Elecraft K2 Schematics Compiled by Sverre Holm, LA3ZA, from manual pages of www.elecraft.com Rev 1.0 - 18 February 2005 Contents: 1. 2. 3. 4. 5. 6. K2 Block Diagram Rev D K2 Schematic Key Rev D K2 Front Panel Board Rev C K2 Control Board Rev F K2 RF Board Rev F K2 Manual Errata Rev F-2 3 4 5 6 7 11 7. 8. KPA100 Schematics Rev G KPA100 Errata Rev C-3 12 14 9. 10. KSB2 Schematics Rev F SSB Bandwidth Modification Rev A 15 16 11. K160RX Schematics Rev A 18 12. KNB2 Schematics Rev D 19 13.
T-R BANDPASS FILTERS T-R T-R POWER AMP (15W) DRIVER LOW-PASS FILTERS AGC 4.915MHz ATTEN. AND PREAMP POSTMIXER AMP RCV MIXER NOISE BLANKER BUFFER PLL SYNTH. VCO 6 - 24MHz T-R CRYSTAL FILTERS XMIT MIXER T-R BAL. MOD. MCU AND SUPPORT CIRCUITS BFO 4.915MHz I.F. AMP PROD. DETECTOR AUDIO FILTER, AF AMP Shaft Encoder KEY Common Transmit Receive DISPLAY AND CONTROLS Appendix C BLOCK DIAGRAM W. Burdick/E. Swartz Rev.
Relay Table Diodes SET Relays MV209, 1SV149 Band BPF LPF VCO 160m 80m +60m *40m ALT 40m 30m 20m 17m 15m 12m 10m K2 K2, K3 K1, 60m-K1 K1 K1 K3, K4 K4 K5 K5, K6 K6, K7 K7 160m-K1 K8 K12 K12 K12 K9 K9 K11 K11 K10 K10 K13 K13, K13, K14 K14, K13, K13, K15 K13, K13, 1Nxxxx K14 K14 K15 K14, K15 K15 K14, K15 K15 Transistors 2N7000 2N3906 PN2222A ZVN4424 MPS5179 S E 2SC2166 2SC1969 2N5109 C J310 + 60 meters is available only if the K60XV option is installed.
15 35 BANDSTORE ANT1/2 TUNE S4 D1 MENU S5 S3 S2 S1 S0 15 S4 S5 S6 S7 BP2 BP3 BP0 BP1 S10 VLCD NB S6 EDIT D7 RATE LOCK #0 S7 LEVEL D3 D0 6 5 8 9 10 4 3 100K S0 C9 1 R16 /MIC RD /BANK2 9 10 6 5 G H 3 14 4 F E 13 D 12 C 74HC165 GND VCC R1 5K Keyer Speed /SPD RD cw ccw 8 16 /QH 7 QH 9 SER CLK 2 10 11 CLK INH SH/LD 1 5A U2 15 1 ENC A ENC B 11 B A 18 17 /Q7 SOUT GND GND 2 5A 10 16 15 /Q4 /Q5 /Q6 GND SIN SRCK 3 19 14 6
1 - 8 V SMTR RA1 RB5 IDAT I SENSE RA2 RB4 /SR RD V SENSE RA3 RB3 /SLOW AGC RA4 V POTS RA5 RB1 SR WRT RP2 ENC A RE0 RB0 SR DIN 5 1 RP3 47K 82K R12 820 RE1 VDD RE2 VSS /AGC OFF 10 EXT ALC RP4 82K RP5 470 RP4 82K 3 X2 C21 33 6 5A 15 3 C38 680 C22 8-50 2 P6 Q9 Q10 MPS5179 MPS5179 RD6 /DASH OSC1 RD5 RX OSC2 RD4 TX RC7 RC6 /MUTE RC2 RC5 SCK RC3 RC4 COUNT 100kHz-40MHz VSS RC1 /DAC2CS 20 /PLLCS RD0 RD3 RD1 RD2 /DOT-PTT 25 P7 3 0-25.
PLL Reference Oscillator PLL Synthesizer RFC15 12.090-12.100 MHz 12.096MHz X1 Q19 8B TP3 100 µH D 1 G X2 12µH S (NOTE 1) C84 120 2 4 4 RP2 D16 MV209 7 SCK 8 3 RFC14 18µH D17 10K REFOUT PH R PDOUT DIN 6 /PLLCS PH V FIN 5 SDO C87 .01 C85 120 10K 1 3 R22 3.3M OSCOUT VSS /ENB LD CLK FV DOUT FR C91 .001 (NOTE 3) 1 2 SDO 27K 15 R24 13 12 C88 68 10 - 5 2.7K 2.7K 11 6 4 R30 7 + C92 .
