Difference between pages "VFO-003" and "QRP Labs High Performance SDR Receiver"

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[[fILE:VFO-003-B.png]]
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[[file:QRP-Labs_P1956-720px.jpg]]
 
 
[[fILE:P771-720px.jpg]]
 
  
 
== Features ==
 
== Features ==
  
Software controlled VFO
+
* Three modules
 
+
** [http://qrp-labs.com/receiver QRP Labs High Performance Receiver Module]
* Arduino Pro Mini Microprocessor
+
*** Direct Conversion Receiver
** 8-bit ATMEGA328 CPU
+
*** Uses a Quadrature Sampling Detector (QSD), also known as a Tayloe Detector
** 8 MHz
+
*** [https://www.onsemi.com/pdf/datasheet/fst3253-d.pdf FST3253] Mixer is arranged as a double-balanced mixer for maximum performance
** 3.3V I/O
+
*** Circuit to mute receiver during transmit
* Detachable Rotary Encoder/OLED card
+
*** [https://www.ti.com/lit/ds/symlink/lm4562.pdf Low noise LM4562 op-amps] are used in instrumentation amplifier configuration to provide excellent common mode noise rejection
** SSD1306 OLED Display
+
*** The audio output of the module is isolated using two 600:600-ohm transformers to reduce or eliminate the ground loop problems which can easily occur in SDR systems
*** I2C Interface
+
*** The module is designed to directly drive a stereo input sound-card or with a polyphase filter card
** Controls frequencies with rotary encoder
+
*** Receiver board has a socket for the standard QRP Labs Band Pass Filter kit which can be routed to an external bandpass filter switch card
** 1Hz, 10 Hz, 100 Hz, 1 KHz, 10 KHz, 100 KHz, 1 MHz, 10 MHz steps (software controllable)
+
*** The receiver requires a local oscillator (LO) input at 4x the receive frequency
* Si5351A Oscillator
+
*** [http://qrp-labs.com/images/receiver/receiver2.pdf Receiver Build instructions]
** 3 Outputs
+
** [[RF Band Pass Filters|QRP Labs Band Pass Filter]]
** 27 MHz TCXO crystal
+
*** Can be used with a [https://qrp-labs.com/ultimatelpf.html Switched Bandpass filter board] for multiband operation
*** Adjustable to 0.01 Hz precision
+
*** [http://qrp-labs.com/bpfkit.html 10/15/20/40/80M QRP Labs Band Pass Filter Kits]
** I2C Interface
+
*** [https://qrp-labs.com/images/bpfkit/bpf2.pdf Band Pass Filter Build instructions]
* 3.3V, 50 Ohm output
+
** [https://qrp-labs.com/polyphase QRP Labs Polyphase filter]
* Power
+
*** Polyphase network plug-in module kit cancels the unwanted sideband and produces a single sideband (SSB) output
** [[Mini360_Buck_Converter|MINI-360 DC/DC Buck regulator]]
+
*** [http://qrp-labs.com/images/polyphase/polyphase2a.pdf Polyphase Filter Build instructions]
** 7-24 VDC
+
* Band Pass Filter and Polyphase filter mount on Receiver Module
* Fits in standard extruded enclosures
+
* Current draw - measured total 70 mA (5V regulator
 
+
* The receiver module is sized 80 x 37mm
=== Arduino Pro Mini ===
 
 
 
* [https://www.ebay.com/itm/5Pcs-Pro-Mini-3-3V-Arduino-Compatible-Board-8MHz/223719575050?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 ebay listing]
 
 
 
[[File:ArdruinoProMini-EBAY_PART-720px.png]]
 
 
 
== Connectors ==
 
 
 
=== J1 - OLED ===
 
 
 
# SDA
 
# SCL
 
# Vcc
 
# GND
 
 
 
[[file:VFO-003_J1.PNG]]
 
 
 
=== J2 - Display Encoder/OLED (Display card) ===
 
 
 
