Elecraft K2 Owner's Manual - Manual (Page 143)

Note: Current sense resistor
8V Low-Dropout Reg.
K2 Control Board
Voltmeter Input
Quad, 8-bit DAC
To RF Board, J7 To RF Board, J8
To RF Board, J6
Current Sense
Voltage Sense
8V Switching
100kHz-40MHz
V BIAS-XFIL
V BIAS-XFIL
(0.1V res.)
W. Burdick
LMC6482AIN
0.00-5.10A
Freq. Ctr
E. Swartz
LM2930T-8
/SLOW AGC
1.78k, 1%
5.1K
Elecraft
4.000MHz
5.068MHz
LM380N-8
/AGC OFF
SIDETONE
806K, 1%
196K, 1%
SR DOUT
/DAC2CS
5V Reg.
MPS5179 MPS5179
5V FCTR
V SENSE
I SENSE
PN2222A
0-25.5V
V RFDET
SR DOUT /DAC2CS
SR WRT
MAX534
SR DIN
LMC660
V POTS
/PLLCS
/SR RD
/SR RD SR DIN
1N4148
BYPASS
AF Amp
AF OUT
2N3906
2N3906
1N4148
AUXBUS
12V IN
2N7000
SR WRT
V POTS 12V IN AUXBUS
AF OUT
/PLLCS
AF OUT
LMC660
V SMTR
V SMTR
1 of 1
Rev. Sht.
/LDAC
SR CK
V BFO
ENC B
/MUTE
/DASH
.0027
2.2µF
NE602
LM833
/DAC1CS
220µF
220µF
100µF
78M05
ENC A
COUNT
SR CK ENC B V BFO
ENC A V ALC
/DASH
/MUTE
V ALC
V PWR
V PWR
Input
Date
OUTB
OUTA
/CLR
DOUT
SCLK
DGND
AGND
OUTD
OUTC
8-50
U10D
82K
U10C
47K 82K
U10B
ICLK
IDAT
/DOT-PTT
.001
22µF
2.7 Ω
0 Ω 0 Ω
J310 J310
VOL1
VOL2
.022
Mute
3.9K
3.9K
22µF
82K 82K
ICLK
IDAT
VOL1
VOL2 /DOT-PTT
.001
U10A
47K
.01
.001
REF
UPO
PDE
/CS
DIN
VDD
C21
C22
.01
RP2
RP3
RP2
PD2
PD1
RP3
47K
RP3
47K
.01
C35
C36
C33
12V
U2B
330
C10
.01
.01
3.3M
33K
U2A
.047
SCK
SDO
SCK
.047 C29
C30
GND IN1 IN2
GND OUT
C32
C26
0.1
C25
0.1
R20
R18
R19
C27
C28
R16 12V
C23
.01
R17 3.3M
RP1
RP1
RP7
33K
C15
C13
12V
.047
C19
OUT
GND
OUT
GND
.01
C37
C38
RP5 RP5
RP4 RP4
C39
.01
.01
680
470
PD2 PD1
12V
.047
C16
U3B
R10
U3A
100
.01
C17
.047
C14
SCK
SDO
5.1K
AGC
12V
2.2µF
C11
RP3
RP6
5.1K
C31
C34
5A
5A
5A
By
10
11
12
13
14
15
16
U8
X2
5A
C41
33
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
P2
10
11
12
13
14
15
16
17
18
19
20
P3
12
13
14
11
5A
8A
10
C7
C9
C8
U1
V-
V+
nc
X1
39
8A
C2
R2
D1
R5
8A
C6
v+
NC
U9
Q7 Q6
10
Q1
8T
Q2
8R
Q3
Q4
TX
RX
D2
P1
IN
U5
IN
U4
5A
C3
Q9 Q10
470
P6
J1
R9
R8
R7
1%
P5
Q11
8A
8R 8T
6
J2
8A 5A
5A 8A
RP6
RP6
8A
C1
1
2
3
4
5
6
7
8 9
1
2
3
4
5
6
7
8
9 1
2
3
4
5
6
7
8
9
+
-
4
9
8
+
-
5
6
7 +
-
+
1
2
3
4
5
6 7
8
6
5
7
+
- 3
2
1 +
-
8
4
1 2 3 4
5 6 7 8
+
+
G
D
S
G
D
S
+
1
1 2 3 4 5 6
2
1
+ +
2 1
1
2
1 2 3 4 5
5
6
7 +
-
2
3
1 -
+
8
4
4 3 2
5 6 7 8
3 4 5
8 7 9 10
5 6
1 2 3
3
2 1
+
-
2 1
1 2
RP5
470
C40 .01
RX
TX
R.F. GAIN
I.F. OUT
8R
is R115 on the RF board.
RXD
V AGC
82K
RP4
5 6
82K
RP4
8 7
5A
10
1 2
3 4
5 6
7 8
9
P4
Aux I/O
12V
8T RXD .0027
C12
R6
100
AUXBUS
AUXBUS
/AGC OFF
A u d i o
F i l t e r
270K R21
82K RP2
4 3
ALC
EXT ALC
V RFDET
EXT ALC
PN2222A
Q8
8A C18 .01
C20
.001
8R
C5 .01
3 4
4
3
5
6
/EECS
7
8
V SENSE
I SENSE
47K RP3
8 7
+ -
10
9
4 3
5 6
Q12
PN2222A
8R 8T
TXD
RP7
33K
3
4
C24
.0027
10K
R3
8R
5.1K
RP6
1 2
/SLOW AGC
0.47µF
C4
+
5A
5A
RP7
33K
5A
Q5
RP7
33K
5 6
2N7000
TONEVOL
MCLR
OSC1
OSC2
RA4
RC0
RC1
RA0
RA1
RA2
RA3
RA5
RE0
RE1
RE2
VDD
VSS
RC2
RC3
RD0
RD1 RD2
RD3
RC4
RC5
RD4
RD5
RD6
RD7
VSS
VDD
RB0
RB1
RB2
RB3
RB4
RB5
RB6
RB7
RC6
RC7
10
15
20 21
25
30
35
40 1
5
U6
8
7
Appendix B
18C452
MCU
3.9K
RP1
9
10
5.6K
R4
/HOLD
/CS
/WP
VSS
SCK
VCC
SDO
SDI
1
2
3
4 5
6
7
8
U7
25LC320
EEPROM
0.1
C42
RP5
470
9
10
(NOTE 1)
TXD
.001
C43
P7
1 2 3
INT EXT
Voltmeter Source
5.1K
RP6
8
7
R1
50K
AGC THR.
ccw
cw
820 R12
R11
47K
VOL3
VOL3
L1
82 mH
= on bottom of PC board NOTE 1: Jumpers are used at R18 and R19. They must be removed if the Audio Filter option is installed.
(.02 A resolution)
Not Used
C44
82K R22
22µF
C45
+
("D3" on PCB) .01 C46
*
*
Part of CW key shaping *
mod; solder on back (see text)
1/27/04 F