1. High Performance IF and Transverter Design
Or how I learned to love Dynamic Range…
Eric Swartz
WA6HHQ
Hands on Ham Radio.

2. The K2/100 CW/SSB HF Transceiver

3. XV Transverters for 50, 144 and 222 MHz

4. High Performance K2 Transceiver Sensitive: -136 to -138 dBM MDS
Wide Dynamic Range: +21 dBM IP3
Quiet IF
XV Transverters
Sensitive: 0.8 dB NF
Wide Dynamic Range: +20 dBM IP3
Built in TX Keying Sequencing (20, 50, 200 mS)
Work with the K2 and most HF Rigs

5. XV 144 NF Plot (143 – 147 MHz)

6. IF Rig Design Parameters
Single Versus Multi Conversion
Are more conversions better?
Why go to double or triple conversion?
General Coverage RX
Cascadable filters

7. Multi versus Single Conversion
Multi Conversion
More IF stages + Wide first roofing filter = Easier Overload, More Noise
Multiple IF Filters
Single conversion
Fewer Stages = less noise and distortion
Immediate conversion to 1st IF narrow filter
Better close in dynamic range
DSP cascaded after crystal filters

8. Design Parameters Phase Noise
Phase noise measures the off frequency sideband energy of your local oscillator.
Excessive phase noise:
Limits Sensitivity and Dynamic Range by mixing off frequency signals on to your IF frequency
Transmits broadband noise
Crystal Osc. vs Linear VFO vs PLL vs DDS

9. PC-1600a Phase Noise

10. K2 Phase Noise

11. Design Parameters Receiver Gain Distribution
Sensitivity vs Dynamic Range
Maximize Dynamic Range at your needed sensitivity.
Balance Transverter NF and Gain with IF rig’s
Too much front end gain limits dynamic range!

12. IMD Dynamic Range
Inter-modulation between multiple off frequency signals producing interfering distortion products inside the receive IF bandwidth.
Test Methods: 20 kHz, 5 kHz spacing
Swept IMD Test

13. Dynamic Range vs MDS

15. Blocking Dynamic Range
De-sensing of RX by off freq. signals
Impacted by RX front end design.
Impacted by PLL Phase Noise
Test Methods: 20 kHz, 5 kHz spacing
Swept Blocking D.R. Test

16. IC-706 Swept Blocking Dynamic Range

17. K2 Swept Blocking Dynamic Range

18. System Design Parameters
A great XV can’t fix a poor IF rig!
XV and IF both need wide dynamic range
IF rig needs good close in performance
Use only as much XV gain as needed
Too much front end gain KILLS dynamic range
A better IF rig NF needs less XV gain
Balance NF and system gain with dynamic range

19. In-Band Audio IMD
Audio Distortion from multiple RX signals inside narrow IF filters.
Receiver ‘Mush Factor’ in pile-ups
Impacted by:
AGC (Fast, Slow, Too much, Where applied in the RX chain)
RX Filter Shape and group delay
Product detector artifacts
Audio amplifier distortion

20. Mark V FT1000MP In-Band Audio IMD

21. K2 In-Band Audio IMD

22. K2: Basics = Great RX Performance
Focus on the Basics
Single Conversion: Simpler -is- better
Strong Front End
Narrow Bandpass Front End Filters
Strong Mixer, Post Mixer Amp.
Clean PLL VCO (Band Switched)
Optimal Gain Distribution; AGC Level
IF AGC + DSP after the Xtal Filter
Clean Audio Chain

23. XV Series Transverters
Stackable on the same IF bus
+17 dBM Mixer for dynamic range
PHEMT front end; <= .8 db NF
50, 144 and 222 MHz - Stackable
Use with K2 and Most Other Rigs
Built in TX Sequencing up to 200 mS

26. K2 Block Diagram