Difference between revisions of "QRP Labs High Performance SDR Receiver"
Jump to navigation
Jump to search
Blwikiadmin (talk | contribs) |
Blwikiadmin (talk | contribs) |
||
(16 intermediate revisions by the same user not shown) | |||
Line 16: | Line 16: | ||
*** [http://qrp-labs.com/images/receiver/receiver2.pdf Receiver Build instructions] | *** [http://qrp-labs.com/images/receiver/receiver2.pdf Receiver Build instructions] | ||
** [[RF Band Pass Filters|QRP Labs Band Pass Filter]] | ** [[RF Band Pass Filters|QRP Labs Band Pass Filter]] | ||
− | |||
*** [http://qrp-labs.com/bpfkit.html 10/15/20/40/80M QRP Labs Band Pass Filter Kits] | *** [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/images/bpfkit/bpf2.pdf Band Pass Filter Build instructions] | ||
+ | *** Can be used with a [https://qrp-labs.com/ultimatelpf.html Switched Bandpass filter board] for multiband operation | ||
+ | **** Look for "Using the Rev. 5 relay-switched LPF kit to switch Band Pass Filters" for jumpers and I/O connections | ||
+ | **** [https://www.qrp-labs.com/images/ultimatelpf/assembly_ulpf.pdf Relay Switched Kit Build Instructions] | ||
+ | **** [https://www.qrp-labs.com/ultimatelpf/relaydriver Relay driver for Relay Switched Kit] | ||
+ | ***** [[6 Channel Relay Driver Card]] | ||
+ | **** Use bypass filter card on receiver when using Switched Bandpass filter, filters get installed in the switch card | ||
** [https://qrp-labs.com/polyphase QRP Labs Polyphase filter] | ** [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 | *** Polyphase network plug-in module kit cancels the unwanted sideband and produces a single sideband (SSB) output | ||
Line 45: | Line 50: | ||
** CLK2 turned off | ** CLK2 turned off | ||
* [[SMA-HDRS]] board to feed LO into card | * [[SMA-HDRS]] board to feed LO into card | ||
+ | ** Mount 1x3 female flat to board | ||
+ | * Used right angle SMT for RF in connector - works well | ||
== Silkscreen / Pinout == | == Silkscreen / Pinout == | ||
Line 70: | Line 77: | ||
* Important to observe part outlines | * Important to observe part outlines | ||
− | ** Adjacent resistors can be | + | ** Adjacent resistors can be incorrectly installed "sideways" |
[[file:QRP-Labs_Polyphase-Filter_P1966-500px.jpg]] [[file:Polyphase-pcb.PNG]] | [[file:QRP-Labs_Polyphase-Filter_P1966-500px.jpg]] [[file:Polyphase-pcb.PNG]] | ||
Line 85: | Line 92: | ||
== Bandpass Module == | == Bandpass Module == | ||
+ | * [[RF_Band_Pass_Filters#QRP_Labs_Bandpass_Filter|Bandpass Filter module]] | ||
* 20M - 14 MHz Filter | * 20M - 14 MHz Filter | ||
Line 105: | Line 113: | ||
* Transformers don't fit well and crowd parts around them | * Transformers don't fit well and crowd parts around them | ||
− | * QRP Labs polyphase module pics are for older revision card | + | ** 3.5mm jack crowded |
+ | ** C1/C2 footprints overlap | ||
+ | * QRP Labs polyphase module pics are for older revision card before 47 ohm resistors were added | ||
* One of the two variable caps on the Bandpass filter was very hard to turn even after the first turn | * One of the two variable caps on the Bandpass filter was very hard to turn even after the first turn | ||
Latest revision as of 17:10, 28 January 2022
Contents
Features
- Three modules
- QRP Labs High Performance Receiver Module
- Direct Conversion Receiver
- Uses a Quadrature Sampling Detector (QSD), also known as a Tayloe Detector
- FST3253 Mixer is arranged as a double-balanced mixer for maximum performance
- Circuit to mute receiver during transmit
- Low noise LM4562 op-amps are used in instrumentation amplifier configuration to provide excellent common mode noise rejection
- 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
- 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
- Receiver Build instructions
- QRP Labs Band Pass Filter
- 10/15/20/40/80M QRP Labs Band Pass Filter Kits
- Band Pass Filter Build instructions
- Can be used with a Switched Bandpass filter board for multiband operation
- Look for "Using the Rev. 5 relay-switched LPF kit to switch Band Pass Filters" for jumpers and I/O connections
- Relay Switched Kit Build Instructions
- Relay driver for Relay Switched Kit
- Use bypass filter card on receiver when using Switched Bandpass filter, filters get installed in the switch card
- QRP Labs Polyphase filter
- Polyphase network plug-in module kit cancels the unwanted sideband and produces a single sideband (SSB) output
- Polyphase Filter Build instructions
- QRP Labs High Performance Receiver Module
- 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
Build / Assembly
- 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)
- Audio Amplifier
- The receiver requires a local oscillator (LO) input at 4x the receive frequency
- Using VFO-003 with 4x output option software
- CLK0 = VCO clock
- 14MHz
- 4x
- CLK1 - RF test signal
- 60 dB attenuator into RF input
- 60+40 dB = 100 dB attenuator into RF input
- CLK2 turned off
- SMA-HDRS board to feed LO into card
- Mount 1x3 female flat to board
- Used right angle SMT for RF in connector - works well
Silkscreen / Pinout
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
Polyphase Module
- Important to observe part outlines
- Adjacent resistors can be incorrectly installed "sideways"
- USB/LSB select jumpers
- Set to USB in the above picture
Bandpass Module
- Bandpass Filter module
- 20M - 14 MHz Filter
- NanoVNA
- 12-16 MHz
- Data
Build Issues
- Transformers don't fit well and crowd parts around them
- 3.5mm jack crowded
- C1/C2 footprints overlap
- QRP Labs polyphase module pics are for older revision card before 47 ohm resistors were added
- One of the two variable caps on the Bandpass filter was very hard to turn even after the first turn
Reference Documents
- Ultra Low Noise, High Performance, Zero IF Quadrature Product Detector and Preamplifier
- Understanding and Designing Sequence Asymmetric Polyphase Networks
- The double-tuned Circuit: An experimenter's tutorial
- 40/80m CW/SSB receiver
- Experimental Polyphase Receiver
- A Software Defined Radio for the Masses
- Very High Performance Image Rejecting Direct Conversion Receivers - NC2030 Radio