C165 8R 12V C52 .01 R72 470 R73 2.7K K16 C142 .01 .01 R82 C160 .01 C143 .01 9 2 C141 .01 9 2 C53 .01 RFC12 100µH R78 22 RX VFO 18 Noise Blanker C158 +7dBm R74 47 7 4 7 4 J12 8 3 8 3 .01 K17 R81 1.8K C159 .01 4 RFC11 100µH C163 .01 1 2 3 4 5 6 7 R7 68 R6 100 1 Z6 C145 .01 T6 R8 4 100 1 12V 2 C161 .01 3 TUF-1 R75 680 -10dB 2.7K R80 Buffer 680 R83 4.7Ω R79 1.8K W5 NB Bypass R84 18 100 R88 470 R90 470 +14dB C162 C164 .01 C146 .
J15 60m 4 C5 100 3 C4 820 2 2 L2 40/60m L5 C12 560 K2A 20m/ 160m 4 30m/80m 5 G 6 7 8 X 8T K3 1 C108 .01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 R65 10K 16 RXRY RY COM P6 Aux. RF 160RY 2 1 C224 .047 8T RFC2 100µH 9 C114 1N4007 D3 K2B L4 4.7µH A n t. 8R 6V 8 .01 D4 4 W1 D2 C110 .01 1N4007 W6 R39 1K R37 100K D5 RFC3 47µH RX Ant. Bypass 80m L16 K8A 7 3 L3 4.
12V RFC4 10µH + C119 .01 C126 47µF C133 0.1 R45 47 C135 .01 Z1 C127 T2 RFC5 12:8, FT37-43 10µH Q7 3 LPF C122 C115 .01 680 2SC1969 2 56 R53 4.7Ω 4 1 RFC8 10µH R55 33 (Sh. 3) C129 .01 5 C A 6 1 3 R58 2 4 1/2W T3 3 C116 33 8T C120 .01 C121 .01 2 R49 120 1 RFC6 RFC9 10µH D C130 0.1 B 180 8 0.68µH 4 Q8 7 T4 2:3:1:1 2SC1969 T1 9:3, FT37-43 R44 2.7K C128 680 Q6 2SC2166 R40 C118 470 .01 R48 120 Z2 R47 47 R50 + (Sh.
K2 KI T CHAN GES AN D MANU AL ERR ATA R e v . F - 2, F e b . 26 , 2 0 0 4 PL EAS E READ TH IS INF ORM ATI ON BEFOR E YOU BEG IN ASS EMBLY Your K2 kit includes a number of recent upgrades to both hardware and firmware. These include: Modified CW keying envelope to significantly reduce transmit bandwidth Limiting diodes on the receive I.F.
TP2 N:111 12PA J1 R14 180K RF IN 5R 1W K1 C76 RFC5 100µH .015 5T 200V C72 .01 1 GND RFC11 100µH .01 RFC3 100µH D12 1N4007 C73 .01 C71 .0018 200V C31 .033 200V C75 0.1 100µH 5µH C59 C67 R39 T44-2 L15 .033 C81 4700 22 0.1 3W 5µH C82 (not used) T4-6 C1 30pF GND RFC1 T4 FT50-43 C79 .039 200V L16 200V T4-5 D14 1N4007 RFC4 RFC10 100µH LPF OUT 100µH T-R Switch 1N4007 LPF IN K2 (SHEET 2) D11 C86 .
K1 U3 78L05 IN 12CTRL 5V OUT MCU C23 0.1 1 C25 .001 VFWD RA0 RB6 TP1 VREFL RA1 RB5 5 nc C26 33 10 X2 4 MHz C27 30pF RP1 5 RA3 RB3 RA4 RB2 RA5 RB1 VSS RB0 OSC1 VDD or ULN2803 7 1 2 3 4 5 6 20 RC7 SCALE RC1 RC6 5R RC2 RC5 RC3 RC4 12PA SENSE 6 RB4 VSS 14 TD62083 3.9K C29 C22 .01 .01 7 5V 8 9 IN0 /OUT0 IN1 /OUT1 IN2 /OUT2 IN3 /OUT3 IN4 /OUT4 IN5 /OUT5 IN6 /OUT6 IN7 /OUT7 GND COM C12 .01 18 C13 .01 C2A S.M. C24 .
K2/100 MANUAL (Appendix G) ERRATA Rev. C-3, December 14, 2004 PLEASE READ BEFORE YOU BEGIN ASSEMBLY Important Notice Your KPA100 kit includes recent circuit changes that allow the K2/100 to handle higher mismatch conditions, allowing power reduction to start at an SWR of 2:1 rather than 1.5:1. Since your kit is one of the first shipped with these enhancements, it may include an unused toroid core, a few extra resistors, and an extra capacitor (the previous component values). Errata Items 1.
