DX Cluster

The DX Cluster panel provides a live feed of DX spots via a WebSocket connection to the G7VRD DX cluster.

Opening the DX Cluster

  • Press Shift+D (when not typing in an input field)
  • Or click the DX Cluster button in the Settings dropdown

The panel opens as a modal overlay — extra large on desktop, fullscreen on mobile.

Connection

The app connects to ws.g7vrd.co.uk/dx using STOMP over SockJS and subscribes to the spot feed. Connection happens automatically when you open the panel.

Connection Status

Status text appears in the modal header:

Status Meaning
Not connected Initial state before opening
Connecting... WebSocket handshake in progress
Connected - waiting for spots... Link established, no spots yet
Connected Receiving spots
Connection lost - reconnecting... Unexpected disconnect
Reconnecting (X/5) in Ys... Auto-retry with backoff
Disconnected User-initiated disconnect

Auto-Reconnect

If the connection drops unexpectedly, the app retries automatically with exponential backoff:

  • Up to 5 attempts
  • Delays: 2s, 4s, 8s, 16s, 32s (capped at 60s)
  • After 5 failures, reconnection stops and a toast suggests clicking Connect manually

Spot Display

Each spot row shows six columns:

Column Example Description
Time 14:23:45z UTC timestamp
Callsign JA1ABC The DX station being spotted
Frequency 14.256 MHz (20m) Operating frequency with band
Mode CW Transmission mode (or "-" if unknown)
Spotter W1AW Who reported the spot
Comment CQ NA Truncated with tooltip on hover

Spots are displayed newest-first. The table header is sticky so it stays visible while scrolling.

Rolling Buffer

The app keeps a rolling buffer of spots in memory. When the buffer is full, the oldest spots are dropped as new ones arrive.

Setting Default Options
Max spots 100 50, 100, 200, 500

The count badge in the header shows the current spot count (e.g., "25/100" when filters are active).

Filtering

Two filter dropdowns appear above the spot table:

Filter Description
Band Show only spots on a specific band (e.g., 20m). Options populated dynamically from received spots.
Mode Show only a specific mode (e.g., CW, SSB). Options populated dynamically from received spots.

Both filters work together (AND logic). When active, the count badge shows filtered/total. The spot buffer retains all spots regardless of filters — changing filters instantly shows/hides without re-fetching.

Clicking a Spot

Click any row in the spot table to:

  1. Fill the callsign field with the spotted DX call
  2. Fill the frequency field (converted from kHz to MHz)
  3. Close the DX Cluster modal
  4. Focus the callsign field
  5. Trigger an automatic QRZ lookup

You're ready to call.

Background Operation

By default, the WebSocket connection closes when you close the DX Cluster panel. Enable Run in Background in the DX Cluster settings to keep receiving spots even when the panel is closed.

Background Mode Behavior
Off (default) Connection drops when panel closes. Reconnects when reopened.
On Connection stays alive. Spots accumulate in memory. Reopen the panel anytime to see them. Also auto-connects on page load.

The status text shows "(Background)" when background mode is active.

Configuration

Click the gear icon in the DX Cluster header to open settings:

Setting Default Description
Run in Background Off Keep the WebSocket alive when the panel is closed
Maximum Spots 100 How many spots to retain (50, 100, 200, or 500)

Reducing the max spots setting immediately trims any excess. Settings are saved to localStorage.

Clearing Spots

Click the trash icon in the header to clear all spots from memory. This doesn't affect the connection — new spots will continue arriving.

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