Difference between pages "A Termination Insensitive Amplifier for Bidirectional Transceivers" and "QRP Labs High Performance SDR Receiver"

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[[file:W7ZOI_TIA_3D.png]]
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[[file:QRP-Labs_P1956-720px.jpg]]
  
== W7ZOI Design ==
+
== Features ==
  
* Paper - [http://w7zoi.net/bidirectional_matched_amplifier.pdf A Termination Insensitive Amplifier for Bidirectional Transceivers] - W7ZOI (Wes Hayward) design
+
* Three modules
* [http://w7zoi.net/transistor_models_and_the_fba.pdf Transistor Models and the Feedback Amplifier]
+
** [http://qrp-labs.com/receiver QRP Labs High Performance Receiver Module]
* Termination Insensitive - input impedance that does not depend upon the output load
+
*** Direct Conversion Receiver
* Bi-directional - amplifiers in both directions
+
*** Uses a Quadrature Sampling Detector (QSD), also known as a Tayloe Detector
* 50 ohms in/out
+
*** [https://www.onsemi.com/pdf/datasheet/fst3253-d.pdf FST3253] Mixer is arranged as a double-balanced mixer for maximum performance
* BNC or SMA Connectors
+
*** Circuit to mute receiver during transmit
* Transformer-less
+
*** [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
* Power applied to one half at a time - determines signal flow direction
+
*** 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
* ~30 mA per side
+
*** The module is designed to directly drive a stereo input sound-card or with a polyphase filter card
 +
*** 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
 +
*** The receiver requires a local oscillator (LO) input at 4x the receive frequency
 +
*** [http://qrp-labs.com/images/receiver/receiver2.pdf Receiver Build instructions]
 +
** [[RF Band Pass Filters|QRP Labs Band Pass Filter]]
 +
*** Can be used with a [https://qrp-labs.com/ultimatelpf.html Switched Bandpass filter board] for multiband operation
 +
*** [http://qrp-labs.com/bpfkit.html 10/15/20/40/80M QRP Labs Band Pass Filter Kits]
 +
*** [https://qrp-labs.com/images/bpfkit/bpf2.pdf Band Pass Filter Build instructions]
 +
** [https://qrp-labs.com/polyphase QRP Labs Polyphase filter]
 +
*** Polyphase network plug-in module kit cancels the unwanted sideband and produces a single sideband (SSB) output
 +
*** [http://qrp-labs.com/images/polyphase/polyphase2a.pdf Polyphase Filter Build instructions]
 +
* Band Pass Filter and Polyphase filter mount on Receiver Module
 +
* Current draw - measured total 70 mA (5V regulator
 +
* The receiver module is sized 80 x 37mm
  
=== W7ZOI Schematic ===
+
=== Build / Assembly ===
  
[[FILE:W7ZOI_SCHEMATIC.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]
  
=== * Use ===
+
== Silkscreen / Pinout ==
  
* Between RF/LO mixer (IF output/input) and crystal filter
+
[[file:IQ_RX_PCB.PNG]]
* Between Crystal Filter and Product Detector / Balanced Modulator
 
  
[[file:FARHADPNG.PNG]]
+
=== Pins ===
  
== Schematic in KiCAD ==
+
* 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
  
* Single channel
+
== Receiver Module ==
* With SPICE directives
 
  
[[file:W7ZOI_SCHEMATIC_KiCAD.PNG]]
+
[[file:QRP-Labs_Receiver-Base_P1969-720px.jpg]]
  
* Both channels
+
== Polyphase Module ==
* With SPICE directives
 
  
[[file:W7ZOI_SCHEMATIC_KiCAD-2.PNG]]
+
*  Important to observe part outlines
 +
** Adjacent resistors can be put in "sideways"
  
== NGSPICE Simulation ==
+
[[file:QRP-Labs_Polyphase-Filter_P1966-500px.jpg]] [[file:Polyphase-pcb.PNG]]
  
* NGSPICE run from KiCAD
+
[[file:Polyphase-pcb-2.png]]
** [http://ngspice.sourceforge.net/ngspice-eeschema.html Tutorial: ngspice simulation in KiCad/Eeschema]
 
* +24 dB @12V
 
* 2N3904 Alternate Node Sequence (MMBT3903 - SOT23)
 
** KiCAD order 1 2 3 is the SPICE normal order
 
** NGSPICE order: 3 1 2
 
  
[[file:W7ZOI_Simulation_KiCAD-3.PNG]]
+
[[file:Polyphase-Schematic.PNG]]
  
* Closely matches
+
* USB/LSB select jumpers
 +
** Set to USB in the above picture
  
[[file:W7ZOI_Gainz.PNG]]
+
[[file:Polyphase_LSB-USB-Jumpers.PNG]]
  
* Across Band
+
== Bandpass Module ==
[[file:W7ZOI_Simulation_KiCAD_S2.PNG]]
 
  
== CAD ==
+
* 20M - 14 MHz Filter
  
[[FILE:W7ZOI_CAD.PNG]]
+
[[file:QRP-Labs_BandPass-Filter_P1963-720px.jpg]]
  
== SMT Build ==
+
[[file:Bandpass_Filter_Schematic.PNG]]
  
[[FILE:W7ZOI_TIA_SMD_3D.png]]
+
* NanoVNA
 +
** 12-16 MHz
  
[[FILE:W7ZOI_TIA_SMT_CAD.PNG]]
+
[[FILE:14MHz_12-16MHz_Band_Pass_Filter-2.png]]
  
== Videos ==
+
* Data
  
<video type="youtube">JjcxEYk9atg</video>
+
[[FILE:14MHz_12-16MHz_Band_Pass_Filter-Data.png]]
  
<video type="youtube">CpQK0W7TY5g</video>
+
[[FILE:  14MHz_12-16MHz_Band_Pass_Filter-Analysis.png]]
  
<video type="youtube">7TtKE39TWpI</video>
+
== Build Issues ==
  
<video type="youtube">T8lq8Qtjqe0</video>
+
* 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 ==
+
== Reference Documents ==
  
* [[W7ZOI TIA 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