Transcript High Performance Receiver Design

Inside the K3
High Performance Rig Design
Dynamic Range is your friend!
Hands on Ham Radio.
© 2009 Elecraft, Inc.
The K3 HF Transceiver
K3 – What’s New?
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High performance 1st IF Filters down to 200 Hz @8.215 MHz
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IF Shift / Pass Band Tuning
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High Performance Noise Blankers: H/W and DSP– Both Adjustable
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8 Band Parametric TX & RX Equalizers
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PSK, RTTY, CW Decode. (Send data modes from CW paddle!)
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General Coverage RX BPF Option
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High Performance ATU w/2 ANTs - Matches 10:1 SWR
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100% Remote Controllable; Built-in isolated sound card interface
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K3 MCU & DSP Software Upgrades via the Internet (or local files)
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Up to 9 Transverter Bands with correct frequency display.
K3 – RX performance
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Hybrid SDR / Analog Design
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High Q front end band-pass filters
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Switching Mixer = Better Dynamic Range
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Low Noise Synthesizer (L.O.)
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Dual Diversity RX = More signals heard.
K3 High Performance Sub-Receiver
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Fully independent High-Performance RX
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Independent Synthesizer, NB, filters etc
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Split off of main RX path or from a 2nd Antenna
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3 modes of operation:
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Sub RX = VFO B (VFO B = TX if running split)
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Linked: Sub, VFO B, Tracks VFO A (with or without offset)
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Dual Diversity: True phase locked RX from two antennas at once.
Dual Diversity RX
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Two identical, phase locked Receivers.
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Use different antennas (TX ant, beverage etc.)
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Tune both together with main VFO knob
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RX1 in left ear, RX2 in right ear.
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Different signal arrival angles and directions.
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Fades at different times in each RX = less fills.
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Pile-ups / QRM spread out spatially. Use your brain to
pick out signals by their L-R location. (+3 to 6 dB)
P3 DSP Panadapter for the K3
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High Resolution Color Real-Time Spectrum Display
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Fast Spectrum and Waterfall Displays (+ Split Screen)
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Plug and Play with the K3 – No PC S/W Problems!
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Full Integration with K3 – Panadapter Tracks Main/Sub VFOs,
Point and Click Tuning etc.
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Software Downloadable for future options.
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Ships by end of this year (2009)
P3 - DSP Panadapter for the K3
P3 in Full Spectrum Display Mode
P3 - DSP Panadapter for the K3
P3 in Split Waterfall / Spectrum Display Mode
IMD Dynamic Range and Blocking Dynamic Range
5 kHz Signal Spacing
Rig
BDR
IMDDR3
Elecraft K3
140
104
Ten-Tec Orion II ($5K)
136
96
ICOM IC-7800
127
96
ICOM IC-7600 (Sherwood LabTest)
126
78 (2 kHz)
Flex-5000C
($4.8K)
123
96
Yaesu FT-9000
($10K+)
119
98
Ten-Tec Omni 6+
119
86
Flex-3000
112
96
Yaesu FT-2000
108
85
ICOM IC-756 Pro III
101
77
Kenwood TS-570D
87
72
($10K+)
RED numbers indicate >10 dB worse than K3
Blocking Dynamic Range
“De-sense”
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De-sensing of RX by off freq. signals
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Impacted by RX front end design.
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Impacted by PLL Phase Noise
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Test Methods: 20, 5, 2 kHz spacing
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K3 BDR = 140 dB+
IMD Dynamic Range
“Intermod”
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Inter-modulation between strong multiple off frequency
signals produces distortion products inside the receive IF
bandwidth.
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Dynamic Range = IMD Signal Level - MDS
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K3 IMDDR3 = 104 dB
Dynamic Range
Subject:
Date:
From:
K3 testing
Sat, 09 Feb 2008
Rob Sherwood <[email protected]>
Dear Eric and Wayne,
The high side and low side IMD is very well behaved, and virtually identical. Good job.
3rd order intermod dynamic range @ spacings:
100 kHz
20 kHz
5 kHz,
2 kHz
500/500 filtering: 104 dB
500/500 filtering: 104 dB
500/500 filtering: 102 dB
200/200 filtering: 101 dB
It looks like you are top dog now!
Better than the Orion II, the Flex 5000A and certainly better than the IC-7800.
AGC Performance
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DSP AGC impulse rejection = Smooth RX
Subject: K3
Date: Sat, 09 Feb 2008
From: Rob Sherwood [email protected]
..the K3 passes the ‘Sherwood AGC test’ with flying
colors.
1 V. P-P very fast rise time pulse, 1 PPS, is basically
ignored by the AGC
I think it is better than all the other rigs that have
come out in the last few years which fail miserably:
FTDX-9000, FT-2000, Orion II, Omni-VII, IC-7000, IC7800.
Phase Noise
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Phase noise = the off frequency sideband energy of your
local oscillator (VFO) in RX and TX.
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High Phase Noise:
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Limits Sensitivity and Dynamic Range by mixing off frequency signals
on to your IF frequency. Limits Blocking DR.
Transmits broadband noise across all of the band.
The K3’s Receive and TX Phase noise is -140 dBc at 10 kHz, 150+ dBc at wider spacings. 15-25 dB lower than ‘pure’ SDR
transceiver TX and RX phase noise.
K3: The Basics = Great RX Performance
Strong Front End Design
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Hi-Performance Switching Mixer, Post Mixer Amp.
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Narrow Band-pass Front End Filters
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Low Phase Noise (Low noise LO)
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Optimal Gain Distribution; AGC Design
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High Performance Crystal Filters
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True Dual Diversity RX opens up a new dimension.
VP6DX
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All K3 DXpedition to Ducie Island (Pitcairn)
New records for number of stations worked.
2 K3s on all bands simultaneously (CW/SSB)