FSQ overview and international band-plan

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FSQ (Fast Simple QSO) is a digital communication mode designed for fast, keyboard-to-keyboard chatting on HF and VHF/UHF amateur bands. It was developed by Murray Greenman ZL1BPU and Con Wassilieff ZL2AFP, aiming to provide a simple, responsive, and user-friendly mode for real-time communication.

Key Features of FSQ:

Automatic detection and response: Stations can be "pinged" or queried, and can respond automatically with signal reports, location, or other info.

No manual tuning required: FSQ uses a narrow bandwidth (typically ~500 Hz) and can decode signals automatically without needing exact tuning.  

Simple text interface: It's designed for casual chatting—more like instant messaging than traditional ham radio QSO formats.

Supports APRS-like messaging: You can send position reports, beacon messages, and even file transfers.

Good weak signal performance: It works well with low power and under poor band conditions.

How FSQ Works:

Each character is transmitted using a short tone burst (DFT-based), and the system uses 33 tones spaced 16 Hz apart.

Messages are call-directed, meaning you can address a station specifically (e.g., vk6ysf HELLO) or broadcast to everyone.

FSQ uses time-synchronized intervals to listen and transmit, minimizing collisions when multiple stations are active.

Software:

The most common software used for FSQ is FSQCall and FLDigi, available for Windows and Linux. It provides a straightforward interface for chatting, beaconing, and automation features.

Use Cases:

Informal digital chatting on HF.

Typical QSO

A typical FSQ QSO (contact) is more like a casual text chat than a structured exchange. It’s quick, informal, and efficient, ideal for keyboard-to-keyboard chatting. Here's how it usually goes:

1. Calling another station

You start by directing a message:

vk6abc hello

This message is seen by everyone, but only VK6ABC's software will beep and highlight it as directed to them.

2. Replying

If VK6ABC is there, they might reply with:

vk6ysf hi there

3. Exchange of info

You might then exchange signal reports or chat casually:

vk6ysf UR Signal 10dB. running 10w

vk6abc UR 8dB. Rig is a IC-7300 at 25w

4. Ending the QSO

You can end simply with a message like:

vk6ysf TNX QSO 73!

vk6abc 73 CUL

Optional: Automation

FSQ also allows you to:

Send a “ping”: vk6abc? – Their station will automatically reply with signal strength and optionally location.

Beacon automatically every few minutes (e.g., for nets or propagation checking).

Send short files or images (though slow and limited).

Unlike modes like PSK31 or RTTY, FSQ is:

Asynchronous – No need to wait for turn-taking like in structured QSOs.

Flexible – Great for keyboard chat, nets, or automated data sharing.

FSQ Frequencies by Band (USB Mode)

List command characters

The command characters used in FSQ (especially in FSQCall), which allow stations to interact automatically or send special instructions:

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Page initiated 6 May, 2025 

Page last revised 20 May, 2025