Simple, fun and versatile QRP SSB HF transceiver with built-in DSP and SDR functions EER E-level drive SSB launch stage 13.8V power supply provides about 10W PEP SSB output Full mode support: USB, LSB, CW, AM, FM DSP filter: 4000, 2500, 1700, 500, 200, 100, 50Hz passband DSP functions: automatic gain control (AGC), noise reduction (NR), voice trigger, voice trigger Xmit (VOX), RX attenuator attenuator (ATT), TX noise gate, TX driver control, volume control, dBm/S- meter SSB reverse sideband/carrier suppression transmission: better than -45dBc, IMD3 (two tones)) 33dBc, reception: better than -50dBc Multi-band support, continuously adjustable in the 160m-10m frequency band (performance drops from 20kHz..99MHz) Open source firmware, built in for Arduino IDE; Allows experimentation, can add new functions, can share contributions through Github, software complexity: 2000 lines of code Software-based VOX can be used as a fast fully invasive (QSK and semi-QSK operation), or auxiliary operation in digital mode (without CAT or PTT interface) for RX/TX switching, external PTT output with TX/PA control delay Simple installation modification through 8 component changes and 8 lines Lightweight, low-cost transceiver: Thanks to the EER transmitter Class E, it has high power efficiency (no need for bulky heat sinks), and simple design (no need for complex balanced linear power amplifiers) SSB transmitter stage based entirely on digital and software: By controlling the phase of the SI5351 PLL (Mini frequency changes over 800kbit/s through I2C) and the amplitude of the PA (PWM through PWM), the microphone input is sampled and the SSB signal is reconstructed. PA key shaping circuit) All-digital and software-based SDR receiver stage (optional): I/Q (complex) signals are sampled from a quadrature sampling detector digital mixer, and a 90-degree phase shift (Hilber transform) is performed in software) And eliminate one by adding sidebands Three independent switchable analog front-end receiver attenuators (0dB, -13dB, -20dB, -33dB, -53dB, -60dB, -73dB) Receiver noise level MDS: -135 dBm (200Hz BW)) at 28MHz Receiver front-end selectivity: steep tuning frequency -45dB / ten roll-off +/- 2kHz Blocking dynamic range: 20kHz offset 123dB, 2kHz offset 78dB CW decoder, straight/Iambic-A/B keyer VFO A/B+RIT and Split, and switch the corresponding relay band filter through I2C CAT support (TS480 subset), can stream o, buttons, and display text through CAT This is probably the most cost-effective and easy-to-build stand-alone SDR/SSB transceiver. Great simplification Simplifies the original QCX circuit (that is, the installation components are reduced by 50%, the installation components are reduced by 50%, no complicated transformer windings, and no wiring procedures are required), and it has a wider range of uses Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the United States, the Philippines,Taiwan and so on.