# Encoder A
 
# Encoder B
 
# Encoder Switch
 
# SCL
 
# SDA
 
# Vcc
 
# GND
 
 
 
[[file:VFO-003_J2.PNG]]
 
 
 
=== J3 - Display Encoder/OLED (Main card) ===
 
  
# Encoder A
+
=== Build / Assembly ===
# Encoder B
 
# Encoder Switch
 
# SCL
 
# SDA
 
# Vcc
 
# GND
 
  
[[file:VFO-003_J3.PNG]]
+
* Power supply + 12V in
 +
** Distribute 12V using [[TinyGrid85]] card with caps
 +
** Needs 5V supply
 +
*** Partly populated [[TinyGrid85]] card with caps and 5V regulator (no ATTiny85 chip)
 +
** Opamps can be powered from 5V or 12-14V (for higher dynamic range)
 +
* [[AudioAmp386|Audio Amplifier]]
 +
* The receiver requires a local oscillator (LO) input at 4x the receive frequency
 +
** Using [[VFO-003]] with [https://github.com/land-boards/lb-Arduino-Code/tree/master/LBCards/VFO-003_4X 4x output software option]
 +
** [https://github.com/etherkit/Si5351Arduino/tree/master/src Si5351 Driver]
  
=== J4 - FTDI ===
+
== Silkscreen / Pinout ==
  
Can install 1x6 header on the Arduino Pro Mini and not install this
+
[[file:IQ_RX_PCB.PNG]]
  
# GND
+
=== Pins ===
# GND
 
# Vcc
 
# RX
 
# Tx
 
# DTR
 
  
[[file:VFO-003_J4.PNG]]
+
* IQ pins
 +
* I, GND, Q outputs
 +
* Power pins
 +
* GND, +5V, +5V or +12V to +14V
 +
* Tx Mute Input
 +
** 5V mutes inputs
 +
* LO input
 +
** 3.3V from Si5351A oscillators
 +
* IF input
 +
** From external Bandpass Filter Switch
  
=== J5 - Arduino A0-A3/C10-D13 ===
+
== Receiver Module ==
  
# A3
+
[[file:QRP-Labs_Receiver-Base_P1969-720px.jpg]]
# A2
 
# A0
 
# D13
 
# D12
 
# D11
 
# D10
 
# Vcc (not connected on Rev 1 PCB)
 
# GND (not connected on Rev 1 PCB)
 
  
[[file:VFO-003_J5.PNG]]
+
== Polyphase Module ==
  
=== J6 - Disconnect for Mini-360 Power Supply ===
+
*  Important to observe part outlines
 +
** Adjacent resistors can be put in "sideways"
  
* The [[Mini360 Buck Converter]] comes adjusted for a very high output voltage
+
[[file:QRP-Labs_Polyphase-Filter_P1966-500px.jpg]] [[file:Polyphase-pcb.PNG]]
* Remove jumper to adjust the output voltage to 3.3V without powering the rest of the card
 
* Install to power the card from the power supply
 
  
[[file:VFO-003_J6.PNG]]
+
[[file:Polyphase-pcb-2.png]]
  
[[file:Mini-360-004.jpg]]
+
[[file:Polyphase-Schematic.PNG]]
  
=== J7 - Output disconnects ===
+
* USB/LSB select jumpers
 +
** Set to USB in the above picture
  
* Cut rear side trace to disconnect
+
[[file:Polyphase_LSB-USB-Jumpers.PNG]]
* Can be used to install external LP filters
 
* Limited use due to 74AC14 drivers
 
  
[[file:VFO-003_J7.PNG]]
+
== Bandpass Module ==
  
=== J7 - Arduino P5-P9 ===
+
* 20M - 14 MHz Filter
  
# P5
+
[[file:QRP-Labs_BandPass-Filter_P1963-720px.jpg]]
# P6
 
# P7
 
# P8
 
# P9
 
# Vcc
 
# GND
 
  
[[file:VFO-003_J8.PNG]]
+
[[file:Bandpass_Filter_Schematic.PNG]]
  
