Features - MRRC Mobile Remote Radio Control

⚡ Ultra-Low Latency Audio Streaming

<100ms

TX/RX Switch Latency

~65ms

TX Latency

~51ms

RX Latency

Technical Implementation

AudioWorklet Player: Uses Web Audio API's AudioWorklet to reduce main thread jitter, achieving low-latency audio playback
Interval Buffering: 16/32 frame configuration, balancing latency and stability
PTT Debounce: 50ms debounce delay, prevents duplicate commands
Buffer Clear Optimization: Immediately clears RX buffer on TX release
Int16 Encoding: 50% bandwidth reduction vs Float32

Optimization Comparison

Metric	Traditional Solution	MRRC Optimized
TX→RX Switch	2-3 seconds	<100ms
PTT Reliability	95%	99%+
Audio Bandwidth	256kbps	128kbps

🔧 WDSP Professional Noise Reduction

Integrates Warren Pratt's Digital Signal Processing library, the high-performance DSP library from the OpenHPSDR project, widely used in Thetis, piHPSDR and other professional amateur radio software.

Core Features

🔇

NR2 Spectral NR

Spectral subtraction based noise reduction, 15-20dB depth, extremely high speech fidelity, specifically optimized for SSB voice

⚡

NB Noise Blanker

Eliminates impulse interference, effectively suppresses electrical sparks, lightning and other burst noise

🎯

ANF Auto Notch

Automatically eliminates single-tone interference, suitable for CW tones, carrier interference scenarios

📊

AGC Auto Gain

4 selectable modes: LONG/SLOW/MED/FAST, adapts to different signal environments

Comparison with RNNoise

Feature	WDSP (NR2)	RNNoise
Noise Reduction Depth	15-20 dB	10-15 dB
Speech Fidelity	⭐⭐⭐⭐⭐	⭐⭐⭐
SSB Optimization	✅ Specifically Optimized	❌ General Voice
Latency	< 20ms	30-50ms

📱 Mobile Deep Optimization

Touch Optimization

Large PTT Button: Bottom-center design, optimized for thumb operation area
Touch Enhancement: 300ms anti-mistouch, long-press/short-press differentiation
Haptic Feedback: PTT button vibration feedback (iOS/Android support)
Safe Area Adaptation: Automatically adapts to notched screens and bottom indicators

PWA Support

Add to Home Screen: Supports running as standalone application
Offline Access: Service Worker caches critical resources
Fast Launch: Optimized startup flow, instant app opening

Device Compatibility

📱 iPhone 15 Series ✓ Perfect Support

📱 iPhone 12/13/14 ✓ Perfect Support

📱 Android Flagship ✓ Perfect Support

📱 iPad/Tablet ✓ Supported

📊 ATR-1000 Power Meter/Tuner Integration

Real-time Monitoring

Power Display: 0-200W real-time forward power display
SWR Monitoring: 1.0-9.99 real-time SWR display
Relay Status: LC/CL network, inductance/capacitance values display
Display Latency: <200ms real-time update

Smart ATU Learning

Learning Conditions

SWR between 1.0 ~ 1.5
Forward power > 5W
5 consecutive samples meeting conditions before recording

Quick Tune

Automatically applies learned tuner parameters when frequency changes
±10kHz tolerance range lookup
Parameters persisted to JSON file

Protocol Details

Communication Protocol: WebSocket + JSON
Data Frame Format: FF CMD LEN DATA...
Response Example: ff050701031b1e000e01
  → SW=CL, IND=30(0.3uH), CAP=27(270pF)

🎙️ AI Voice Assistant

Speech Recognition (ASR)

Whisper Local Model: OpenAI Whisper base model, 150MB, runs completely locally
Real-time Recognition: Transceiver receive voice real-time to text
Multi-language Support: Chinese, English, Japanese, etc.
Callsign Recognition: Automatically recognizes callsign format

Speech Synthesis (TTS)

