Embed Size (px)
Citation preview
Kit Building Revisited - the Elecraft Way
QCWA Chapter 70 September 18, 2007
Bob MacKenzie VA3RKM
Mike Babineau VE3WMB
Martin Gillen VA3SIE
Eric, WA6HHQ Wayne, N6KR
Who Are We? Both hams since ‘71 Wayne (N6KR, ex WN6HQH)
– QRP Design Fanatic (Sierra, NorCal40, SST…)– B.S. Cognitive Science, UCSD– Silicon Valley Guy (Firmware / EE / UI)
Eric (WA6HHQ)
– Kamikaze QRP DX’er (NorCal40 DXCC)– B. S. Electronics, Yale – Startup Addict: Mountain Comp., Verisys, Elecraft
Goals….. Re-birth of the ‘Heathkit’ Experience
Building and using your rig is Fun! (‘Mojo’)
Create a worldwide community of Elecraft builders to share their experiences.
Encourage portable HF operation. Bring back the excitement of building, modifying,
(breaking), fixing and operating with equipment you have built yourself!
Comprehensive Assembly Manual You'll find the manual easy to follow, with step-by-step assembly, clear illustrations and photos, and modular checkout of each major section. There's also a detailed theory of operation section, as well as a complete troubleshooting guide.
Strong Customer Support Our technical support via telephone and the Internet will get your Elecraft up and running quickly. On-line manuals, frequently asked questions (FAQ), application notes and our user group e-mail list make building a great experience.
(14mHz, 500kHz filter)
Blocking Dynamic Range5kHz (de-sense)
Inter- modulationDistortion 5kHz(IMD)
Phase noise Receive CurrentDraw
ElecraftK2 135 dB 91 -124 150-200 ma
YaesuIC 7800 115 89 -120 110V
TenTecOrion 130 92 -138 3.1 A
YaesuFT1000MP 119 83 -118 2.8 A
YaesuFT897 96 67 -102 900 ma
IcomIC 706 II 86 74 -118 2 A
Good or excellent score 120 to 130 dB 89 -120
K1 Four or Two-Band HF Transceiver
K1 – Cover Off
K1 – Side View (Panels Removed)
KAT1 ATU Mounted above K1 Filter Board
The K2 CW/SSB HF Transceiver
K2 Advanced Features CW Full Break-in; Diode Switched TX/RX
Programmable Memory Keyer (9 memories)
‘Hunt and Pounce’ Band Search Mode
120ma Low Current RX Mode
Built in Test: Freq. Counter, Volt/Amp Meters
Self Calibration Firmware
The K2 Transceiver Key Fundamentals:
– Good RX Performance– No wires construction; Modular,
upgradeable Down conversion to low IF (4.915MHz)
– Best trade-off of cost / complexity– IF derived AGC, Variable B/W CW
crystal filter
K2 SSB Option 160M / 2nd Ant Option
Audio Filter/Real time Clock
K2 Block Diagram
LOW-PASS FILTERS
POWER AMP
(10W)
BAND-PASS
FILTERS
T-R CRYSTAL FILTERS
EleCraft K2 MAIN PCB BLOCK DIAGRAM
W. Burdick/E. Swartz Rev. A 11-30-97
ATTEN. AND
PREAMP
RCV MIXER
1ST I.F. AMP
RX ANT. SWITCH
ANT.
BUFFER
DRIVER
XMIT MIXER
2ND I.F. AMPT-RT-R
NOISE BLANKER
AGC
BAL. MOD.
VCOSYNTH.
T-RT-R
Option
BFO
PROD. DETECTOR
MIC AF
AF OUT
Common Transmit ReceiveKEY
12VRX ANT.
I.F. OUT
ON/OFF
Connector
12V DC
Aims:
Portability
Economy
Low current drain
Pride
High performance
Performance features and trade-offs
Where does noise come from? - many parts, many circuits (artefacts, birdies, etc.)- reduce parts and circuits and reduce noise, current drain
(1)Single-band design using latching relays- ham-bands only, SSB, RTTY and CW (160-10m)
(2)Single-conversion- tuning direction reversed above 17m
(3)Sleep-mode when possible, periodic table updating- not as responsive
(4) Simplified circuitry: No IF shift
Builder and owner assistance
Built-in test equipmentRF probe, DC voltage probe, frequency counter
Alignment and calibration featuresSelf-calibrating PLL, calibrate oscillator by WWV, align by
ear, measure power by DMM voltage, align SSB balance by S-meter, align filters by Spectrogram audio software
Owner SupportLoyal, large and savvy User’s GroupBuilders for hireAdvice and service from factory
