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Quick Start

Get your QMX Panadapter on air in 10 minutes.

Prerequisites

  • M5Stack Tab5 (ESP32-P4, 5" display)
  • QRP Labs QMX or QMX+ transceiver
  • USB-C power cable (5 V / 2 A minimum)
  • USB-A to USB-C data cable (connects Tab5 to QMX)
  • WiFi network (optional, for remote control and logging)

Step 1: Verify QMX Firmware

Power the QMX on standalone and check the firmware version displayed on its screen. You need v1.03.002 or newer. If yours is older, update the QMX first — everything that follows depends on recent firmware. Both v1.03.002 and the v1.04 betas work with the panadapter; on v1.04 you additionally get AM mode and an Antenna Tune button (SWR tune with a live power/SWR readout). Both stay hidden on v1.03.002, so either firmware is fine.

Step 2: Flash the Tab5

Download the latest flasher from the Releases page:

  1. Plug Tab5 into your computer with a USB-C data cable
  2. Double-click flash.bat
  3. Press Enter for a normal flash (keeps your settings) or type E for a clean flash (wipes everything)
  4. Wait for SUCCESS
  1. Plug Tab5 into your computer with a USB-C data cable
  2. Open Terminal and run: bash flash.command
  3. If you haven't installed esptool: brew install esptool
  4. Press Enter for normal flash
  5. Wait for SUCCESS
  1. Plug Tab5 into your computer with a USB-C data cable
  2. Run: bash flash.command
  3. If you haven't installed esptool: pip3 install esptool
  4. Press Enter for normal flash
  5. Wait for SUCCESS

The firmware is already inside the zip — the three .bin files next to the script are what get flashed. The only thing fetched from the internet is esptool, once, if your computer doesn't already have it, so after the first successful run the flasher works offline.

Step 3: Connect the Cables

You need two USB connections:

Connection Tab5 Port Cable Carries
Tab5 ← QMX USB-A (host) USB-A to USB-C, data cable I/Q audio + CAT control
Tab5 ← Power USB-C Any USB-C power cable 5V power

⚠️ Cable gotcha: Many USB-C cables are charge-only. If the spectrum stays flat and the top bar shows Band: ---, you have a charge-only cable. Swap it for one you know does data (USB stick, phone sync, etc.).

Step 4: Power On

  1. Tab5 first — turn it on. The screen fades up gently from black as it loads.
  2. QMX second — turn on the QMX. Until the radio is connected, the Tab5 shows a full-screen "turn on / reboot your QMX" prompt — that's normal, not a fault, and it clears automatically once the QMX is talking.
  3. Within a few seconds the top bar should show Band / Mode / BW, and the spectrum should come alive

Step 5: Fill in Your Settings

On first boot you'll be prompted for:

  • Callsign — your amateur radio callsign
  • Grid — your Maidenhead grid square (e.g., JO45)
  • WiFi — SSID and password (optional, skip if you're portable)

You can change these anytime by swiping right from the screen edge to open the settings drawer.

Step 5b: Optional — microSD Card (station backup)

Insert a microSD card (a plain FAT32 32 GB card is ideal) into the Tab5's slot before switching it on, and it automatically mirrors your whole station to /qmx-panadapter/ on the card — a grab-and-go backup you can pull into a PC or another Tab5, no computer needed in the field:

  • ADIF QSO log — mirrored after each new QSO
  • Config export — all settings + memory channels (restore via the web Config upload)
  • LoTW certificate + key — so a restored device can sign QSOs for LoTW
  • Diagnostic log — rolling copy
  • README.txt — describes every file on the card

The SD dot in the bottom status bar shows what is happening (absent = no card, which is not an error):

  • Green — mirroring continuously. This is the case with WiFi off, i.e. normal POTA/SOTA operating.
  • Yellow — your start-up backup is written and mirroring has stopped. This is the case with WiFi on: the card and the WiFi co-processor share a bus and can't both use it reliably, so the Tab5 takes the full backup within a few seconds of switching on and then leaves the card alone. QSOs made later in that session are written at the next start-up.

Insert the card before switching on. A card pushed in later isn't picked up until you restart.

⚠️ The backup contains credentials (WiFi password, QRZ/eQSL logins, LoTW private key) — keep the card physically secure. Skipping this step is fine; your logs and settings always live in the device's own storage too.

Step 6: Navigate the Screen

The entire app runs on edge swipes and taps on the top bar:

Action Does
Swipe → from left edge Toggle Panadapter ↔ FT8/FT4 view
Swipe ← from right edge Open settings drawer
Swipe ↑ from bottom edge Open memory channel picker
Tap any top bar item Open that item's selector (Freq, Mode, BW, etc.)

You'll see faint "breathing" grip handles on the edges — they show you where to swipe.

Step 7: Start Listening

You're now receiving. The spectrum shows signal strength across the band, and the waterfall scrolls down showing signal activity over time.

