QRP 2000 USB Controlled Synthesiser Kit (Discontinued)

Developed by QRP2000-Design team:

Tom DG8SAQ, John (SK) G8BTR, Alan M0PUB, Guido PE1NNZ, Steve G0XAR & Jan G5BBL

After 14 successful years, we have taken the decision to discontinue this Kit. A factor in this decision has been the worldwide component shortage, which has seen the Si570 chips significantly rise in price and become difficult to source. This page will remain to provide information and documentation for existing kit owners.

Main Applications

    Full Band or Multi Band coverage of Softrock RXTX V6.1 and V6.2 transceivers (use Kit 1 CMOS version)

    Standalone Operation (without PC connection) with Last Frequency Remember supported (Modification required)

    External Local Oscillator for other SDR hardware Projects using PowerSDR application

    Wide range test oscillator output frequency programmable in steps < 1 Hz

Basic Specification

  • Frequency Range Kit 1: 3.5 MHz to 210 MHz for Kit 1 (10-160 Mhz specified by Silabs) and Kit 2: 3.5 MHz up to 280 MHz (10-280 MHz) specified by SiLab for C-grade LVDS device supplied) Si570BBB Device up to 945 MHz (810 MHz specified by Silabs) available

  • Stability +/- 50 ppm CMOS or +/- 20 ppm LVDS versions

  • Output: Square wave : CMOS version 2.6V pk-pk 15pF , LVDS version 0.7V pk-pk into 100 Ohm

  • Power Supply: USB Powered or +5V to +12V Power Supply  approx 100mA

  • PCB size 41 x 48 mm

  • Suitable for constructors with some previous experience of kit building experience like Softrock Projects

This Kit uses the Silicon Labs Chip SI570, an "ANY-RATE I2C PROGRAMMABLE XO", which is a 7x5mm 8 pin integrated frequency synthesizer, that can generate almost any frequency between 3.5MHz and up to 945 MHz depending on the Si570 chip used.  The ready programmed ATMEL connects to the PC via the USB port

  • Kit 1 supplied with Si570CAC -max frequency 160 MHz
  • Kit 2 supplied with Si570BBC - max frequency 280 MHz
  • Kit 3 supplied without chip
  • Kit 4 supplied with Si570BBB - max frequency 810 MHz (Discontinued)
  • Kit 5 supplied with Si57DBA - max frequency 1.417 GHz
Complete kits supplied including quality double-sided PCB, a programed Atmel ATTiny85 Micro-Controller and Si570 chip as ordered.

QRP 2000 Documentation

USB-SynthesizerAssembly Manual Latest QRP2000 v2.6 documentation as from January 2011 updated with Windows 7 and Vista Certified Driver installation information

PCB V1.1 SDR-Synthesizer Kit Documentation (PDF File) Older PCB V1.0 Build Documentation and Circuit diagram PCB

Field Bulletin for PCB V1.1 PCB error correction

AVRSi570 Troubleshooting Guide by DG8SAQ Use this guide to trace your problem

QRP 2000 Software

Download latest Digitally Certified Driver Windows 7, Vista (64 bits and32 bits) - this is the latest driver required for Windows 7 and Vista which also suitable for older Microsoft OS courtesy of Fred Krom (PE0FKO)

Current PowerSDR Software for SDR Current version of PowerSDR application with Softrock extensions provided by Guido PE1NNZ through Sourceforge

Latest PowerSDRS R40 Installation Documentation Updated PE1NNZ PowerSDR Documentation

Rocky V3.6 SDR Application Software Download Alex VE3NEA's Rocky 3.6 Program with USB AVR support  - thanks to Alex for providing this support.

Latest V4 USB_SYNTH - Stand alone application to set Si570 Frequency:

Tom DG8SAQ has written a cute application to set the frequency of theSi570 which may be downloaded from the link above.


-The frequency may be set to the nearest Hz......
-Or a Multiplication factor (in fractions) or Frequency offset (IF offset) may be specified ..
-Applications include RX Local Oscillator and VXO for TX applications, Test Oscillator or QRSS Beacon etc.
-Picture right shows the Setup screen and the configuration options.
-Last Frequency Remember - Option for Standalone applications
-SI570 Speed grade can be set for optimum use of C-grade device

QRP 2000 Articles

This Project was published in:

SPRAT 135 - Summer 2008- Journal of the G-QRP Club. 'USB-Controlled Synthesizer for Softrock RXTX and Local Oscillator Applications' by Jan Verduyn G0BBL.

FunkAmateur June 2008 Pages 622-624
'Minimalistischer hochwertiger Synthesizer mit USB-Steurung' by Thomas Baier DG8SAQ

Other Kits

R3500D ARDF Receiver Kit

R3500D ARDF Receiver Kit

£28.50 incl VAT: £34.20

Indicative prices in EURO €33,92

Indicative prices in USD $36.19