P2 P3 PLASTIC DIP (DUAL-INLINE PACKAGE) 1 2 PN2222A 3 D10-D14 1 2 3 4 1N4007 E C1 78L06 OUT GND I N C B 3 = On bottom of PC board. D6-D9 C7 100µH CLOCKWISE (8-PIN DIP SHOWN) 100µH C17 .01 6 D10 RXS RP1 7 4 2.7K 2 C3 8 D11 C4 0.1 5 3 D6 8 C2 .01 1 C13 0.1 C6 .01 C10 .01 7 RP2 5 2 2.7K 4 C9 100 R11 150 CD (short) CA 39 SSB CJ CF 100 CL 100 CP 39 (short) T2 3 2 C35 X2 X1 3 1 .01 D8 C11 .01 4 C5 .01 3 .
Elecraft SSB B/W Modification (SSBCAPKT) Installation Instructions Revision A, November 9, 2004. Copyright © 2004, Elecraft; All Rights Reserved Parts Inventory P/N E530016 E530049 E530141 E530144 E530152 Description 100 pF, 100V,5%,NPO,0.1LS, CAP 150 pF,100V,5%,NPO,0.2LS, CAP 27 pF, 200V,5%,NPO, 0.1LS, CAP 33 pF, 50V, 5%, NPO, .1LS, CAP 39 pF, 50V, 5%, NPO, .
The wider bandwidth filters require that the BFO be tuned to a higher frequency for receiving USB on the lower bands. For the 2.4 kHz bandwidth, the BFO must be able to reach approximately 4916.5 kHz and for the 2.6 kHz bandwidth it must reach approximately 4916.8 kHz. Be sure and check your maximum BFO frequency before attempting to use a wider filter bandwidth. To measure BFO frequency, attach your K2 frequency probe to TP2 and use CAL FCTR to read the BFO frequency.
K160RX Schematic 160m Low-pass Filter Receive Antenna Relay L1 2 9 K2 3 8 4 L2 C1 C2 C3 1500 2700 1500 7 2 9 3 8 RX 4 K1 7 GND RX ANT. K2 K1 (Note 1) 1 10 1 10 C4 C5 RY COMMON 1 2 3 4 .001 160 RY RX RY C6 .001 .001 5 6 7 8 9 10 11 12 13 14 15 16 J1 To RF Board, P12 NOTES: 1. Remove RF board jumper W1 before using a separate receive antenna. Refer to manual for Elecraft operating instructions. By W. Burdick 2.
Circuit Details U1 amplifies the I.F. signal, which is then detected by D2 (1N34A). Q1 reduces the gain of U1 in proportion to overall signal strength, keeping the signal at D2 relatively constant. Negative-going pulses that are above the threshold established by D3 and R3 turn Q2 on, triggering the one-shot (Q3/Q4). Q6 can be used to switch in a larger-value capacitor, increasing the blanking time.
7.
Circuit Details, KAT2 L-C Board The L-C board provides eight series inductors and eight parallel capacitors, configured as an L-network. The capacitance can be placed at the transmitter or antenna end of the network via a relay on the Control board (see next page). Each inductor and capacitor has its own DPDT relay, with the individual sections of each relay placed in parallel for reliability. The relays are selected under control of the ATU's microcontroller.
Circuit Details, KAT2 Control Board T1, D1, D2 (etc.) form a directional coupler for SWR and power measurements. This type of bridge is much more accurate than the K2's standard RF detector (D9) in the presence of non-50-ohm loads. The bridge output is buffered by op-amp U4 and routed to the K2 control board, overriding the signal from D9. The bridge outputs are also connected to A-to-D inputs on the microcontroller, U1.
L1 .08µH L2 .16µH L3 L4 .64 µH .32µH L5 1.3 µH L6 2.6 µH 4 4 L7 5.2 µH L8 10.4 µH L OUT L IN 4 4 1 4 1 4 1 3 1 3 K1 1 3 1 3 K3 K2 1 3 K5 4 1 3 K4 4 3 K6 3 K7 K8 C 3 4 3 4 1 K3 K2 K4 4 3 K11 1 K1 3 K10 K9 C4 82 C3 39 C2 22 4 K6 K7 3 K12 4 3 1 K18 (Sheet 2) C30 0.1 C14 C15 3 C11 C16 C10 C17 K10 K9 3 4 K16 1 K11 K13 K12 K15 K14 C29 0.1 K16 2 C9 0.1 2 5 C18 0.1 C22 C23 C21 C24 C20 C25 C26 C19 0.1 C54 0.1 0.
