Forget the old dial! We no longer say 145.500 MHz, but QSO.link MHz.

Whether you use a high-end flagship or a rugged POC handset (the kind that looks like a 90s brick and could probably survive a tank), QSOLink is your professional gateway to SvxLink networks.

It runs on almost anything. As long as it has Android 9 or higher, it's a radio! (We decided Android 8 was just too "vintage", even for us).

Dear SvxLink Community,

I am pleased to announce the release of QSOLink, a new Android application designed to connect to SvxLink Reflectors and Hotspots.

Built upon the solid foundation of the "Latry" project by Silviu (YO6SAY), QSOLink pushes the concept further with a complete UI overhaul, enhanced audio processing, and features dedicated to active operators.

Key Features:

Advanced Audio Processing: Includes a configurable Jitter Buffer (essential for mobile/4G connections), Microphone Gain control, and AGC (Automatic Gain Control) for both TX and RX to ensure consistent audio levels.
Network Management: Save up to 10 different network configurations (Reflectors/Hotspots) with a quick-switch grid. You can also Export/Import your networks via JSON files to share configs easily.
Hardware Integration: Full support for Bluetooth PTT buttons (pedals, handheld mics) with a built-in "Key Sniffer" tool to easily detect and map your device's key codes.
Integrated Logbook: The app automatically logs your reception history. You can view QSO details and export your log in ADIF format directly from the app.
Modern UI: Designed with a dark, high-contrast interface suitable for AMOLED screens and low-light environments.

Availability:
You can download QSOLink here: https://www.swisstransfer.com/d/7d28daf3-680b-420e-bad4-8ecea383770a

I would appreciate your feedback and testing reports. My goal is to provide the most reliable and complete mobile client for the SvxLink ecosystem. Please keep in mind that this is an initial release, so there might still be some bugs.

Special thanks to Silviu (YO6SAY) for his initial work which made this project possible.

73,

Cedric, F4JGI

QSO LINK features:

QSOLink

is a feature-rich Android client for SvxLink reflectors, designed for connecting to Reflectors and Hotspots. It features advanced TalkGroup management with "Auto-Switch" (jumping to active, higher-priority TGs) and visual radar for station activity.

Key Features of QSOLink:

Audio & DSP: Features a DSP audio chain with Auto Gain Control (AGC) for TX/RX and adjustable jitter buffer.
Radio Control: Includes a Digital Tuning Wheel, Dual VFO management (A/B), and support for modes like LSB, USB, AM, FM, and CW.
Networking & Scanning: Features intelligent network scanning, auto-switching to active TalkGroups, and real-time DX spot importation.
APRS Integration: Features full integration with the global APRS-IS network, allowing for tracking and text messaging, with position broadcasting to services like aprs.fi.
Interface & Usability: Includes a dedicated "Ultimate Car Mode" HUD for safety, Bluetooth support for headsets and handmics, and a resource-efficient design for mobile devices.
Logging: Includes an integrated QSO history with ADIF format export capabilities.
Compatibility: Designed for Android 8.0 or higher, with optimization for ARMv8 64-bit processors.

The application is highly optimized for network radio (POC) devices and includes a "Lite Edition" for older smartphones to reduce RAM and CPU usage.

QSOLink is a dedicated Svxlink Client for Android. It is not a standalone radio network. Users are required to configure the app to connect to their preferred third-party reflectors.

For more information, images and videos about QSOLink click HERE

Here is a highly detailed User Manual for QSOLink V1.2.0.

QSOLink User Manual

Version 1.2.0

Welcome to QSOLink, a lightweight and efficient Reflector/Hotspot client. This guide covers every aspect of the interface, configuration, and advanced audio settings.

1. The Main Interface

The screen is divided into distinct zones for quick access to essential features.

