Elecraft K1 - Manual (Page 78)

Crystal Filter
Receive Mixer
Noise Blanker
K1 RF Board
Int. Speaker
Appendix B
W. Burdick
Attenuator
Headphones,
4.915 MHz
XFIL/TONE
XFIL/TONE
LM2930T-8
To FIL-P1
E.Swartz
RCV RF
LM380N-8
/AGC OFF
1 of 2
1N4148
1SV149
ZR78L06C
1SV149
Premix
AF Amp
BYPASS
MPSA14
SA602
SA602
SA602
100K
100K
MV209
220µF
220µF
10µF
2.2µF
0.01
6A 6A
6R/AUX
J 3 0 9
.047
3 3 0 0
1 2 0 0
100K
RFC1
1 2 0 0
680
100K
10µF
.047
1.5 Ω
C67
2.2µF
C66
C39
2 2 0
C38
2 2 0
C61
.047
C27
C26
C24
R16 R18
R17
C23
4:20, FT37-43
.01
C21
R14
RP1 RP1 RP1
C37
.01
C63
C65
3 3 0
C20
C19
C5
C41
RP2
VFO
D17
3 9
.047
7 5
1 2 0
7 5
2.7K
.01
.001
RP1
33 µH
R7
C40
.01
C25
.01
RP2
6 8
RP2
OUT
GND
4.4 µH
.01
C35
OUT
GND
5:20, FT37-43
3 9
C30
GND
IN1
IN2
GND
OUT
C33
12V
C31
AGC
R1
X3
U2
X1 X4 X2
V -
V+
U1
V -
V+
U7
V -
V+
T1
K1
D6 D7 D8
2 2
X5
5 0
1 0 1 1 1 2
P 1
1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0
Q8
C12
J 2
P 2
J 1
C11
3 9
C7
C6
L 1
D4
C2
D3
IN
U6
IN
U5
T2
J 6 C10
V+
NC
U4
C9
1.8K
1
2
3
4
5
6 7
8
1
2
3
4
5
6 7
8
1
2
3
4
5
6 7
8
3
4
2
4
3
9
7
8
1
2
3
4
5
6
1 2 3 4 5 6 7 8 9
3
4
G
D
S
1 2
7 8
1 2 3 4 5 6 7 8
7
8
1
2
+
3
4
1 2 3 4 5 6 7 8
R23
+
1
2
3
4
5
6
7
8
+
+
Q2
+
Low-Dropout
8V Regulator 6V Reg.
2 2 0
C42
/AGC OFF
1 2
J 9
1 2
J 1 0
Premix
PREMIX
To Rcv Mixer (via W1)
.01
C4
12V
R6
2.7K
POWER
RF/SMTR
6B
VFO POT
To FP-J1
VFO POT 6B
1
2
AGC (1.2VDC, no signal)
OFFSET
6B
1
2
PD2
PD1
-14 dB
Product Det./BFO
+
47K
RP3
Q1 6R/AUX
2N7000
RF/SMTR
C74 C72
C70
C71
C17
C18
RP3
3 4
RP3
2 1
.01 .01
PD1
PD2
Q9
8 2
C8
KEYIN
R5
2.7K
2N3906
47K 47K
1 0
9
.01
.01
S
D
G
0.1
0.1
COUNTER
6R/AUX
*
the noise blanker is installed
RFC6
6A
6T 6R/AUX
Buffer
Q3
2N4124
C22
.001
RP6
4
3
27K
RP6 5 6
RP6
27K
2
1
C36
.01
D2
1N5711
100K
RP2
5
6
NOT USED
C32
.047
BYPASS IN1
IN2
OUT GND
V+
G1 G2
1
2
3
4
5
6
7
8
U3
LM386N-1
Ext. Speaker
AF2 AF1
C69
220pF
RP3
6 5
47K
J 3 0 9
Q11
G
S
D
8V
8V
C54
2.2µF
R21
2.7K
XFIL/TONE
D1
1N4148
RP3
7 8
47K
6B
6R/AUX
R13 2.2M
AF1 AF2
C64
.01
(no signal)
+
AF Preamp/Mute
Q10
2N7000
S
D
G
1.0VDC
3.080 MHz when RF = XX.000 MHz
2.930 MHz when RF = XX.150 MHz
R2
6T
100K
100µH
R3
8.25K
C73
0.1
C34
0.1
1 0
R15
* *
1 %
C68
0.1
Elecraft
Rev. Sht. Date By
G
RFC9
10 µH
Use 120 pF at C2 for ~150 kHz range **
C22 must be removed when *
12V_2
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