FlexRadio Systems FLEX-1500 Manuel utilisateur
Revision 1.0
1
Copyright FlexRadio Systems, 2010-2011
FlexRadio Systems
FLEX-1500
Software Defined Radio
Service Manual
Author: raham Haddock, KE9H
Revision 1.0
2
Copyright FlexRadio Systems, 2010-2011
Contents
Introduction ..... 3
Theory of Operation .. 4
Alignment, Test and alibration.... 11
Troubleshooting and Diagnostics ....... 14
Assembly and Disassembly....... 15
Fuse Replacement... 16
Appendix “A” Schematic, PTRX (Transceiver) Board
Appendix “B” Schematic, PPA05 (RFPA) Board
Appendix “ ” Boards, Top View.
Appendix “D” Test Points and Bus Access.
Appendix “E” Test Fixtures.
Appendix “F” Parts List.
Revision 1.0
3
Copyright FlexRadio Systems, 2010-2011
Introduction
The FLEX-1500™ QRP Software Defined Radio is an entry eve QRP radio and is a so
suited to be the idea IF deck for VHF-Microwave operation. It provides a of the
advantages of a software defined radio, inc uding the sophisticated high performance
fi ters, panoramic spectrum disp ays and computer based graphic interface characteristic
of a software defined radio.
This service manua assumes that the reader / service technician is fami iar with the
operation of the radio and PowerSDR contro software. If additiona information is
required on those topics, p ease refer to the Product Manua and Quick Start Guide.
Front View - FLEX-1500
Revision 1.0
4
Copyright FlexRadio Systems, 2010-2011
Theory of Operation
Refer to the B ock Diagrams on the two fo owing pages.
The detai ed schematic are inc uded in Appendix “A” and Appendix “B”.
The unit is powered by +13.8 Vo ts DC, supp ied via the 2.5 mm x 5.5 mm coaxia power
connector on the rear of the unit. The unit has an interna 3.0 Ampere fuse that wi b ow
if the unit draws excessive current or if the po arity of the power connected to the unit is
reversed.
The FLEX-1500 CPU (TAS1020B Streaming USB Contro er) wi communicate via
USB for both contro and streaming baseband data with the host CPU running the
PowerSDR software. The CPU in the FLEX-1500 has contro of a switching, signa
routing, frequency generation via the DDS, F exWire port, audio amp ifier, as we as
audio and baseband routing, CODEC c ock generation, data conversion, gain and eve
contro s for the radio.
Communication between the F ex-1500 radio and the host computer is via a USB
connection capab e of USB 1.1 or higher eve USB operation. The protoco is USB
“Fu Speed” or 12 Megabits per second data transfer rate.
Power Systems and Distribution
The transceiver board requires a source of regu ated +5 Vo ts at approximate y 400 mA
to function. +3.3 Vo ts is supp ied to the board in genera by a inear +3.3Vo t regu ator
derived from the +5 Vo t ine. Additiona +3.3 Vo t and +1.8 Vo ts required to operate
some of the integrated circuits is provided by point-of- oad regu ators in the vicinity of
the IC.
Overa power for the unit is derived from the +13.8 Vo t input on the RFPA board.
This 13.8 Vo ts direct y supp ies the re ays and power amp ifier transistors. It is a so
feeds two regu ators. A 6 Vo t regu ator is switched on when transmitting, and off when
receiving. This switched +6 Vo t output is used to bias the RF power transistors. A
separate +5 Vo t regu ator supp ies power for the SPI decoder and re ay driver IC on the
RFPA board, as we as supp ies a +5 Vo t power to the transceiver board (PTRX) via
the board to board interconnect system.
Revision 1.0
5
Copyright FlexRadio Systems, 2010-2011
Revision 1.0
6
Copyright FlexRadio Systems, 2010-2011
Revision 1.0
7
Copyright FlexRadio Systems, 2010-2011
ontrol Busses
There are severa contro busses that interconnect the radio. A USB “Fu Speed” bus
interconnects the host computer running PowerSDR with the on-board CPU, the
TAS1020B. Contro from the TAS1020B CPU to the rest of the radio and externa
contro is via an I2C bus system, and two SPI busses.