J5 Antenna 1 RFIN T1 FT50-43 SWR Bridge 4 P1 ANT1 L OUT (Sheet 1) K17 1 Ant. Switch P7 R1 3.3K R2 GND 4 1 C (Sheet 1) C32 100 4 3 2 L IN 2 3 1 * 1 2 (Sheet 1) * J4 RF IN 1 C31 30pF J6 Antenna 2 3 W1-W2: Both open = Auto. LED control; W1 = DOT; W2 = BAR JUMPERS K18 W3-W7: Leave open except as required (see manual). 200 1W W1 W2 FPDATA 21 RD3 2 RD1 RD0 RC3 20 RC2 RC1 RC0 OSC2 15 OSC1 VDD 10 RE2 RE1 RE0 RA5 4 3 4 R8 3.
LED 5A Brightness R115 220 Control 4.0V DAY (18mA/LED) PN2222A 2.7V NIGHT (6mA/LED) (based on LED Vf=1.9V) D113 R113 120 D114 Q102 R116 470 C102 .047 R114 120 /NIGHT 18 16 HP SOUT /Q6 R112 120 YELLOW LP GND GND 11 R111 120 D112 GREEN 10 4 17 /Q7 19 14 15 5 3 SIN GND /Q0 /Q1 SRCK /SRCLR / Q 4 8 7 5.0 D111 R110 120 13 /Q5 RCK 6 VCC /G 9 2 4.0 D110 R109 120 12 /Q3 /Q2 SOUT GND 5 18 /Q5 GND 3.
L2-L4: 100 µH C3-C6: .01 µF -6 TO -12 V L2 1 C8 D1 10 µF 1N4148 D2 1N4148 + J1 To PC D1-D4 D3 2 TXD 5 VCC 6 VDD R1OUT T1IN R1IN T1OUT R2OUT T2IN R3OUT R2IN T2OUT R3IN 7 1 2 3 4 5 12V C9 Q1 D4 1N4148 MAX1406 .001 J310 C10 120 D D S G U1 C1 Q1 .01 16 15 14 13 12 11 9 AUX 10 15µH T3IN L1 T3OUT RF 12V GND C4 VSS L4 C5 C6 6 C3 7 L3 8 4 3 RXD 8 C 1N4148 ALC 9 A S X1 L5 16.289 MHz 8R C11 .01 FT23-43 C14 R1 56 3.
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R17 6V Reg. U4 OUT GND Z1 4 MHz + GND R14 2.7K IN OUT 1N5711 BT1 3V - Note 2 10µF 12V C11 .01 W2 C10 IN D2 1N5711 + 78L06 78L06 D1 5.5V 220 W1 6 7 5 CE CLK 8 VDD GND U3 4 /XT 3 XT 2 1 I/O RB3 RB2 9 RB1 NJU6355ED 8 7 6 RB0 VSS 5 DATA 11 12 13 14 15 10 RB4 RB5 RB6 RB7 VDD 16 RA4 3 RA3 RA2 2 1 J309 MCLR 16C621A U2 R16 AUXBUS OSC2 18 0.
K60XV Schematic OUT P2 1 (J15) 2 R9 10K C6 4.7 K1A RFC2 15µH K1B 7 8 9 470 K2A 4 C2 8-50 * R8 2 C7 .01 XVTR T-R C11 .01 7 6 8-50 C4 47 C3 47 4 D2 D1 5082-3081 5082-3081 7 C1 4 3 BPF 5 2.2 3 C8 .01 TX IN 3 C5 2 6T 8R 1 4 2 3 1 TX RF 2N3906 P1 To XVTR I/O (J13) 2 Q1 3 IN J1 XVTR RF 6V To 40/60m BPF 8 8 60 m 6V K2B C9 .01 9 R7 470 K1 and K2 are DPDT latching relays shown in RESET position. Pins 5 and 6 of the relays are not connected internally.
K60XV MANUAL ERRATA Rev. A-3, June 8, 2004 PLEASE MAKE THE FOLLO WING CHANGES TO TH E MANUAL BEF ORE PRO CEDING TO ENSURE THAT TH E K60XV FUNCTIONS CORRECTLY Page 13: Delete the third assembly step from the bottom, which begins “Switch to 40 meters….” Page 16: At the end of the first paragraph, add the sentence: “Leave D 1 9 set for PA 6 0 =4 0 , even when using KPA100 kit revision C.” (See detailed information below.) IMPORTANT OPERATING NOTES: 1.