SDR Cube Transceiver

Online Assembly Guide

Detailed construction notes for building and testing each of the SDR Cube kit modules

    Home  Bill of Materials    I/O Board    Controls Board    DSP Board      Softrock SR-Base     Softrock TX/PA  
RXAMP  Multi-Rx  X-LPF    Internal Cable Set    External Cable Set 
Start Here for Quick Kits ==>    Main Enclosure    Digital Subassembly Test    Final Assembly    RF Functional Test   


Building the Softrock RXTX Base Board (SR-Base)  

What Is It?

The SDR Cube is designed to interface to any quadrature-based RF front end that provides I/Q baseband audio signals. We use the terms “RF front end” and “RF deck” to mean the electronics that perform the mixing, amplification and filtering of RF signals for an HF radio.  The most popular and prolific RF deck around is the Softrock family of small and inexpensive kits.  Some 11,000 of these boards in different flavors have been sold around the world already, and each depends on a PC for signal processing and user interface.  So by designing the SDR Cube to easily interface with this huge installed base of Softrocks, we provide a way for every Softrock owner to decouple from the complexities of using the PC as a radio, while simultaneously tapping into a ready-made market without needing first to design the RF deck ourselves. 







Version C13

Designator QTY Description
C1, C8 2 1000pF ceramic
C2, C4, C6, C9, C11, C13, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C31 19 10uF 16v
C3, C10 2 100pF ceramic
C5, C7, C12, C14 4 0.022uF ceramic
C27 1 0.033uF ceramic
C30, C34 2 0.01uF ceramic
C35 1 4.7uF ceramic
C32, C33 2 4.7uF ceramic
C36, C37 2 0.047uF ceramic
C38, C39 2 CAP CER 4700PF 50V C0G RAD
C40, C41, C42, C43, C44, C45, C46, C47,C48, C49, C50, C51, C55, C60, C62, C63, C64, C65 18 0.1uF 1206 SMT
C52, C53, C54, C56 4 0.01uf 1206 SMT
C57, C58, C59, C61 4 0.01uf 1206 SMT
D1, D2 2 1N4003
J1 1 4 pin, SIP sockets
J2 1 5 pin, SIP sockets
J3 1 2 pin, SIP sockets
J4 1 3 pin, SIP sockets
Q1, Q3, Q4 3 2N3904
Q2 1 2N3906
Q7, Q8 2 BS170
P2 1 2 pin, SIP pinheader, R/A
P3, P4 2 2 pin, SIP pinheager
P5, P6, P7 3 3 pin, SIP pinheader
R1, R2, R4, R5, R7, R8, R10, R11 8 10.0k, 1%
R19, R20, R25, R44, R45, R48 6 10.0k, 1%
R3, R6, R9, R12, R18, R17 6 49.9, 1%
R13, R14, R16, R22 4 2.21k, 1%
R15 1 3.32k, 1%
R23 1 22.1, 1%
R24 1 22.1k, 1%
R27 1 22.1k, 1%
R51, R52 2 1.00k, 1%
R46, R47, R49, R50 4 10.0, 1%
R55, R56 2 100, 1/6 W
R28 1 221, 1%
R21, R29, R30, R53, R54 5 4.99k 1%
R26 1 4.99K, 1%
U1, U2 2 TLV2462
U3, U10 2 FST3253
U4 1 LM7805
U5 1 LP2992AIMS-3.3V
U9 1 74AC74
U11 1 LT6221
U7 1 Si570
RFC-1 1 BN-43-2402, 4T, #26
  1 Wire, #26, 6"
  1 PCB
Standoffs 4 Spacer, AL, hex tapped, #4, 1/4" (PCB)
Screws 8 Machine screw, pan slotted, #4-40x3/16"



Board Layout





Go to the official Softrock RXTX 6.3 Construction web pages by WB5RVZ and build your SR-base by following those instructions ...

(Remember that not all parts shown on that RXTX 6.3 assembly page are used ... only install the parts shown above, as supplied in the SR-Base Kit.





Power and Signal Connectors for the Completed SR-Base Board




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Page last updated:  Sept 9 2014