Spectrum Art

Desktop application to generate WAV audio for SDR waterfall text/image transmission, with optional CAT/PTT control.

The project is implemented in Python with a Tkinter GUI.

Overview

Spectrum Art converts text or images into audio signals suitable for waterfall visualization and transmission workflows.

Main capabilities:

• Generate WAV from text or image source
• Preview generated output in the waterfall display
• Play audio on a selected output device
• Transmit audio with optional CAT/PTT control
• Save and load user presets
• Save, load, and delete named radio CAT configurations
• Quick message slots for rapid transmission
• Language selection (Italian/English)

Main Control Buttons

• Generate WAV — Generates WAV file from text or image source
• Save WAV — Saves generated WAV to disk (enabled after generation)
• Play — Plays audio through selected audio device (enabled after generation)
• Stop — Stops current playback
• Transmit — Transmits audio via radio CAT/PTT (enabled when radio configured and WAV ready)
• Stop TX — Stops transmission

Quick Message Slots

Six numbered buttons (1-6) for storing and quickly transmitting pre-recorded messages:

• Click a slot number to select and load a saved message
• Use "Store text" button to save current text to selected slot
• Use "Delete slot" button to remove saved message from slot
• Hover over slots to preview stored message content (tooltip)

Features

• Source types:
  • Text (with font rendering options)
  • Image (PNG/JPG/JPEG/BMP)
• Modulation modes:
  • SSB-USB, SSB-LSB
  • AM, FM
  • DATA-U, DATA-L
  • CW
• Adjustable signal parameters:
  • Frequency range (fmin/fmax)
  • ms/column (transmission speed)
  • Sample rate
  • Gain
  • Height
  • Text rendering options (font size, stroke, threshold, spacing, pause)
  • Image options (invert, vertical flip, horizontal flip, rotate 90° left)
• Audio:
  • Device selection dropdown with refresh button
  • Real-time device status indicator
  • Playback and TX use the selected output device
• Radio CAT Control:
  • FTDX-10: CAT read/write + PTT
  • XIEGU (CI-V): CAT read/write + PTT
  • FT-736R: CAT write-only for PTT ON/OFF
  • Connection status indicator
  • Read from radio / Sync parameters buttons
  • Port refresh button
• Presets:
  • Save all signal parameters with custom name
  • Load saved presets
  • Delete presets
• Radio Profiles:
  • Save radio/audio device configuration with custom profile name
  • Load previous radio configuration
  • Delete saved profiles

Installation — Linux

Requirements: Python 3.9+ with python3-venv, python3-pip, python3-tk, and libportaudio2.

Automatic setup (Debian/Ubuntu)

git clone https://github.com/aleiei/rf_spectrum_art.git
cd rf_spectrum_art
bash setup.sh

setup.sh installs the required system packages via apt (with sudo if needed), creates a local venv/ virtual environment, and installs all Python dependencies from requirements.txt.

Run

bash run.sh

Or manually:

source venv/bin/activate
python rf_spectrum_art_cat.py

Manual setup (other distros)

Install system dependencies for your distro (e.g. python3-venv, python3-tk, portaudio), then:

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python rf_spectrum_art_cat.py

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Installation — Windows

Requirements: Python 3.9+ for Windows from python.org (check "Add Python to PATH" during install).

Setup venv

Open a Command Prompt or PowerShell in the project folder:

python -m venv venv
venv\Scripts\activate
pip install -r requirements.txt

Run

venv\Scripts\activate
python rf_spectrum_art_cat.py

Pre-built executable (Windows)

A pre-built standalone executable is available in the rf_spectrum_art_cat_windows/ folder:

rf_spectrum_art_cat_windows\rf_spectrum_art_cat.exe

No Python installation required — just run the .exe directly.

Note: Windows Defender or SmartScreen may flag unsigned executables. If prompted, choose "Run anyway" or add an exclusion.

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Dependencies

Python packages (see requirements.txt):

• numpy
• pillow
• pygame
• pyserial
• sounddevice

System packages on Debian/Ubuntu:

• python3-venv
• python3-pip
• python3-tk
• libportaudio2

Project files

• rf_spectrum_art_cat.py — main application
• run.sh — run script using local virtual environment (Linux)
• setup.sh — setup script for venv and dependencies (Linux/Debian)
• requirements.txt — Python dependencies
• build_windows_exe.sh — builds Windows .exe from Linux via Wine
• rf_spectrum_art_cat_windows/ — pre-built Windows executable
• .rf_spectrum_art_presets.json — user presets (auto-generated)
• .rf_spectrum_art_radio.json — named radio CAT configurations (auto-generated)

Run

1. Setup environment:
   • bash setup.sh
2. Start application:
   • ./run.sh

Radio configuration profiles

In Radio Menu you can:

• Save settings with a custom profile name
• Load one saved profile from a selection dialog
• Delete a saved profile from a selection dialog

Notes

• CAT TX button is enabled only when radio is configured and WAV is available.
• For FT-736R, CAT read/sync is intentionally disabled because only write/PTT is used.
• Transmission speed is mainly controlled by ms/column; lower value means faster transmission.

License

Copyright (C) 2026 Alessandro Orlando

This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0).

You are free to use, modify, and distribute this software under the terms of the AGPL-3.0. If you run a modified version as a network service, you must make the complete source code available to users.

See the LICENSE file for the full license text, or visit https://www.gnu.org/licenses/agpl-3.0.html.