Wojciech Kaczmarski is a Polish engineer working in digital communications and software-defined radio systems, contributing to the development of open digital radio protocols and open-source radio platforms, including work on the M17 digital voice project.
Work on open-source radio systems Kaczmarski's work has focused on the development of open-source software and hardware for digital radio communications. His projects have emphasized openly published specifications, permissive licensing, and community-driven development within amateur and experimental radio environments.
As part of this work, he has published technical articles addressing signal processing and waveform design for modern digital radio protocols.
Elements of this work have been presented and discussed at technical amateur radio conferences, including those organized by Tucson Amateur Packet Radio.
M17 protocol development Kaczmarski has contributed to the development of the M17 digital voice protocol, an open digital radio protocol intended for amateur radio use. The project has been discussed within amateur radio and technical communities as an alternative to proprietary digital voice systems and has been presented at technical and amateur radio events.European GNU Radio Days 2023 (abstracts).WB0IIS, George Schindler. Open-source digital radio made by and for amateur radio, Missouri Digital Group.Poole, Ian. M17 Digital Voice Mode for Amateur Radio. Electronics Notes.
M17-related work has been presented at international amateur radio and technical events,Software Defined Radio Academy 2022 Programme.Kurt Baumann. M17 - Open Source Radio. Österreichische Versuchssenderverband (ÖVSV). including those supported by the International Amateur Radio Union.
LinHT transceiver development Kaczmarski has also worked on open-source radio hardware.M17 Announces New Open-Source Hardware for Amateur Radio Enthusiasts and Enhancements to Current Offerings Amateur Radio Digital Communications.M17 open source radio Dangerous Prototypes. He has contributed to the development of LinHT, a handheld software-defined radio transceiver intended to support open digital communication systems.LinHT - Technological Innovation In Amateur Radio, Zero Retries 0215 The project has been described in amateur radio and technical media,LinHT – Open SDR Handheld for Radio Amateurs, uart.czLinHT for Beginners: A Linux-Based Experimental SDR Radio, EvoHamLinHT Progress, k0tfu.org including a cover feature in the German amateur radio magazine CQ DL, and has been included in the program of technical conferences such as OpenAlt 2025 in Brno.OpenAlt - schedule
Other work In addition to his contributions to digital radio protocols, Kaczmarski has participated in work on longwave broadcast time signals. In 2023-2024, he and co-author Grzegorz Kaczmarek examined the PCSK225 phase-modulated time code transmitted on Poland's 225 kHz longwave broadcast signal, Polskie Radio Program I, and implemented an open-source decoder based on publicly available documentation. Their work clarified details of the signal format and associated error control codes.New timecode on Poland's 225 kHz signal
Adoption and technical discussion Work associated with M17 and related platforms has been implemented in experimental and commercial radio equipment and has been the subject of technical discussion in amateur radio and software-defined radio communities.
Independent publications have examined the design goals and implementation of these systems in the broader context of open digital radio development.
Awards and recognition In 2021, Kaczmarski received the ARRL Technical Innovation Award from the American Radio Relay League for his work on open digital radio communications.
Presentations and events Topics related to Kaczmarski's work have been presented at technical conferences and amateur radio events, including meetings organized by IEEE chapters"Practical open source engineering" - San Diego Section Chapter, IT12Bournival, Erin. "International Standardization and M17" - San Diego Section Chapter, IT12 and amateur radio organizations, as well as academic and educational venues. This has included participation in activities associated with HamSCI, focusing on the use of open digital radio technologies in educational and experimental contexts.
Interviews and media coverage Kaczmarski has appeared in interviews and media coverage discussing open-source digital radio development. Coverage has included interviews conducted by independent bloggers, amateur radio publications, and broadcast media in multiple countries.
Reception and commentary Commentary on Kaczmarski's work has appeared in technical and amateur radio media, focusing on open-source approaches to digital voice protocols and software-defined radio platforms. Coverage has included both descriptive and critical discussion of design choices and implementation strategies.K8JTK, Jeffrey Kopcak. Ohio Section Journal – The Technical Coordinator – August 2025 edition. ARRL Ohio Section
See also Open-source software Codec 2
References