== Schematic ==
+
* NanoVNA
 +
** 12-16 MHz
  
* [https://github.com/land-boards/lb-boards/blob/master/HamRadio/VFO-003/Documents/Schematics/VFO-003_Rev3_Schematic.pdf Rev 3 schematic]
+
[[FILE:14MHz_12-16MHz_Band_Pass_Filter-2.png]]
  
== Software ==
+
* Data
  
* [https://github.com/land-boards/lb-Arduino-Code/tree/master/LBCards/VFO-003 GitHub Repository]
+
[[FILE:14MHz_12-16MHz_Band_Pass_Filter-Data.png]]
  
== Mechanicals ==
+
[[FILE:  14MHz_12-16MHz_Band_Pass_Filter-Analysis.png]]
  
[[file:VFO-003_FrontPanel_Holes.PNG]]
+
== Build Issues ==
  
[[file:VFO-003_RearPanel_Holes.PNG]]
+
* Transformers don't fit well and crowd parts around them
 +
* QRP Labs polyphase module pics are for older revision card
 +
* One of the two variable caps on the Bandpass filter was very hard to turn even after the first turn
  
== Assembly Sheet / Parts List ==
+
== Reference Documents ==
  
[[VFO-003 Assembly Sheet - Rev 1]]
+
* [https://wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf Ultra Low Noise, High Performance, Zero IF Quadrature Product Detector and Preamplifier]
 +
* [http://antennoloog.nl/data/documents/Understanding_and_designing_Polyphase_networks_V4.0.pdf Understanding and Designing Sequence Asymmetric Polyphase Networks]
 +
* [https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qst/1991/12/page29/ The double-tuned Circuit: An experimenter's tutorial]
 +
* [http://hanssummers.com/polyphase 40/80m CW/SSB receiver]
 +
* [http://hanssummers.com/images/stories/polyphase/polyphase.pdf Experimental Polyphase Receiver]
 +
* [http://www.arrl.org/files/file/Technology/tis/info/pdf/030304qex020.pdf A Software Defined Radio for the Masses]
 +
* [http://norcalqrp.org/files/AustinNC2030Presentation.pdf Very High Performance Image Rejecting Direct Conversion Receivers] - NC2030 Radio

Revision as of 00:02, 22 November 2021

QRP-Labs P1956-720px.jpg

Features

Build / Assembly

Silkscreen / Pinout

IQ RX PCB.PNG

Pins

  • IQ pins
  • I, GND, Q outputs
  • Power pins
  • GND, +5V, +5V or +12V to +14V
  • Tx Mute Input
    • 5V mutes inputs
  • LO input
    • 3.3V from Si5351A oscillators
  • IF input
    • From external Bandpass Filter Switch

Receiver Module

QRP-Labs Receiver-Base P1969-720px.jpg

Polyphase Module

  • Important to observe part outlines
    • Adjacent resistors can be put in "sideways"

QRP-Labs Polyphase-Filter P1966-500px.jpg Polyphase-pcb.PNG

Polyphase-pcb-2.png

Polyphase-Schematic.PNG

  • USB/LSB select jumpers
    • Set to USB in the above picture

Polyphase LSB-USB-Jumpers.PNG

Bandpass Module

  • 20M - 14 MHz Filter

QRP-Labs BandPass-Filter P1963-720px.jpg

Bandpass Filter Schematic.PNG

  • NanoVNA
    • 12-16 MHz

14MHz 12-16MHz Band Pass Filter-2.png

  • Data

14MHz 12-16MHz Band Pass Filter-Data.png

14MHz 12-16MHz Band Pass Filter-Analysis.png

Build Issues

  • Transformers don't fit well and crowd parts around them
  • QRP Labs polyphase module pics are for older revision card
  • One of the two variable caps on the Bandpass filter was very hard to turn even after the first turn

Reference Documents