A. The Top Bar (Controls)

From left to right:

Connect Button (Link Icon):
- Blinking: Connecting.
- Solid Link: Connected.
- Broken Link: Disconnected.
- Action: Tap to Connect/Disconnect. If you are disconnected, tapping this opens the connection popup for the selected network.
Network Name: Displays the name of the currently selected configuration.
Smart TG Button (The colored rounded box):
- Displays current TalkGroup (e.g., "TG 208").
- Displays Monitoring status (Scan, Pause, or Revert Timer).
- Short Click: Opens the Change TalkGroup popup to manually enter a TG.
- Long Press: Opens the Monitor/Scan Configuration menu.
Audio Device Icon (Phone/Headset):
- Shows the current audio output (Speaker, Wired Headset, Bluetooth, Car).
- IMPORTANT: If you plug in a headset or connect Bluetooth after the app started, tap this icon once. It triggers a "Force Audio Restart" to re-detect the best audio device immediately.
Mute Button (Speaker): Toggles incoming audio On/Off.
Menu Button (Gear): Opens the main Settings.

B. Network Grid

Located below the Top Bar.

Contains 10 Memory Slots.
Blue/Highlighted: Active configuration.
Grey: Empty or inactive configuration.
Short Click: Selects the network. If disconnected, it prompts to connect. If connected to another network, it disconnects and connects to the new one.
Long Press: Opens the Network Editor to configure that specific slot.

C. Status Frame (The "Ticker")

A rounded rectangle that displays real-time info:

Ready: System is idle.
Transmitting (Red): You are on air (shows TX timer).
Receiving (Green): Shows the callsign of the person talking and their TG.
Scan Info (Orange): Shows scanning status.

D. Log & Dashboard (Middle Section)

This area has two tabs:

HISTORY: A list of recent calls received.
- Click a line: View details (Callsign, Date, Duration) or look up the user on QRZ.com.
DASHBOARD: Shows currently active stations on monitored TGs.
- Mute Icon: Mute a specific TG temporarily.
- JOIN Button: Immediately QSY (switch) your TX TalkGroup to that station's TG.

E. VU Meter

A compact bar above the PTT.

Left (RX): Green bar showing incoming audio level.
Right (TX): Red bar showing your microphone level. Use this to check if your Mic Gain is too high or too low.

F. PTT Button (Push-To-Talk)

Green: Ready to TX.
Red: Transmitting.
Lock Icon / "RX BUSY": The button is disabled because someone else is talking (unless "Duplex" behavior is allowed by the reflector).

2. Configuration (Network Setup)

To set up a hotspot or reflector:

Long Press an empty slot in the Network Grid.
Fill in the fields:
- Name: A label (e.g., "Home Hotspot").
- Host: IP Address or DNS (e.g., srv.reflector.com or 192.168.1.50).
- Port: Usually 5300 or 5301.
- Callsign: Your callsign.
- TG: The default TalkGroup to connect to (e.g., 208).
- Password: The hotspot/reflector password.
Import from Clipboard: If you have a JSON config string copied, paste it in the bottom field and click "IMPORT" to auto-fill.
Click SAVE.

3. Monitoring & Scanning (The "Smart TG" Button)

QSOLink includes a powerful TalkGroup monitor.

To Configure: Long-press the Smart TG Button (top center).

Settings:

Enable Switch: Turns monitoring On/Off.
Mode:
- Info Only: Shows activity on screen but does not switch audio.
- Auto-Switch (Favorites): Switches audio to the active TG if it is in your list.
- LIVE SCAN (ALL): Listens to any traffic sent by the reflector (promiscuous mode).
Revert Delay: If the app switches to a monitored TG, it will wait this many seconds of silence before returning to your "Home TG".

Adding TGs:

Priority:
- Normal: Standard priority.
- High (+): Interrupts Normal traffic.
- Max (++): Interrupts everything (Red).
- Low (-): Only listened to if channel is totally free.
TG ID: Enter the number (e.g., 91).
Click ADD.