  • Tap the spectrum or waterfall to tune to that frequency
  • Pinch to zoom in/out; one-finger horizontal drag to pan and retune
  • Tap the coloured band-plan strip (along the bottom, just above the status bar) to jump to a frequency, or drag along it to scrub through the band — you can also grab it from anywhere on the bottom bar and drag sideways (a vertical up-swipe there still opens memory channels)
  • Tap the Freq label on the top bar to open the frequency keypad — drag the "Enter freq" title bar to reposition it, pinch or swipe up/down to resize it
  • Swipe ↑ from the bottom edge to open memory channels — tap an empty slot to create one, long-press a filled slot to edit it, long-press and drag to move a channel (or drag it onto the wastebin cell to delete it). A new device comes with a few example channels and plays a one-time tour of these gestures the first time you open the picker
  • Tap Band to switch between your configured bands
  • Tap Mode to switch USB/LSB/CW/DiGi

Step 8: FT8 Mode (Optional)

Swipe → from the left edge to switch to FT8 view. You'll see:

  • Live decode list — all FT8 stations heard on frequency
  • Waterfall — same real-time spectrum waterfall
  • Call CQ button — transmit a CQ (requires QMX to be on the air)
  • Reply rows — tap a station to reply to their CQ

Step 9: WiFi & Web UI (Optional)

If you set up WiFi:

  1. Open your browser to http://qmx.local (or the IP shown in the Tab5's bottom bar, if your network blocks .local names)
  2. You'll see a remote spectrum, waterfall, and control panel — plus QSO log downloads and uploads to QRZ, eQSL, and LoTW
  3. No installation or configuration needed — just open and go

Step 10: Keeping It Up To Date

From v1.8.9 the Tab5 can update itself over WiFi. You do not need the cable again unless something goes badly wrong. From v1.9.3 it also fetches the update quietly in the background, so by the time it says anything, the work is already done and only one decision is left.

When a newer release has been downloaded and is waiting for you, the version at the bottom of the screen changes to show it, in light green, and breathes gently so you notice it:

v1.9.2 -> v1.9.3 ?

Tap the bar — anywhere along it — and a window opens in the middle of the screen with the version, what will happen, and two buttons:

  • Restart now — the screen goes dark and the Tab5 comes back on the new firmware, about 20 seconds.
  • Later — the window closes and the bar stops breathing. The line stays, quietly, and tapping it opens the window again whenever you are ready.

Nothing restarts on its own. You choose when, so it can never interrupt a contact.

While a download is running the line is amber and counts up, and the spectrum, waterfall and FT8 decoding all keep working — expect a slight stutter and one brief pause right at the end while the new firmware is verified:

v1.9.2 -> v1.9.3  42%

The same window is available from the web page, in the same words.

If you would rather it did not download by itself

The background download is on by default and can be switched off in Settings → Network → Download updates automatically. Turn it off if you are on a metered connection — a phone hotspot in a field, for instance — since each update is about 3.3 MB. With it off, the bar offers the update and the window's button reads Download now instead.

Downloading never applies anything on its own. Only the restart does that, and only you can ask for it.

Checking straight away

The Tab5 looks for a new release every 30 minutes, so an announcement can take that long to show up. If you have just read that a release is out and want to see it now, tap the version even while it says you are up to date. The window offers Check now. Tapping the version in the web page does the same.

That is also the quickest way to satisfy yourself the whole mechanism works before you ever need it.

Your settings, QSO log, LoTW certificate and memories are untouched by an update. The previous firmware is also kept, so a failed update falls back to it by itself.

⚠ Restarting the Tab5 with the QMX connected usually means switching the radio off and on again afterwards — the screen will tell you if so.

Troubleshooting

Spectrum is flat? - Check the USB cable between Tab5 and QMX — charge-only cables won't work - Verify QMX is powered on and not in standby - Restart both devices (Tab5 first, then QMX)

QMX doesn't appear? - Check QMX firmware version (Step 1 above) — should be v1.03.002 or newer (the v1.04 betas also work) - Try a different USB cable

Flashing keeps failing, but the COM port is there? - Reboot the Tab5 and try again — do this first. The Tab5's USB serial connection is produced by the ESP32-P4 itself rather than by a separate chip, so a busy running firmware can leave the port listed in Windows Device Manager while it no longer answers the flasher. A reboot clears it. - Then the usual suspects: a charge-only USB-C cable, or a serial monitor still holding the port.

WiFi won't connect? - Check your SSID and password spelling - Restart the Tab5 and try again - See Troubleshooting for more

Still stuck? - Ask the Tab5 first. Open the settings drawer (swipe in from the right edge) and tap Need guidance? — pick the symptom in plain words and it opens the manual at the answer. Anything the device can see for itself is highlighted at the top of that list. See Getting Help - The diagnostic log is always on — nothing to enable. Download it via the web UI: open the Files menu in the web page's bottom bar and click Diagnostic download ↓ (downloads both the live log and the saved pre-reboot copy), or pull qmx-log.txt from an inserted microSD card - Report the issue on GitHub Issues or the QRPLabs Groups.io thread and attach the log

Next steps: Read the full User Guide or dive into FT8 Transmit.