contest-sdr

Author: Clayton Smith
Email: [email protected]

The intent of this project is to turn a transmit-capable SDR board (HackRF, BladeRF, PlutoSDR, USRP, or LimeSDR) into a multi-band transceiver for use in amateur radio contests such as the ARRL June VHF contest. At present it only supports CW.

Usage

Install GNU Radio 3.10 or later. Make sure that SoapySDR support is included, and the SoapySDR driver for your target device is installed. On Ubuntu 22.04, simply run sudo apt install gnuradio to get an appropriate version of GNU Radio, SoapySDR and drivers.

Clone this repository: git clone https://github.com/argilo/contest-sdr.git

From the contest-sdr directory, run one of the following commands:

• ./b200_transceiver.py — USRP B200
• ./blade_transceiver.py — BladeRF
• ./hackrf_transceiver.py — HackRF
• ./lime_transceiver.py — LimeSDR
• ./pluto_transceiver.py — PlutoSDR

Each of these scripts ties together the corresponding <device>_rx (receive) and <device>_tx (transmit) flow graphs, which are built with GNU Radio Companion. The GUI is part of the receive flow graph.

When the application starts it will be in calibration mode, which uses the pilot tone of ATSC channel 33 (584.309441 MHz) to help adjust the PPM correction value. Adjust the PPM setting up or down until the pilot signal is at 100 kHz in the upper (IF) waterfall, and at 700 Hz in the lower (audio) waterfall.

Next, select the band you would like to transmit on. Adjust the receive and transmit gains as desired. The audio scope (lower right) shows the received audio signal. If clipping occurs, reduce the receive gain.

To transmit CW, type your message into the "CW to send" box and press enter. Once transmission is complete, the box will empty and the receive waterfalls will start running again.

Building a bootable USB flash drive

On an Ubuntu system:

• Download https://releases.ubuntu.com/jammy/ubuntu-24.04-live-server-amd64.iso and place it in ~/Downloads/
• Install the dependencies: sudo apt install qemu-system-x86 ovmf
• Generate the live USB images: liveusb/create.sh
• At the prompt, enter your password to allow the Ubuntu ISO to be mounted
• Write an image to a flash drive (16 GB or larger): sudo dd if=liveusb/contest-sdr-uefi.img of=/dev/sdb bs=4M conv=fsync

Boot from the flash drive and double click the "Contest SDR" icon on the desktop corresponding to your SDR device.

For old systems that don't support UEFI, the contest-sdr-bios.img image can be flashed instead.

License

Copyright 2015-2024 Clayton Smith

This file is part of contest-sdr

contest-sdr is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

contest-sdr is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with contest-sdr; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Boston, MA 02110-1301, USA.