Software Defined Radio

With USB interface

Published in issue 365, May 2007

SD (software-defined) radio receivers use a bare minimum of hardware, relying instead on their software capabilities. This SDR project demonstrates what’s achievable, in this case a multi-purpose receiver covering all bands from 150 kHz to 30 MHz. It’s been optimised for receiving DRM and AM broadcasts but is also suitable for listening in to the world of amateur transmissions.

Resistors
R1,R7,R19 = 100Ω
R2,R3 = 330Ω
R4 = 100Ω
R5,R8,R13,R17,R20 = 100kΩ
R6,R10,R14,R22 = 10kΩ
R9,R21 = 4kΩ7
R11,R23 = 27kΩ
R12,R15,R18 = 470Ω
R16 = 1MΩ
R24 = 1kΩ
R25 = 4Ω7
Capacitors
C1,C2,C5,C6,C7,C10,C11,C16,C17,C19,C20,C21,C25-C28,C30,C32,C33,C34,C36,C38,C39,C40 = 100nF
C3,C4,C9,C15 = 4µF7 16V radial
C8,C18 = 10nF
C12,C13 = 10pF
C14 = 470µF 16V radial
C22,C24,C35,C37 = 2nF2
C29 = 220pF
C31 = 100pF
Semiconductors
IC1 = 74AC74
IC2,IC7 = 74HC4066
IC3 = CY27EE16 (Cypress)
IC4 = FT232R (FTDI)
IC5 = TL084CN with socket (see text)
IC6 = 74HC4051
T1 = BF245
Inductors
L1-L4 = 10µH
L5 = 47µH
L6 = 2.2mH
Miscellaneous
K1 = USB-B socket, PCB mount
K2 = stereo jack socket, 3.5mm, PCB mount
K3 = 2-way PCB terminal block, lead pitch 5mm
PC1 = solder pin
X1 = 10MHz quartz crystal
Ready-populated and tested PCB, order code 070039-91
Project software, free download 070039-11
Supplementary document, free download
PCB, bare, ref. 070039-1 from www.thepcbshop.com