Firmware for the CPU is resident in a oca (I2C) EEPROM on the transceiver board.
Upon power up, the CPU wi ook for the presence of a proper y programmed EEPROM,
oad this code, begin execution, and register with the host computer as a FLEX-1500
device. In the absence of the EEPROM, or ack of correct y identified firmware, the CPU
wi execute from interna ROM, and identify itse f to the host computer as a “TI DFU
device.”
The FLEX-1500 CPU wi communicate via USB for both contro and streaming
baseband data with the host CPU running the PowerSDR software. The CPU in the
FLEX-1500 has contro of a switching, signa routing, frequency generation via the
DDS, F exWire port, audio amp ifier, as we as audio and baseband routing, CODEC
c ock generation, data conversion, gain and eve contro s for the radio. A of the above
must be trans ated from oca hardware and register contro s to the Command and Data
structures chosen for USB transport and interface in the host to the PowerSDR software.
I2C Bus
The I2C bus exists as three instances.
(1.) The computer bus (I2C-C), which contains the (master) CPU, the EEPROM
containing program memory and ca ibration parameters, and the Bus Mux.
(2.) The Interna I2C bus, (I2C-I) containing the two bus expanders and the
CODEC chip.
(3.) The Externa I2C bus (I2C-E) which is routed to the F exWire DB-9
connector, and is on y used in conjunction with an externa F exWire device.
The I2C Bus Mux se ects whether the Computer I2C bus wi be connected to the Interna
or Externa I2C bus extension at any given time, as we as passing any interrupt requests
upwards to the CPU. Since the EEPROM and the Bus Mux are on the computer bus, their
addresses wi appear in a I2C bus spaces.
I2C Bus Structure
The I2C bus address va ues are provided according to the TI convention, where the
address is an eight bit word, expressed as two hexadecima characters. The east
Revision 1.0
8
Copyright FlexRadio Systems, 2010-2011
significant bit is actua y the ~read/write bit, but is a ways presented as a “0” when the
address is expressed. The TAS1020B is the I2C Bus Master and is a ways connected to
the I2C Mu tip ex Chip and the EEPROM.
When the Bus Mux is set to “Outside,” the I2C bus is routed to the appropriate pins on
the F exWire connector. When set to “Inside” the I2C bus is routed to the CODEC, and
the two Bus Expanders, which convert I2C commands to many high/ ow outputs used to
contro the individua switches that contro signa routing in the radio.
The Audio Amp ifier is contro ed by genera purpose outputs from the CODEC.
SPI Bus
There is a so a SPI bus, used to contro the DDS and the RFPA. It appears as two
physica instances, a 3.3V version and a 5V version. The SPI is outbound contro on y,
for both the AD9951 DDS and RF PA board.
The AD9951 DDS is contro ed via the 3.3 Vo t SPI bus, direct y from the CPU.
The DDS can be programmed to operate with either a 20 MHz or 38.4 MHz reference
input. The 20 MHz signa comes from doub ing the externa 10 MHz input, and the 38.4
MHz is generated by an onboard temperature compensated crysta osci ator.
The TPIC6B595 Re ay Driver is contro ed by the 5 Vo t SPI bus, and contro s the
fo owing re ays according to the band of operation or transmit/receive status.
A “High” SPI contro bit is the active state, which provides a LOW output from the re ay
driver to turn the re ays ON.
