M17 Project

News feed

  • LinHT – an interview with the development team

    LabCat (Tobias DL3MHT) uploaded his interview with the LinHT development team: Wojciech SP5WWP, Vlastimil OK5VAS, and Andreas OE3ANC. Check it out šŸ™‚

  • Friedrichshafen ham radio fair 2026

    Our team spent three amazing days at the HAM Radio Friedrichshafen event. We had a real lot of traffic. Thank you for stopping by and for all the questions that you had! Big shout out to DARC guys, especially Jann Traschewski DG8NGN, for providing space for our booth.

    M17 Foundation attendees:

    • President of the Board – Olha (no callsign yet)
    • Wojciech SP5WWP
    • Jacek SQ5BPF
    • Andreas OE3ANC
    • Vlastimil OK5VAS

    OpenRTX booth:

    • Silvano IU2KWO
    • Marco DM4RCO
    • Morgan ON4MOD
    Image
    Image
    Image
    Our friends – OpenRTX!

  • LinHT Rev B status: what works, what broke, and why Rev C is next

    LinHT Rev B status: what works, what broke, and why Rev C is next

    Before Friedrichshafen, we want to put the current LinHT development status in one place. We have published many short updates over the last months, and the project moved through several phases: Rev A proof-of-concept testing, Rev B design, manufacturing, first boot, RF tests, audio bring-up, GNSS debugging, and now Rev C planning.

    This post summarizes that progress. It starts with what Rev A proved, then goes through what we changed in Rev B, how we built the first boards, what worked during testing, what failed, and what we need to fix before Rev C.

    If you want the longer background, start with my older text about the first LinHT prototype: LinHT – Open SDR Handheld for Radio Amateurs. That article describes the Rev A board, the Retevis C62 donor-radio approach, and the basic idea behind LinHT: a Linux-based SDR handheld transceiver, open enough that the radio can be changed in software, not only programmed from a vendor tool.

    Rev A was our proof of concept. It showed that the architecture made sense and that the device could work the way we imagined. An i.MX93 system-on-module could boot Linux inside a handheld radio body, run a Yocto image, expose USB networking, talk to the display, run GNU Radio flowgraphs, and use the SX1255 IQ RF front end. We decoded M17, tested TETRA receive, displayed spectrum data on the small screen, and ran enough hardware and software tests to be sure that the concept was valid.

    Rev B is the revision where we tried to turn that proof of concept into a much more complete handheld.

    (more…)

  • LinHT Rev B – GNSS antenna issues

    Vlastimil OK5VAS recently tested the GNSS module. Unfortunately, the module used (Quectel LG77L) does not obtain a fix, even when enabled for 30 minutes, outdoors.

    The most suspicious part, and likely culprit, is the path between the antenna and the module:

    Image
    GNSS module (lower left-hand side, 7x7mm rectangle with pads) and the antenna (top, center) with a copper keep-out zone.

    When measured, S11 (from the GNSS module’s perspective) looks like this:

    Image
    S11 plots for setups with cover (chassis) removed and held in place. Note the approx. 200 MHz difference between L1 frequency and where the dip actually is.

    Many thanks to Martin OK1WPM, who helped measure the antenna path both with the cover removed and with the chassis held in place.

    A quick ad hoc fix before Friedrichshafen ham fair is to place an additional capacitor along the coplanar waveguide:

    Image
    Proposed fix using a 0.75pF series capacitor.

    Some more experimentation is required. Keep your fingers crossed! See you in Germany!

  • mvoice 1.4.2 now available

    News from Tom, N7TAE:

    Version 1.4.2 of mvoice is now available. It pulls the https://m17-project.github.io/hostfiles/M17Hosts.json file to initialize the reflector selection drop-down menu. A GIANT Thank You to Jim N1ADJ for setting this up!

    More details: https://github.com/n7tae/mvoice

  • Getting on the air with the MSEVEN iOS app

    Video by Jeff Scoville, AE5ME.

  • LinHT Rev B – hardware testing status

    It took us some time, but here’s a quick update on where we’re at with the LinHT Rev B hardware tests:

    What‘s working?

    • Variable RF input attenuators
    • RF switch – switching between TX/RX paths
    • RF PA (Power Amplifier) – functional, delivering about 4.5 watts (CW)
    • GNSS connection – UART interface (NMEA)

    Still requires testing

    • GNSS receiver’s antenna path
    • PMU (Power Management Unit) – battery voltage measurements

    Known problems

    • Audio codec IC – reset and IĀ²C communication issues needing a bit of investigation
    • The button below PTT not triggering USB boot sequence correctly
    (more…)

  • OpenRTX v0.4.4 release

    New, M17-related functions include:

    • metadata text transmission and reception
    • packet transmission and reception
    • microphone noise reduction through ADC oversampling (results in a perceptibly better Codec2 behavior)

    More info: https://github.com/OpenRTX/OpenRTX/releases/tag/v0.4.4

  • LinHT rev B – first boot

    Sharing great news from Andreas OE3ANC. Good work, team!

    Image

  • m17-gateway now supports three hardware platforms including SX1255 HAT

    I’m happy to announce release 0.5.0 of my M17 Go tools project at github.com/jancona/m17 with some significant updates!

    Three hardware platforms, full M17 feature support

    m17-gateway now supports three different modem/hardware platforms:

    • CC1200 Pi HAT ā€” the original supported hardware
    • SX1255 Pi HAT ā€” newly supported this month
    • MMDVM-compatible hotspots and modems ā€” for those who already have MMDVM hardware

    All three give you the full M17 feature set, including voice, SMS messaging, and GNSS-based station position mapping ā€” features that many other M17 hotspot platforms don’t support.

    Both the SX1255 and MMDVM platforms support full duplex operation, which means they can be used as full M17 repeaters ā€” not just hotspots. If you’ve been thinking about putting up an M17 repeater, this is a viable path.

    Getting started

    The easiest way to get a working hotspot is DK1MI’s installer script, which sets up m17-gateway along with a web dashboard. If you just want the gateway itself, pre-built .deb packages for arm64 are on the releases page, or you can build it yourself from the instructions in the README.

    Also in the project: an experimental messaging bridge

    There’s also a new and very experimental tool called m17-bridge that connects M17 SMS traffic to Discord, IRC, and APRS. It’s not ready for production use yet, but in the next month or two I plan to stand up a public example node so folks can experiment with it. Stay tuned!

    Latest release is v0.5.1. Full source, docs, and binaries at: https://github.com/jancona/m17

Image
Image