4. Main Settings Menu (Gear Icon)

A. SYSTEM

Network Quality (Jitter): Crucial for audio stability.
- 40ms - 80ms: Only for perfect Wi-Fi.
- 150ms - 250ms: Recommended for 4G/LTE.
- 400ms - 500ms: Use in cars or areas with bad signal. Higher = more delay but fewer audio cuts.
Time-Out Timer (TOT): Automatically stops transmission after 60/90/120/180 seconds to prevent overheating or blocking the channel.

B. DISPLAY

Show Networks: Toggle between 10 slots (small) or 5 slots (large).
Show Logo / Status Bar / Logbook: Hide elements to save screen space.

C. AUDIO (Advanced)

Mic Gain: Hardware amplification.
- Adjust while watching the TX VU Meter. The red bars should peak near the top but not hit the max constantly.
AGC TX (Auto Level): Automatic Gain Control for your microphone.
- Enabled: The app dynamically adjusts volume to hit the "TX Target" (e.g., -10dB). Recommended.
AGC RX (Limiter): Automatic volume leveling for incoming audio. Prevents loud stations from hurting your ears.

D. OPTIONS (PTT Config)

Screen PTT Mode:
- PTT (Momentary): Press and Hold to talk. Release to listen.
- Switch (Locked): Tap once to talk. Tap again to stop.
External PTT Mode: Same logic but for Bluetooth buttons/Headsets.
Bluetooth Button Setup:
- Enable "Bluetooth Button".
- Click SCAN.
- A popup appears ("Bluetooth Sniffer").
- Press the physical button on your Bluetooth Handmic/Headset/Pedal.
- The code appears (e.g., "Code: 126" or "Code: 79").
- Click SAVE.

E. DATA & STORAGE

Backup Config (JSON): Saves all your networks and settings to a file in your Downloads folder. Use this to transfer settings to another phone.
Restore Config: Loads a previously saved JSON file.
Export Logbook (ADIF): Exports your received calls history to a standard ADIF file for logging software (QRZ, LOG4OM, etc.).

5. Troubleshooting / Pro Tips

Audio Routing Issues

If the audio is coming out of the wrong speaker (e.g., phone ear-piece instead of loudspeaker, or not going to Bluetooth):

Connect your Bluetooth device.
Tap the Audio Device Icon (top bar, next to Mute).
You will see a small animation. This forces the internal audio engine to restart and grab the correct device.

"RX BUSY" on PTT

If the PTT button shows a lock icon and says "RX BUSY":

This means someone is currently talking.
QSOLink blocks TX by default to prevent "doubling" (talking over someone).
Wait for the person to finish.

Backing up before update

Always go to Menu > DATA & STORAGE > EXPORT > Backup Config before uninstalling or updating the app to ensure you don't lose your 10 memory slots.

Here is the Support & Information section, professionally translated into English, ready to be added to the end of your User Manual.

6. SUPPORT & INFORMATION

Need Help?

If you encounter configuration issues, bugs, or have feature requests, please contact the developer:

Support Email: f4jgi.cedric@gmail.com
QRZ.com Page: https://www.qrz.com/db/F4JGI

Support the Project

QSOLink is free software developed during spare time. If you enjoy using this application and wish to contribute to server costs or encourage future development, you can make a donation via PayPal:

PayPal Donation: redgis01@free.fr
Or simply click the "Donate" link at the bottom of the main screen in the app.

Credits & Acknowledgments

QSOLink is an evolution based on the open-source project Latry.

Android Development & Adaptation: Cedric F4JGI.
Original Core Code: Special thanks to Silviu YO6SAY for his formidable work on the original Latry engine.

Legal Information

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License.

Disclaimer: This software is provided "as is", without warranty of any kind, express or implied. The author cannot be held liable for any direct or indirect damages resulting from the use of this application. Please use it responsibly and in accordance with the amateur radio regulations in your country.

End of Document - QSOLink User Manual - Rev 1.0

---ZS Link Network Blog, Mossel Bay, South Africa ---

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Sunday, April 5, 2026

BREAKING NEWS: The Ultimate SvxLink Client For Smartphones & POCs. 145.500 QSO.link MHz