ECHOCAT — Remote Phone Control

ECHOCAT turns your phone or tablet into a wireless remote for your POTACAT-connected radio. Tune spots, transmit, stream audio, send CW, log QSOs, and even run POTA activations — all over a secure connection.

ECHOCAT comes in two flavors:

• ECHOCAT for iOS and Android — native apps, available on the App Store and Google Play for a one-time $9.99 purchase. The apps add features a browser can’t do: keep listening with the screen locked, QR-code pairing, automatic switching between connection paths, and Bluetooth accessories like BLE PTT buttons.
• ECHOCAT Web — free, built into POTACAT, and runs in any modern mobile browser. Nothing to install.

Both work at the same time — pairing the app doesn’t disable browser access.

Note: The app is a remote control for POTACAT Desktop — the desktop does the heavy lifting. When something misbehaves, update POTACAT Desktop first; most app-side problems are fixed there.

What You Need

• POTACAT running on your shack PC, connected to your radio
• A phone or tablet with the ECHOCAT app — or a modern browser (Safari on iOS, Chrome on Android) for ECHOCAT Web
• A connection path between the two: your home Wi-Fi, Tailscale, or the POTACAT Cloud tunnel (see Connection Paths)

Quick Start

1. Enable ECHOCAT on the Desktop

Open POTACAT and click the gear icon in the top bar to open Quick Settings. Toggle ECHOCAT on. You’ll see:

• A URL (e.g., https://192.168.1.50:7300)
• A 6-character token (e.g., A1B2C3)

If you have Tailscale installed, the Tailscale address is shown with a green label — use that green https:// URL for remote access (the hostname, not the 100.x.x.x IP).

You can also configure ECHOCAT from Settings > ECHOCAT, where you can change the port (default 7300), regenerate the token, set the PTT safety timeout, and select audio devices.

2. Pair the App (iOS/Android)

Pairing links the app to your desktop with a QR code — no typing IP addresses.

1. In POTACAT, open Settings > ECHOCAT and click Open pairing QR (requires desktop v1.9.2 or later)
2. In the ECHOCAT app, scan the QR code — or scan it with your phone’s camera app and open the link
3. A pairing-approval popup appears front and center on the desktop — click Approve

On the same network, the app can also discover your desktop automatically (“tap to pair”) — tap the discovered rig and approve the request on the desktop.

Tip: If the in-app scanner won’t cooperate, generate the pairing URL on the desktop and open it directly in your phone’s browser. For anything else that goes wrong, see the Connectivity & Pairing guide.

Once paired, the app shows which path it’s using — LAN, TAIL, or CLOUD — with the current latency in milliseconds at the top of the screen.

3. Or Open ECHOCAT Web in a Browser

No app? Use the free browser interface:

1. Open your phone’s browser and navigate to the URL shown in POTACAT
2. You’ll see a certificate warning (ECHOCAT uses a self-signed TLS certificate on the LAN) — tap Advanced > Proceed to accept it
3. If token authentication is enabled, enter the 6-character token and tap Connect

That’s it — you’re connected. You’ll see the spot list, a frequency display, and the mode badge at the top.

4. Select Audio Devices

In Settings > Radio (on the rig’s configuration), set the ECHOCAT Audio Input and ECHOCAT Audio Output devices. These control which sound devices carry RX audio from the radio to your phone and TX audio from your phone to the radio.

• Audio Input: The device that receives audio from your radio (e.g., a virtual audio cable output, or your radio’s USB audio device)
• Audio Output: The device that sends audio to your radio’s TX input

Tip: You can also change audio devices from the Quick Settings panel without opening the full Settings dialog.

Using ECHOCAT

Tuning

Tap any spot in the list to tune your radio to that frequency and mode. The status bar at the top shows the current frequency and mode.

To tune manually, tap the frequency display to open the dial pad. Enter a frequency in MHz (e.g., 14.060) and tap a step size to nudge the frequency up or down.

Transmitting (PTT)

Tap and hold the red PTT button at the bottom of the screen to transmit. Release to return to receive. A safety timer (default 3 minutes) automatically drops PTT if you forget to release it.

The STOP button is an emergency kill switch that immediately drops PTT and halts any CW or digital transmission.

Audio

Tap the Audio button to start streaming. Your phone will ask for microphone permission — this is needed for TX audio.

• RX audio streams from your radio to your phone speaker/earpiece
• TX audio streams from your phone microphone to the radio when PTT is held
• Tap Vol to cycle through gain levels (1x, 2x, 3x) if RX audio is too quiet

iOS note: In ECHOCAT Web, keep the browser in the foreground or use the Audio button to maintain the connection — iOS aggressively suspends background WebSocket connections. The native app doesn’t have this problem: it keeps streaming with the screen locked.

Scanning

Tap the Scan button in the status bar to auto-tune through your filtered spot list. The radio dwells on each spot for a configurable time (default 7 seconds, adjustable in the settings overlay). Tap Scan again or tap any spot to stop.

