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Remote CW Keying

ECHOCAT lets you send real CW — your own fist, on your own paddle — through the radio in your shack from anywhere your phone can reach it. This page covers the remote keying chain; for the desktop keyer itself (keyer modes, WinKeyer, CW Key Port, macros), see the CW Keyer page.

How It Works

paddle/adapter → phone browser (keyboard or MIDI events) → WebSocket → desktop POTACAT → IambicKeyer → radio

Your paddle adapter sends keyboard or MIDI events to the ECHOCAT page on your phone. ECHOCAT forwards dit/dah events over the WebSocket to desktop POTACAT, whose IambicKeyer state machine generates the element timing and keys the radio — via a CAT command or a DTR pin, depending on your rig. The sidetone is generated locally on the phone, so it fires the instant you press the paddle.

You don’t need a paddle at all to work CW remotely: the CW text box and the five macro buttons send CW via CAT on supported rigs.

Enabling It

  1. On the desktop, open Settings > ECHOCAT and check Enable Remote CW Keyer. This is the one that matters for phone keying — you do not need the desktop Enable CW Keyer checkbox (that’s for local keying on the PC).
  2. Leave CW Key Port set to (none) unless you have an external USB-serial adapter plugged into your radio’s key jack (see when you need one). On rigs like the IC-7300, POTACAT keys the radio directly through the CI-V connection with no extra hardware.
  3. On your phone, the CW panel appears at the bottom when you’re tuned to a CW frequency. If it says CW unavailable, the Remote CW Keyer setting isn’t enabled on the desktop.

Tip: The first key event writes [CW] Keying route: ... to the verbose CAT log. If you see no [CW] lines at all, your paddle events aren’t reaching the desktop — check the phone-to-desktop connection before suspecting the radio.

Supported Key Hardware

HardwareSendsNotes
N6ARA TinyMIDIKeyboard mode: [ (dit) and ] (dah); MIDI mode also worksKeyboard mode is the reliable path on iPhone
Vail adapterLeft Ctrl (dit) / Right Ctrl (dah)Keyboard emulator
VBand dongleLeft Ctrl (dit) / Right Ctrl (dah)Same scheme as Vail
K1EL WinKeyerConnects to the desktop, not the phoneConfigure under Settings > CW Keyer on the PC
Anything that types characters (e.g. Morserino as a Bluetooth keyboard)TextFills the CW text box — not paddle keying

Keyboard mode vs. MIDI mode

  • iOS Safari does not support Web MIDI — use keyboard mode on iPhone/iPad.
  • Android MIDI needs a Chromium-based browser plus a BLE-MIDI bridge app from the Play Store to link the adapter.
  • Keyboard mode has one downside: the adapter becomes a keyboard, so your phone’s pop-up keyboard disappears while it’s connected.
  • The native ECHOCAT iOS/Android apps support MIDI natively — no browser workarounds needed.

On-Screen Straight Key

No hardware handy? The ECHOCAT app has an on-screen straight key: enable it under Settings > C.W. Keyer in ECHOCAT, and a Key button appears in place of PTT on CW frequencies. Hold it down to key — it’s your fist, rough edges and all, rather than a stored message.

Latency Expectations

  • Sidetone is instant. It’s generated on the phone, so there’s no perceptible delay between paddle press and sidetone, regardless of network conditions.
  • The RF side follows your network. Local sidetone doesn’t change when the radio actually keys — the transmitted elements are timed by the desktop keyer, but they start after the round trip to your shack.
  • Use wired headphones — Bluetooth adds noticeable audio lag.
  • Mobile browsers take a moment to warm up audio at the start of a session; a one-time “click” when audio unlocks is the phone’s audio hardware waking up and is normal.
  • Any VPN that lets your phone reach the shack PC works — Tailscale is popular but not required.

Rig Recipes

QRP Labs QMX

Note: QMX firmware 1.03 or later is required for DTR keying on the second USB port.

A known-good setup:

  1. POTACAT rig: Serial CAT (Kenwood) on the QMX’s first USB port at 38400 baud, with Disable DTR/RTS on connect checked
  2. Audio in/out: the QMX Digital Audio Interface
  3. QMX menus: System/GPS & Ser. Ports > Serial Ports = 2, and CW/CW Keyer > Key from USB DTR = USB 2
  4. CW Key Port (DTR Keying): the QMX’s second COM port

Icom IC-7300 / IC-705 / IC-7610

Set the rig menu MENU > SET > Connectors > USB Keying (CW) = USB(A) DTR (preferred), or USB SEND = DTR. POTACAT prints this menu path in the log when it routes keying via the main port’s DTR line.

Warning: Remote CW on Icom requires a direct CI-V serial connection, not rigctld/hamlib. On direct CI-V, POTACAT sends a CI-V “CW key down/up” command for each paddle element. Hamlib has no such command — it only exposes the mic PTT line — so paddle keying over rigctld puts the transmitter on with the CW key line untouched: a silent key-down.

Yaesu

Most Yaesu CAT ports only accept text CW (the KY command), not real-time paddle keying. To key a paddle on a Yaesu, set CW Key Port to a USB-serial adapter wired to the radio’s key jack. Exceptions and specifics:

  • FTDX101D: real-time keying works over CAT (TX1;/TX0;) — no DTR adapter needed.
  • FT-710: even text CW over KY is unreliable on this rig. Set CW Key Port to the radio’s CAT-2 serial port (the second COM port, e.g. COM<n+1>), and on the radio set OPERATION SETTING > CAT/LINEAR/TUNER > USB Keying (CW) = DTR. Also set CAT-1 TIME OUT TIMER = 1000 ms and turn CW BK-IN on.

Known Limitations

  • Yaesu FT-891 / FT-991A: text CW keys the transmitter but produces zero RF. The 991A’s KY command has no free-text form — the text is silently ignored while the TX light comes on — and the FT-891 shows the same symptom. This is a known open limitation of text/macro CW on these rigs.
  • Break-in must be on. If the radio keys and you hear sidetone but no RF goes out, check that break-in (BK-IN) is enabled — and note the FTDX10 remembers the break-in setting per band.
  • Linux DTR limitation. The cdc_acm kernel driver used by USB-CDC rigs (QMX, QDX, IC-7300 family) can’t control the DTR pin, so paddle keying fails with Operation not supported. The fix is a ~$5 FTDI or CH340 USB-serial adapter wired to the rig’s key jack, set as the CW Key Port — its driver handles DTR correctly. CW text macros still work over the main CAT port. Windows and macOS are unaffected. See the CW Keyer page for details.
  • Some users on Samsung Android phones report truncated sidetone and the radio not keying with TinyMIDI/VBand adapters in the browser; the native mobile apps are the recommended path there.

Stopping a Transmission

Tap the HALT/STOP button next to PTT in ECHOCAT (or press ESC in the desktop CW Macros window) to stop a macro mid-send.