Professional IP Voice Communications — Anywhere. Anytime.
Push-to-talk voice linking over local networks and the internet. Built for radio operators, remote sites, and anyone who needs a reliable communications link.
ComLink v3 is a professional push-to-talk voice communications platform designed for operators who need reliable, low-latency audio links over any network. Whether linking radio repeaters across a region, monitoring remote antenna sites, or coordinating field teams — ComLink delivers.
It runs on Windows PCs, Raspberry Pi single-board computers, and Android phones. A lightweight Pi-specific build handles headless relay nodes at remote sites. The full desktop app adds HF radio CAT control, an analog S-meter, band scope, AI noise suppression, VOX, AGC, and a professional TX audio processing chain.
ComLink v3 uses a central relay server for multi-party communications. All clients connect to the server which handles audio routing, channel arbitration, peer announcements, and registration. No complex peer-to-peer configuration required.
ComLink combines voice, radio control, audio processing, chat, and network management into a single focused application.
Spacebar toggle PTT with ON/OFF buttons and a large visual ON-AIR indicator. Serial hardware PTT via RTS or DTR for direct radio interface connections.
Broadcast-quality Opus codec at 48kHz mono. Selectable bitrate: 24 / 32 / 48 / 64 / 96 kbps. Forward error correction and packet loss concealment built in.
Automatic transmit when mic audio exceeds the threshold. Adjustable threshold (0–100%) and hang time (100–2000ms) — ideal for hands-free operation or squelch-driven radio linking.
Central Raspberry Pi relay routes Opus audio to all connected clients. Manages HELLO registration, first-keyed-wins channel arbitration, peer announcements, and welcome audio for new connections.
Automatic peer discovery on local networks via UDP multicast (239.192.0.1:5198). Multiple stations find each other and connect instantly — no IP address entry needed.
Full PTT client for Android. 48kHz Opus, same protocol as the desktop. Detects server loss automatically and prompts to reconnect. Works on LTE, 5G, or Wi-Fi.
Professional microphone chain: AI Denoise (RNNoise neural network), Auto Gain Control, Noise Gate, and Low-Cut Filter (50–300 Hz). All applied before encoding, in the correct signal order.
Full CAT control for Icom, Yaesu, Kenwood, and Elecraft HF radios. Tune frequency, change mode, and read the S-meter. Auto-detect identifies your radio automatically.
Calibrated analog needle S-meter reads signal strength from CAT-connected radios in real time. Visual band scope with click-to-tune and band buttons (160m–6m) with automatic mode switching.
Lightweight Tkinter build for Raspberry Pi relay nodes. 5–10% CPU. Serial PTT and COS detection for radio interfaces. Deploys headless at remote sites — no Qt or monitor required.
Real-time text chat between all connected stations on a dedicated port (52000 UDP), independent of the audio channel — chat while audio is in use.
Your relay server, your rules. No cloud accounts, no subscriptions, no data sent to third parties. All audio stays on your own infrastructure.
ComLink connects directly to your HF transceiver via CAT — tune frequency, change mode, and read the S-meter without touching the radio.
Any radio that appears as a COM port in Windows Device Manager will work. Supported interface hardware includes Icom OPC-478/589, SignaLink USB, RigBlaster, DigiRig, Yaesu SCU-17/SCU-20, and any USB-to-serial adapter connected to the radio's ACC or CAT port.
FlexRadio FLEX-5000 / PowerSDR is supported via VB-Audio Virtual Cable (audio) and com0com virtual serial pair (CAT).
From amateur radio operators to emergency communications teams — ComLink fits wherever reliable voice links are needed.
Link VHF, UHF, and HF stations across cities or regions. Bridge repeaters over IP. Control your HF rig remotely via CAT while monitoring the S-meter.
Deploy a Pi Lite node at a remote antenna or repeater site. Monitor and operate equipment from anywhere over DDNS or Tailscale VPN.
Establish reliable backup voice links when traditional infrastructure is unavailable. Operates over any internet connection including LTE hotspots.
Connect geographically separate repeater sites into a single linked system using low-cost Pi Lite nodes at each location with serial PTT and COS.
Android app lets operators join from anywhere. Full PTT voice on LTE or Wi-Fi. Server-loss detection keeps the app in sync with network status.
Build a closed, private voice network for a club, organization, or team — completely independent of any public service or cloud infrastructure.
ComLink v3 is engineered for reliability and low latency on modest hardware.
| Specification | Detail |
|---|---|
| Audio Codec | Opus — 48kHz mono, forward error correction and packet loss concealment enabled |
| Bitrate (selectable) | 24 / 32 / 48 (default) / 64 / 96 kbps — changes take effect immediately, no restart required |
| Frame Size | 20ms — 960 samples per frame at 48kHz |
| Transport Protocol | UDP — low latency, no buffering overhead |
| Packet Format | 2-byte ComLink header (0xC0 0x00) + Opus payload |
| Jitter Buffer | Adaptive (auto 60–500ms based on measured jitter) or manual (20–500ms) |
| TX Audio Processing | Low-Cut Filter (50–300 Hz) → AI Denoise (RNNoise) → Noise Gate → AGC (up to 8× / 18 dB) |
| PTT Modes | Keyboard (Spacebar), VOX, Serial RTS/DTR, ASCII PTT, External VOX, Android touch |
| RX Modes | Manual, VOX, Serial CTS, Serial DSR, CAT Squelch (S-meter level) |
| CAT Control | Icom CI-V, Yaesu CAT, Kenwood CAT, Elecraft (Kenwood-compatible) — auto-detect |
| DTMF | Standard 16-tone keypad (0–9, A–D, *, #) |
| LAN Discovery | UDP Multicast 239.192.0.1 — automatic, no configuration or port forwarding needed |
| Channel Policy | First-keyed wins, 600ms auto-release on silence |
| Supported Platforms | Windows 10/11 (ComLink3), Raspberry Pi OS 64-bit (ComLink Pi Lite), Android (ComLink App) |
| Recommended Pi Hardware | Raspberry Pi 4 (2GB+ RAM) or Pi 5 — Pi 3 for lite node only |
| Remote Access | Static IP, DDNS hostname (e.g. No-IP), or Tailscale VPN |
| GUI Framework (Desktop) | PySide6 (Qt 6) — native Windows look and feel |
| GUI Framework (Pi Lite) | Tkinter — minimal CPU, no Qt dependency |
A basic multi-station link requires no complex configuration — set up the relay server, install ComLink, and talk.
Run comlink_server.py on a Raspberry Pi. Forward UDP ports 51998, 51999, and 52000 on your router. Use No-IP DDNS for a stable hostname that follows your IP if it changes.
Run ComLink3 on Windows, ComLink Pi Lite on a relay site Pi, or install the Android app on your phone. Enter your callsign and the server DDNS address.
Click Connect (or Enable WAN TX). Wait for "Connected" confirmation from the server. Press Spacebar or the PTT button — your link is live with broadcast-quality Opus audio.
Have questions about ComLink, interested in getting started, or want to learn more?
We would love to hear from you.
We typically respond within 24 hours.
Beta Testing In Progress
ComLink v3 is currently in active beta testing. We are working hard to ensure a solid, reliable release for all platforms. Check back here for the official release date announcement.
Page updated: April 2026 • Release date: Coming soon — stay tuned.