HamLink - Professional VoIP PTT for Amateur Radio

Engineered for Performance

Professional-grade features for demanding amateur radio operators

🎚️

Studio-Grade Audio

iPhone-quality TX DSP chain with high-pass filters, presence boost, compression, and brick-wall limiting. Wideband 8kHz Opus codec for exceptional voice clarity.

Per-device microphone gain (0-50dB)
Real-time VU meters for TX/RX monitoring
Standard (20kb/s) & High (32kb/s) quality modes

⚡

Ultra-Low Latency

Optimized audio pipeline with ARM NEON acceleration. ~21ms TX latency, ~150ms RX latency with adaptive jitter buffering.

Hardware-accelerated sample rate conversion
Lock-free circular buffers
SVXLink-compliant jitter FIFO

📡

Multi-TG Support

Monitor multiple talkgroups simultaneously with priority-based auto-selection. Quick profile switching for ADVANCED tier users.

Up to 10 connection profiles
Priority-based TG selection
Auto-return to default TG with timeout

🔧

Flexible Configuration

Extensive customization options for PTT modes, audio routing, and network settings. Background operation with foreground service.

Push-to-Talk or Toggle modes
Transmission Time-Out Timer (TOT)
Sticky manual audio device selection

🛡️

Robust & Reliable

Battle-tested SVXLink protocol implementation with automatic reconnection, network change detection, and packet loss concealment.

Auto-reconnect on network changes
HMAC-SHA1 authentication
Opus PLC for seamless recovery

🎯

Device Ecosystem

Automatic detection and per-device audio optimization. Supports internal mic, wired headsets, Bluetooth, and Android Auto.

Auto audio focus management
Per-device gain profiles
Seamless device hot-swap

Global Compatibility

Connect to SVXLink reflectors worldwide and integrate with diverse radio systems

🌍

Worldwide SVXLink Network Access

HamLink is fully compatible with SVXLink reflectors and servers globally, giving you instant access to thousands of amateur radio nodes, repeaters, and hotspots around the world. Built on the industry-standard SVXLink protocol, HamLink seamlessly integrates with existing infrastructure.

🔗 TETRA Integration

Connect to TETRA networks through SVXLink bridges, enabling professional-grade trunked radio system access

📞 EchoLink Gateways

Access EchoLink nodes via SVXLink EchoLink modules, bridging VoIP and traditional amateur radio

📡 Repeater Networks

Connect to analog FM repeaters and digital DMR/D-STAR/Fusion repeaters through SVXLink gateways

🌐 Multi-Protocol Bridges

Seamlessly communicate across analog and digital systems through SVXLink's bridge infrastructure

🎯 Universal Protocol Support: Works with any SVXLink-compatible reflector, regardless of backend system (TETRA, Analog, DMR, D-STAR, Fusion, AllStar, or hybrid networks)

Technical Specifications

Audio Engine

Codec	Opus (16kHz native)
Bitrate	20kb/s (Standard), 32kb/s (High)
Audio Bandwidth	6kHz (Standard), 8kHz (Wideband)
TX Latency	~21ms (end-to-end)
RX Latency	~150ms (with jitter buffer)
Sample Rate Conversion	High-quality FIR filter
DSP Chain	HPF, Pre-emphasis, Limiter, LPF

Network Protocol

Protocol	SVXLink-compatible
Control	TCP with HMAC-SHA1 auth
Audio	UDP with QoS (DSCP EF)
Multi-TG	Priority-based auto-selection
Auto-Reconnect	Network change detection
Packet Loss	Opus PLC for recovery

Platform Support

Android Versions	6.0 (Marshmallow) - 16
API Level	23 - 35
Architectures	ARM64, ARMv7, x86-64
SIMD Acceleration	ARM NEON, x86 SSE2
Audio Framework	Oboe (low-latency)
UI Framework	Jetpack Compose

License Tiers

All tiers include full core functionality. Support development and unlock expanded limits for multi-profile workflows.

FREE

All Core Features

✓ Studio-grade audio processing

✓ Ultra-low latency (~21ms TX)

✓ SVXLink protocol support

✓ Transmission Time-Out Timer (TOT)

✓ Notifications with Callsign on lock screen

✓ Background operation

📋 2 Connection Profiles

📱 1 Device

PRO

Support Development

1 Coffee ☕

Everything in FREE, plus:

📋 5 Connection Profiles

📱 3 Devices

Support bug fixes & updates

Activate: Email from BuyMeACoffee.com

ADVANCED

Power User

3 Coffees ☕☕☕

Everything in PRO, plus:

📋 10 Connection Profiles

📱 5 Devices

⚡ Quick Profile Switching

📡 Multi-TG Monitoring

Priority support for new features

Activate: Email from BuyMeACoffee.com

💙

Your support helps maintain HamLink, fix bugs, and add new features. No subscriptions, no ads, just one-time support via BuyMeACoffee.com. Activate with your BMC email address.

ℹ️

Touchscreen Safety: PTT and Settings buttons require a 0.5 second press to prevent accidental activation. D-pad/keyboard input activates instantly.

Audio Pipeline Architecture

TX Path (~21ms)

📱 Microphone

→

🎛️ DSP Chain

→

🔄 SRC (48→16kHz)

→

🎙️ Opus Encode

→

📡 UDP Network

RX Path (~150ms)

📡 UDP Network

→

🎙️ Opus Decode

→

📦 Jitter FIFO

→

🔄 SRC (16→48kHz)

→

🔊 Speaker

See It in Action

Modern Material Design 3 interface with real-time audio visualization

Main Radio Interface - TX

Large PTT button with real-time VU meters showing TX and MIC levels

Main Radio Interface - RX

Incoming caller identification with signal strength visualization

Profile & License Management

Multi-profile support with license tier display and device management

Application Settings

Flexible PTT modes, Time-Out Timer, background operation controls

Advanced Audio Settings

Per-device microphone gain control with wideband quality options

Ready to Get Started?

Download HamLink for Android and experience professional-grade VoIP PTT communication.

✓ Free to download and use
✓ Compatible with Android 6.0+
✓ SVXLink protocol support
✓ No ads, no tracking

Google Play Download APK (v2.0.1 Preview)

Direct APK download available now • Google Play coming soon