Welcome to the SDR-Kits USB Synthesizer Kit

Updated 2nd July 2014

QRP2000 USB-Controlled Synthesizer - Now available with Si570BBB000141DG covering up to 810 MHz as specified by
Silicon Labs -
In practice the Si570BBB can be used up to 945 MHz. -

Scroll down for Pricing and Ordering information

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

Download latest Digitally Certified Driver Windows 7, Vista (64 bits and 32 bits) - This is the latest driver required for Windows 7 and Vista which also suitable for older Microsoft OS courtesy of Fred Krom (PE0FKO)    Link to PE0FKO website - additional advice on driver installation.

Download original Windows XP USB-Synthesizer Driver and Firmware - This is older driver for Windows XP, ME, 2000 and Windows 98 OS.

Download the USB-Synthesizer AVR Trouble Shooting Guide

Developed by QRP2000-Design team: Tom - DG8SAQ, John (SK)- G8BTR, Alan - M0PUB, Guido - PE1NNZ, Steve - G0XAR & Jan - G0BBL

Fig 1: Top view of USB Synthesizer PCB

This Kit uses the Silicon Labs Chip SI570, an "ANY-RATE I2C PROGRAMMABLE XO", which is a 7x5mm² 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 Si570CAC CMOS version is specified for 160 MHz, max freq 210 MHz, , The Si570BBC LVDS version is specified up to 280 MHz and the Si570BBB LDS version is specified at 810 MHz with 945 MHz as maximum. The Si570 chips are programmable via an I2C Interface.
The ready programmed ATMEL connects to the PC via the USB port.

Main Applications

Basic Specification:

Fig 2 : Component Placing - U2 Si570 is mounted at the other side of the PCB

Kits & Parts Pricing - Webshop Ordering Link

Complete Kits contain a quality double sided PCB, a programmed Atmel ATTiny85 micro-controller and other parts including the SiLabs Si570CAC000141DG CMOS device, Si570BBC000141DG or Si570BBB000141DG will be supplied as ordered.

QRP2000 USB-controlled Synthesizer Documentation and Applications

USB-Synthesizer Kit Assembly Instructions (PDF File) for current v2.06, and older 2.05, v2.04 & v2.03 PCBs

Older PCB V1.0 Build Documentation and Circuit diagram PCB can be downloaded here:

PCB V1.1 SDR-Synthesizer Kit Documentation (PDF File)

Field Bulletin for PCB V1.1 PCB error correction.

PowerSDR Software Release
Current version of PowerSDR application with Softrock extensions provided by Guido PE1NNZ through Sourceforge can be downloaded here.
Current PowerSDR Software for SDR

Updated PE1NNZ PowerSDR Documentation can be downloaded from here:

Latest PowerSDRSR40 Installation Documentation

USB - AVR Troubleshooting Guide – Use this guide to trace your problem.

AVR Si570 Troubleshooting Guide by DG8SAQ


Latest V4 USB_SYNTH - Stand alone application to set Si570 Frequency

·         Tom DG8SAQ has written a cute application to set the frequency of the Si570 which may be downloaded from the link above.

Links -

USB AVR Project Home page of Tom Baier DG8SAQ.
Tom developed the AVR firmware for this project and also had a big input into the hardware design of the AVR-Synthesizer. The LATEST Released AVR firmware may be downloaded from Tom’s website:

PowerSDR SDR Software: This is the link to download the freeware version of PowerSDR which supports the USB-Synthesizer produced by Guido PE1NNZ and Alan M0PUB & others who provided this great software

Rocky V3.6 SDR Application Software:

Use this link to download Alex VE3NEA Rocky 3.6 Program with USB AVR support
Thanks to Alex for providing this Support!!

Publications -

This Project was published in:


Copyright notice:          The USB-Synthesizer project design on this page is Copyright 2008, 2009, 2010 and 2011 by  QRP2000 Design team.All rights reserved.  
Kit of parts produced by under licence from QRP2000 Design Team

Website Copyright 2008, 2009, 2010 and 2011 by