Qwen3-TTS Integration: Alibaba 1.7B model, true baritone voice
Phonetic Alphabet: Callsigns automatically converted to international phonetic pronunciation
Smart Switching: Chinese/English automatically selects best voice
PTT Integration: Hold transmit button auto-synthesizes and transmits

Use Cases

Receive Recognition: Other party's voice → Text displayed in dialog

Reply Synthesis: Input text → Synthesize voice → Hold PTT to transmit

Callsign Optimization: "BG1SB" → "BG1SB (Bravo Golf One Sierra Bravo)"

🎚️ RagChew TX Audio Processing Chain

V5.1 introduced a complete Web Audio API-based transmit audio processing chain — studio-grade speech optimization for amateur radio.

Processing Chain (V5.1+)

Stage	Parameter	Value	Purpose
4-Band EQ	Low-Cut / Mid-Cut / Presence / High-Cut	150Hz / -2dB@500Hz / +3dB@2.4kHz / 3kHz	Shape voice for SSB clarity
Dynamic Compressor	Ratio / Attack / Release	3:1 / 5ms / 50ms	Consistent modulation level
Noise Gate	Threshold	-50dB	Silence background when not speaking

TX Equalizer Presets

For simple 3-band EQ (legacy mode):

Preset	Low (<100Hz)	Mid (1500Hz)	High (>2700Hz)	Use Case
HF Voice	-20dB	+6dB	-20dB	Standard SSB communication
Mobile Optimized	-15dB	+8dB	-24dB	Phone microphone
Weak Signal	-20dB	+10dB	-25dB	DX / contest

📶 Real-time Network Monitoring

V5.3 introduced live network bandwidth and latency monitoring, giving operators full visibility into connection quality.

Bandwidth Display: Real-time upstream/downstream throughput (kbps)
Latency Monitor: WebSocket ping-pong round-trip time display
Visual Enhancements: Glow effect, larger fonts, color-coded thresholds
Status Bar: Streamlined UI removing redundant CTL/RX/TX indicators

📡 CW Real-time Decoding System

Deep learning based Morse code real-time decoding, supports frontend ONNX inference and backend PyTorch decoding dual modes.

Technical Architecture

Browser-First AI: AI capability pushed to browser side, zero backend dependency
Dual-Mode Decoding: Frontend ONNX (2MB) + backend morse-deep-learning
Ultra-Low Latency: Frontend inference <50ms, end-to-end <100ms
High Accuracy: Character Error Rate (CER) <3% @ SNR>-5dB

Core Features

🧠

AI Decode Engine

web-deep-cw-decoder lightweight model, CRNN + CTC architecture, runs directly in browser

📱

QSO State Machine

Smart recognition of callsign/RST/QTH/NAME, auto-generates reply suggestions, follows HAM Radio conventions

📤

CW Transmit

Text to Morse code, supports 10-40 WPM speed adjustment, side tone frequency configurable

🎚️

Filter Control

Supports 500Hz / 1KHz / 2.4KHz bandwidth switching, dedicated CW narrowband optimization

Try It Live

CW Real-time Decode CW Test

📉 NanoVNA Vector Network Analyzer

Web Interface: Built-in NanoVNA Web control interface
Standalone PWA: Can be added to home screen as independent application
Real-time Measurement: S11, S21 parameters real-time display
Smith Chart: Supports Smith chart display

📻 FT8/ULTRON Remote Console (V5.6+)

ULTRON is MRRC's FT8 digital mode remote console (introduced V4.9, overhauled V5.6), providing a full-featured browser-based interface to JTDX/WSJT-X/MSHV via WebSocket bridge. No local software needed — operate FT8 entirely from your phone or tablet.

