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− | [[file:QRP-Labs_P1956-720px.jpg]]
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− | == Features ==
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− | * Three modules
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− | ** [http://qrp-labs.com/receiver QRP Labs High Performance Receiver Module]
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− | *** Direct Conversion Receiver
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− | *** Uses a Quadrature Sampling Detector (QSD), also known as a Tayloe Detector
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− | *** [https://www.onsemi.com/pdf/datasheet/fst3253-d.pdf FST3253] Mixer is arranged as a double-balanced mixer for maximum performance
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− | *** Circuit to mute receiver during transmit
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− | *** [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
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− | *** 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
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− | *** The module is designed to directly drive a stereo input sound-card or with a polyphase filter card
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− | *** 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
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− | *** The receiver requires a local oscillator (LO) input at 4x the receive frequency
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− | **** Using [[VFO-003]] with [https://github.com/land-boards/lb-Arduino-Code/tree/master/LBCards/VFO-003_4X 4x output software option]
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− | *** [http://qrp-labs.com/images/receiver/receiver2.pdf Receiver Build instructions]
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− | ** [[RF Band Pass Filters|QRP Labs Band Pass Filter]]
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− | *** Can be used with a [https://qrp-labs.com/ultimatelpf.html Switched Bandpass filter board] for multiband operation
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− | *** [http://qrp-labs.com/bpfkit.html 10/15/20/40/80M QRP Labs Band Pass Filter Kits]
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− | *** [https://qrp-labs.com/images/bpfkit/bpf2.pdf Band Pass Filter Build instructions]
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− | ** [https://qrp-labs.com/polyphase QRP Labs Polyphase filter]
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− | *** Polyphase network plug-in module kit cancels the unwanted sideband and produces a single sideband (SSB) output
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− | *** [http://qrp-labs.com/images/polyphase/polyphase2a.pdf Polyphase Filter Build instructions]
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− | * Band Pass Filter and Polyphase filter mount on Receiver Module
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− | * Power supply
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− | ** Needs 5V supply
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− | ** Opamps can be powered from 5V or 12-14V (for higher dynamic range)
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− | * The receiver module is sized 80 x 37mm
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− |
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− | == Silkscreen / Pinout ==
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− | [[file:IQ_RX_PCB.PNG]]
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− | === Pins ===
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− | * IQ pins
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− | * I, GND, Q outputs
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− | * Power pins
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− | * GND, +5V, +5V or +12V to +14V
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− | * Tx Mute Input
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− | ** 5V mutes inputs
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− | * LO input
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− | ** 3.3V from Si5351A oscillators
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− | * IF input
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− | ** From external Bandpass Filter Switch
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− |
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− | == Receiver Module ==
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− |
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− | [[file:QRP-Labs_Receiver-Base_P1969-720px.jpg]]
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− | == Polyphase Module ==
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− | [[file:QRP-Labs_Polyphase-Filter_P1966-720px.jpg]] [[file:Polyphase-pcb.PNG]]
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− | == Bandpass Module ==
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− | [[file:QRP-Labs_BandPass-Filter_P1963-720px.jpg]]
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− | [[file:Bandpass_Filter_Schematic.PNG]]
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− |
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− | == Build Issues ==
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− |
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− | * Transformers don't fit well and crowd parts around them
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− | * QRP Labs polyphase module pics are for older revision card
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− | == Reference Documents ==
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− | * [https://wparc.us/presentations/SDR-2-19-2013/Tayloe_mixer_x3a.pdf Ultra Low Noise, High Performance, Zero IF Quadrature Product Detector and Preamplifier]
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− | * [http://antennoloog.nl/data/documents/Understanding_and_designing_Polyphase_networks_V4.0.pdf Understanding and Designing Sequence Asymmetric Polyphase Networks]
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− | * [https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qst/1991/12/page29/ The double-tuned Circuit: An experimenter's tutorial]
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− | * [http://hanssummers.com/polyphase 40/80m CW/SSB receiver]
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− | * [http://hanssummers.com/images/stories/polyphase/polyphase.pdf Experimental Polyphase Receiver]
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− | * [http://www.arrl.org/files/file/Technology/tis/info/pdf/030304qex020.pdf A Software Defined Radio for the Masses]
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− | * [http://norcalqrp.org/files/AustinNC2030Presentation.pdf Very High Performance Image Rejecting Direct Conversion Receivers] - NC2030 Radio
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