Filters

Tap the gear icon on the phone to open the settings overlay where you can filter by:

• Bands (160m through 6m)
• Modes (SSB, CW, FT8, FM, etc.)
• Regions (NA, EU, AS, etc.)
• Spot sources (POTA, SOTA, WWFF, LLOTA, DX Cluster)
• Max age — hide spots older than a set time
• New parks only — show only parks you haven’t worked
• Hide worked — hide callsigns you’ve already logged

Radio Controls

Tap the rig controls button to reveal additional controls:

• Filter width — step the IF bandwidth narrower or wider
• NB — toggle the noise blanker
• ATU — toggle the antenna tuner (if your radio supports CAT-controlled ATU)
• VFO A/B — switch VFOs or swap A⇄B
• RF Gain slider (0–100%)
• TX Power slider (0–100%)

In the native app, these rig controls (including custom CAT commands) live behind the CAT button at the top of the screen — easy to miss if you’re looking for a settings menu.

Remote Rig Power On/Off

If your radio supports power control over CAT, you can power it on and off from your phone. In the app, the power controls are in the VFO tab.

Tip: On Icom rigs, if power-off works but power-on doesn’t, set the radio’s CI-V Baud Rate to AUTO — CAT power-on requires a wake-up preamble that’s sensitive to the baud setting.

To go fully remote, the POTACAT Launcher — a small companion daemon on port 7301 — lets the app start or restart POTACAT Desktop itself. It runs in the system tray and requires the installed POTACAT (not a source build).

Rotor Control

If you have PSTRotator configured in POTACAT, a rotor toggle appears in the radio controls section. When enabled, tuning a spot automatically sends the bearing to your rotator.

CW from Your Phone

ECHOCAT includes a full CW keyer that lets you send CW from your phone’s touchscreen or a Bluetooth MIDI paddle.

Enable CW

1. In POTACAT desktop Settings > ECHOCAT, check Enable CW Keyer
2. On your phone, the CW panel appears when you’re in CW mode

CW Panel Controls

• WPM — adjust sending speed (5–50 WPM)
• Keyer mode — Iambic B, Iambic A, or Straight Key
• Sidetone — adjustable frequency (400–900 Hz) and volume
• 5 macro buttons — programmable CW messages (default: CQ, 599, 73, AGN, TU). Customize the labels and text in POTACAT’s desktop settings.
• Free text field — type any text and send it as CW

CW Keying Methods

ECHOCAT supports three keying methods that can work simultaneously:

1. Text macros (KY command) — Tap a macro button and the radio’s internal keyer sends the text. Best for programmed messages with clean keying. Requires radio firmware support (QMX firmware 1_00_021+).

2. Paddle CW (TX/RX keying) — Touch the on-screen paddle or use a Bluetooth MIDI paddle. Your phone sends paddle contact events over WebSocket, POTACAT’s iambic keyer generates the timing, and TX/RX commands key the radio. Preserves your sending rhythm.

3. Hardware DTR keying — A dedicated USB-to-serial adapter wired to your radio’s key jack. Best for absolute timing precision. See the Remote CW Setup Guide for wiring details.

Sidetone: For paddle CW and DTR keying, your phone generates local sidetone via its speaker — the radio’s sidetone is not used since TX/RX keying bypasses the radio’s internal keyer.

FT8 / Digital Modes (JTCAT)

ECHOCAT integrates with POTACAT’s JTCAT feature for remote FT8/FT4 operation.

Tap the FT8 tab on your phone to access:

• Band selection (80m–6m) with one-tap band changes
• Mode selector (FT8, FT4, FT2)
• Decode log — live scrolling list of decoded stations
• TX controls — enable TX, call CQ, reply to stations
• Waterfall — live spectrum display streamed from the desktop
• Auto QSO sequencing — JTCAT handles the exchange sequence; you just pick who to call

Activator Mode

ECHOCAT supports running full POTA/SOTA activations from your phone.

Start an Activation

1. Tap the Activate tab
2. Select your activation type (POTA, SOTA, or Other)
3. Enter your park/summit reference (autocomplete helps you find it)
4. Tap Start Activation

Logging QSOs

During an activation, tap the Log button next to any spot, or use the quick-log form:

• Enter callsign, RST sent/received, and optional notes
• QSOs are numbered and timestamped automatically
• Your contact list shows at the bottom of the activation view

Re-spotting

When you log a QSO during an activation, ECHOCAT can automatically re-spot you on POTA/SOTA/WWFF. Configure your re-spot comment template in POTACAT’s desktop settings (e.g., {rst} in {QTH} 73 {mycallsign} via POTACAT).

Export

Tap Export ADIF to generate an ADIF file of your activation contacts. Past activations are saved and viewable with individual map views showing your QSO locations.

Club Station Mode

For multi-operator club stations, ECHOCAT supports authenticated access with license privilege enforcement.