I.C. Name
Bit
Pin
Name
Function
Initial
Drain0 0 4 15M Active = 17 or 15 Meter Band 0 = Inactive
Drain1 1 5 160M Active = 160 Meter Band 0 = Inactive
Drain2 2 6 20M Active = 30 or 20 Meter Band 0 = Inactive
Drain3 3 7 6M Active = 6 Meter Band 0 = Inactive
Drain4 4 14 80M Active = 80 Meter Band 0 = Inactive
Drain5 5 15 10M Active = 12 or 10 Meter Band 0 = Inactive
Drain6 6 16 XMIT HIGH = Trans it ode, LOW = Receive ode 0 = Receive
Drain7 7 17 40M Active = 60 or 40 Meter Band 0 = Inactive
RF Signal Processing
The incoming RF signa s may be received via the antenna connector on the RFPA board,
the transverter receive connector, or the transverter common connector. These signa s are
routed via the appropriate bandpass fi ter, then either direct y to the preamp, or through a
Revision 1.0
9
Copyright FlexRadio Systems, 2010-2011
20 dB pad to offset the gain of the preamp. The output of the preamp is fed to the QSD
down-mixer, with an output of I and Q baseband signa s in the range of 0 to 24 kHz.
The QSD down-mixer is a so supp ied with a quadrature oca osci ator signa which is
derived from the DDS. The DDS operates at twice the desired oca osci ator signa ,
passes though a 120 MHz ow pass fi ter, into a Johnson Counter that both divides the
DDS frequency by two, as we as generates the two quadrature oca osci ator signa s.
In transmit, in a reverse manner, I-Q baseband signa s from the CODEC in the baseband
range of 0 to 24 kHz are supp ied to the QSE, a ong with the quadrature oca osci ator
signa s at the operating frequency, resu ting in a direct QSE output on the fina transmit
frequency, which is routed via the bandpass fi ters to either the transverter output
connector, or the input to the RFPA.
Baseband Processing
In the receive direction, output I and Q signa s from the QSD are passed through a set of
OpAmps that have 18 dB of signa gain and 28 kHz ow pass fi ters, then sent to the
CODEC for digitization and transmission to the host computer.
In transmit, ana og I and Q signa s output from the CODEC are fi tered in a 26 kHz ow
pass fi ter to remove wideband digita noise, then sent to the QSE for up-mixing.
ommunications
In the receive configuration, digitized I and Q signa s from the CODEC, representing the
received pass band, are transferred using the I2S protoco to the Streaming USB
contro er. This contro er then transfers this information via the USB protoco to the
host computer. Processed and demodu ated audio is returned via the USB protoco to the
contro er, then transferred to the CODEC via I2S protoco for conversion into ana og
audio signa s.
In transmit configuration, digitized microphone audio signa s from the CODEC are
transferred using the I2S protoco to the Streaming USB contro er. This contro er then
transfers this information via the USB protoco to the host computer. Processed transmit
audio in a digita I and Q format is returned via the USB protoco to the contro er, then
transferred to the CODEC via I2S protoco for conversion into ana og baseband signa s to
drive the QSE up-mixer.
In the BITE (Bui t In Test Equipment) configuration, digitized I and Q signa s from the
CODEC, representing the received pass band, are transferred using the I2S protoco to
the Streaming USB contro er. This contro er then transfers this information via the
USB protoco to the host computer. Transmit test signa s in a digita I and Q format are
Revision 1.0
10
Copyright FlexRadio Systems, 2010-2011
sent via the USB protoco to the contro er, then transferred to the CODEC via I2S
protoco for conversion into ana og baseband signa s to drive the QSE up-mixer.
Audio Amplifier
An audio amp ifier is present, capab e of driving stereo headphones, or stereo powered
speakers, in the Stereo configuration, or a monophonic speaker direct y, in the Mono
configuration. In stereo, each of the two amp ifiers are carrying the appropriate eft or
right channe information, and driving a ow power amp ifier suitab e for headphones or
high impedance oads. In the Mono configuration, the two incoming stereo signa s are
mixed together to form a sing e mono signa . This is fed to one amp ifier direct y and
inverted and fed to the other amp ifier to form an “H-Bridge” speaker amp ifier. In this
mode the speaker must be wired to bridge the amp ifier output (connect to tip and ring on
stereo speaker p ug) with no connection to ground.
Autres manuels pour FLEX-1500
2
Table des matières
Autres manuels FlexRadio Systems Radio