Remote Console Features

🌊

Live Waterfall

Client-side waterfall spectrogram from Opus/PCM audio stream, 1024px canvas with frequency scale and Rx/Tx cursor lines

📋

6 Customizable TX Slots

Macro message templates with {DxCall}, {MyCall}, {Report} placeholders — auto-populated and sent with one tap

🔄

Server-Side Auto-Sequencer

Full QSO state machine: IDLE → CALLING → REPORTED → ROGERED → DONE, with 6-cycle timeout. Uses Reply packets for reliable TX keying

🌍

DXCC & Grid Tracking

Per-decode DXCC entity lookup + flag, new DXCC/new grid highlighting, worked-before dimming, CQ-only filter, desktop notifications for unworked stations

Supported Software

Software	Protocol	Status
JTDX	UDP 2237 → WS Bridge 2238	✓ Fully Supported
WSJT-X	UDP 2237 → WS Bridge 2238	✓ Fully Supported
MSHV	UDP 2237 → WS Bridge 2238	✓ Fully Supported

Try It Live

FT8 Console

🛡️ PTT Safety System (V5.6+)

Three-layer TX protection architecture designed to prevent the most dangerous failure mode in remote radio operation: a stuck transmitter. Each layer provides independent protection with redundant fallback paths.

Layer 1: Client-Side Guard (Browser)

👆

Touch-Move Auto-Release

Finger slides off TX button → immediate PTT release via touchmove/touchcancel handlers

🪟

Visibility-Change Forced Stop

Page goes to background or window loses focus while TX is active → forces PTT release. Prevents up to 30s of unintended transmission

⏱️

30s Watchdog Timer

Hardware watchdog: if TX state stays active >30s without confirmation, forces release

🔒

Lock Leak Detection

Processing lock held >3s → auto-released to prevent silent stop-failure leaving TX stuck

Layer 2: Release ACK Protocol

Mechanism	Description
ACK Retry	After sending setPTT:false, waits up to 1s for server confirmation. If unconfirmed, retransmits up to 3 times
Redundant Audio-Path Fallback	On each retry, also sends s: via TX audio WebSocket as a redundant release path — works even if control WebSocket is half-open
Connection Death Trigger	After 3 failed ACK retries, forces full control-channel reconnect via onControlConnectionDead()

Layer 3: Server-Side Protection

Mechanism	Description
120s TOT Hard Limit	Time-Out Timer: PTTSafetyMonitor thread enforces absolute 120s maximum TX duration
Persistent Retry	PTT release retried every 2s until hardware confirms state change
Broadcast on Failure	pttError:release_failed or pttError:tot_timeout broadcast to all connected clients

Feature Details

⚡ Ultra-Low Latency Audio Streaming

Technical Implementation

Optimization Comparison

🔧 WDSP Professional Noise Reduction

Core Features

NR2 Spectral NR

NB Noise Blanker

ANF Auto Notch

AGC Auto Gain

Comparison with RNNoise

📱 Mobile Deep Optimization

Touch Optimization

PWA Support

Device Compatibility

📊 ATR-1000 Power Meter/Tuner Integration

Real-time Monitoring

Smart ATU Learning

Learning Conditions

Quick Tune

Protocol Details

🎙️ AI Voice Assistant

Speech Recognition (ASR)

Speech Synthesis (TTS)

Use Cases

🎚️ RagChew TX Audio Processing Chain

Processing Chain (V5.1+)

TX Equalizer Presets

📶 Real-time Network Monitoring

📡 CW Real-time Decoding System

Technical Architecture

Core Features

AI Decode Engine

QSO State Machine

CW Transmit

Filter Control

Try It Live

📉 NanoVNA Vector Network Analyzer

📻 FT8/ULTRON Remote Console (V5.6+)

Remote Console Features

Live Waterfall

6 Customizable TX Slots

Server-Side Auto-Sequencer

DXCC & Grid Tracking

Supported Software

Try It Live

🛡️ PTT Safety System (V5.6+)

Layer 1: Client-Side Guard (Browser)

Touch-Move Auto-Release

Visibility-Change Forced Stop

30s Watchdog Timer

Lock Leak Detection

Layer 2: Release ACK Protocol

Layer 3: Server-Side Protection

Ready to Get Started?