUS
8R
+7dBm
XFIL Out XFIL In
SSB Control
Aux. AF
8R
AUXBUS
8T
/DOT-PTT
MIC AF V RFDET
V XFIL2
V XFIL2
4
1
2 3
T7
C157
.047
Q20
8T
12V
2N7000
C144
100pF
D36
5082-3081
EXT ALC
C163
.01
1.8K
R79
8R
C165
.01
8A
5
6
2
1
4
3
6
5
1
2
3
4
5
6
1 3
3 1
PD2
PD1
41µH
Q12
2N7000
HI IP
C170
.047
Appendix B
4.917MHz
BFO
-5dB, Z= 150 Ω
D29-D34: 1SV149
NOTE: If Noise Blanker is installed,
R88 and R90 must be removed,
and R89 replaced with a jumper.
3.9K
R114
5.6K
R110
C186
.01
Q25
C179
100
PN2222A
4.9136 MHz Variable-Bandwidth Crystal Filter
D41
1N4148
D40
(NOTE 2)
(NOTE 1)
NOTE 1: Remove C167 when SSB Adapter is installed.
NOTE 2: D40 and D41 were added to improve handling of extremely
strong signals (from nearby transmitters). These diodes
must be soldered on the back of the PC board (see text).
1/27/04 F