Setup

1. In POTACAT Settings > ECHOCAT, enable Club Station Mode
2. Point it to a club_users.csv file with columns for callsign, password, license class, and rig access
3. Each member logs in with their callsign and password

How It Works

• Members can only tune frequencies within their license class privileges (e.g., a US Technician can’t tune 80m SSB)
• Rig access can be restricted per member
• The OPERATOR field in logged QSOs is set to the individual member’s callsign
• All actions (logins, tunes, PTT, rig switches) are written to an audit log

Connection Paths

There are three ways for your phone to reach POTACAT. The app checks all of them at connect time and uses the fastest — walk into the house mid-QSO and it hands off from Cloud or Tailscale to LAN automatically. The indicator at the top of the app shows the active path (LAN, TAIL, or CLOUD) and the latency.

Tip: Stuck at any point? The ECHOCAT Connectivity & Pairing guide walks through each path in plain English, including the two Tailscale settings that cause most failures.

Same Network (LAN)

On your home Wi-Fi, your phone reaches POTACAT directly at its LAN IP address. No special setup needed beyond enabling ECHOCAT.

Tailscale

Tailscale is a free VPN that connects your phone and shack PC wherever they are — and it will keep working as a supported path indefinitely:

1. Install Tailscale (free) on both your shack PC and your phone, signed in to the same account
2. In the Tailscale admin console at login.tailscale.com/admin/dns, enable MagicDNS and HTTPS Certificates — pairing fails without both
3. Connect using the MagicDNS hostname shown in POTACAT’s ECHOCAT panel (highlighted in green) with https:// — the Tailscale 100.x.x.x IP will not work, because the TLS certificate is issued only for the hostname
4. No port forwarding or firewall changes needed

See the Connectivity & Pairing guide for the full walkthrough, including the device-key expiry gotcha that makes Tailscale setups stop working after a couple of months.

POTACAT Cloud Tunnel

The Cloud tunnel is the simplest remote path: your desktop opens an outbound-only tunnel to POTACAT Cloud and gets a personal address like yourcallsign.potacat.com. Because the connection is outbound from the shack, there is nothing to forward, no VPN to install, and no inbound firewall hole — it even works behind CGNAT (Starlink and many cellular ISPs), where port forwarding is impossible.

Security is layered: the tunnel accepts no inbound connections, pairing tokens are one-time-use, and requests are rate limited.

Share Your Rig

With POTACAT Cloud you can grant another operator timed access to your radio — a friend without HF at home, a club member, or a licensed guest anywhere in the world.

• You issue a guest pass: a four-word code (like prague-plankton-potato-idaho) that expires after a set number of hours
• You can cap TX power, and band privileges are enforced based on the guest’s license class
• The guest needs a free POTACAT Cloud account — this provides the audit trail of who operated your station
• Rig sharing requires the Cloud tunnel; Tailscale covers your own devices, but sharing means Cloud (or adding the guest to your Tailnet yourself)

Note: The remote guest is the control operator and operates under their own callsign, per the usual remote-operation rules. Check the regulations that apply in your country.

Security

Certificate Warning (ECHOCAT Web)

On the LAN, ECHOCAT uses a self-signed TLS certificate. Your browser will warn you the first time — accept the certificate and it will be remembered for future sessions. Over Tailscale, ECHOCAT uses a real certificate issued for your MagicDNS hostname, so there’s no warning — but that’s also why you must connect by hostname, not IP.

Token Authentication

The 6-character hex token adds an extra layer of access control for browser connections. It’s optional — enable it if other people can reach your network. You can regenerate it at any time from the desktop settings.

Settings Reference

Troubleshooting

Note: For pairing failures, Tailscale problems, “it worked for weeks and then stopped,” and audio issues, see the dedicated ECHOCAT Connectivity & Pairing guide.

Can’t reach the ECHOCAT URL:

• Make sure ECHOCAT is enabled (green indicator in POTACAT’s connection bar)
• Verify your phone is on the same network as the PC (or both are on Tailscale, with MagicDNS and HTTPS Certificates enabled)
• Check that the port (default 7300) isn’t blocked by your firewall
• If the URL shows a 169.254.x.x address, Tailscale isn’t actually running on the PC

Certificate error won’t go away:

• On iOS Safari, you may need to tap “Show Details” then “visit this website”
• On Android Chrome, tap “Advanced” then “Proceed to [IP] (unsafe)”

No audio:

• Tap the Audio button on the phone and allow microphone access
• Check that the correct audio devices are selected in Settings > Radio
• On iOS, make sure your phone isn’t on silent mode

PTT not working:

• Verify your radio’s CAT connection is active (green dot in status bar)
• Check the PTT safety timeout hasn’t expired (the phone will show a warning)
• Tap the STOP button and try again

High latency / audio dropouts:

• Use a 5 GHz Wi-Fi network instead of 2.4 GHz
• If using Tailscale remotely, latency depends on your internet upload speed at the shack
• Close other bandwidth-heavy applications

Phone disconnects when screen locks:

• On iOS, keep the browser in the foreground while operating
• The audio session helps keep the connection alive, so start audio before locking the screen
• On Android, disable battery optimization for your browser
• The native iOS/Android app keeps streaming with the screen locked — worth the upgrade if you operate this way often