V5.6.5 · Production Ready

Amateur Radio
Anytime, Anywhere

MRRC is the universal HF route in the VLSC remote radio ecosystem. Control your HF radio from phone, tablet, or computer. Opus-optimized audio, WDSP professional noise reduction, AI voice assistant, CW/FT8 digital modes, studio-grade TX audio processing, and 3-layer PTT safety.

<100msTX/RX Switch
99%+PTT Reliability
15-20dBWDSP NR
V5.6.5280+ Commits

Where MRRC Fits

Use MRRC for universal CAT-based HF remote control. Other radio classes map to dedicated VLSC projects.

Built for Modern HAM Radio

Ultra Low Latency

TX ~65ms / RX ~51ms, <100ms TX↔RX switch. Opus 28kbps codec, AudioWorklet playback, Int16 transport — professional real-time experience.

  • Opus codec · AudioWorklet pipeline
  • Under 100ms TX↔RX switching
  • Int16 lossless transport option

WDSP Professional NR

OpenHPSDR WDSP library: NR2 spectral noise reduction 15-20dB, AGC (4 modes), ANF auto-notch, NB noise blanker — SSB-optimized.

  • NR2 spectral NR 15-20dB
  • AGC 4-mode · ANF · NB
  • SSB-optimized DSP chain

AI Voice Assistant

Whisper ASR + Qwen3-TTS: speech-to-text receive, text-to-speech transmit with automatic phonetic alphabet callsign conversion.

  • Whisper ASR RX → text
  • Qwen3 TTS text → TX voice
  • Auto phonetic callsign conversion

CW + FT8 Digital Modes

Browser-first AI CW decode (<2MB ONNX, <50ms). FT8 ULTRON Console: JTDX/WSJT-X/MSHV integration with live waterfall, auto-sequencer, DXCC tracking.

  • ONNX AI CW decode · QSO state machine
  • FT8 ULTRON: JTDX/WSJT-X/MSHV bridge
  • Auto-sequencer · DXCC tracking

3-Layer PTT Safety

Release ACK protocol with 3× retry + redundant audio-path fallback, 120s TOT hard limit, touch-move auto-release, visibility-change forced stop — prevents stuck transmissions.

  • ACK × 3 retry + audio-path fallback
  • 120s TOT hard limit
  • Touch-move / visibility-change stop

ATR-1000 + RagChew Audio

ATR-1000: 0-200W real-time power display, SWR 1.0-9.99, smart frequency→tuner learning. RagChew TX chain: low-cut 150Hz, presence +3dB@2.4kHz, 3:1 compressor, -50dB noise gate.

  • ATR-1000: power/SWR/tuner learning
  • RagChew: EQ + compressor + noise gate
  • MemoryChannelManager · LearningBuffer

Experience It Yourself

All demos connect to a live FT-710 station. Try each interface — mobile, voice, CW, SDR, FT8, recordings.

Set Up in 5 Minutes

Connect Your Radio

CAT serial + audio cable to your computer. MRRC auto-detects via Hamlib

rigctld -m 2 -r /dev/ttyUSB0 -s 38400

Install MRRC

Clone the repo and run the setup script

git clone https://github.com/cheenle/UHRR_mac && cd UHRR_mac && ./install.sh

Start the Server

Launch the Python backend — TLS, WebSocket, and audio pipeline in one process

python3 server.py --port 8877

Open Your Browser

Any device on your network — phone, tablet, or computer

https://radio-host:8877/mobile_modern.html
Installation Guide