feat(filters): add ft2 mode to filtering options

server/routes/dxcluster.js

@@ -1044,7 +1044,7 @@ module.exports = function (app, ctx) {
     const other = [];
     for (const p of paths) {
       const c = String(p.comment || '').toUpperCase();
-      if (/\bFT[84]\b/.test(c)) ft8ft4.push(p);
+      if (/\bFT[842]\b/.test(c)) ft8ft4.push(p);
       else if (/\b(CW|RTTY|PSK)/.test(c)) other.push(p);
       else voice.push(p); // voice keywords or no mode marker — human spots
     }

server/utils/propagationPhysics.js

@@ -59,6 +59,10 @@ const MODE_ADVANTAGE_DB = {
   PSK31: 10,
   FT8: 34,
   FT4: 30,
+  // FT2 trades sensitivity for speed: decode threshold is -12/-13 dB vs
+  // FT4's -17.5 and FT8's -21 (ft2.it technical document) — the LEAST
+  // sensitive of the FTx modes despite being the fastest.
+  FT2: 25,
   WSPR: 41,
   JS8: 37,
   OLIVIA: 20,

src/components/ActivateFilterManager.jsx

@@ -22,6 +22,7 @@ const MODES = [
   'FST4',
   'FST4W',
   'FST4W-90',
+  'FT2',
   'FT4',
   'FT8',
   'HELL',

src/components/DXFilterManager.jsx

@@ -45,7 +45,7 @@ export const DXFilterManager = ({ filters, onFilterChange, isOpen, onClose, onCl
     '2m',
     '70cm',
   ];
-  const modes = ['CW', 'SSB', 'FT8', 'FT4', 'RTTY', 'PSK', 'JT65', 'JS8', 'SSTV', 'AM', 'FM'];
+  const modes = ['CW', 'SSB', 'FT8', 'FT4', 'FT2', 'RTTY', 'PSK', 'JT65', 'JS8', 'SSTV', 'AM', 'FM'];
 
   // noinspection DuplicatedCode
   const toggleArrayItem = (key, item) => {

src/components/PSKFilterManager.jsx

@@ -22,6 +22,7 @@ const MODES = [
   'FST4',
   'FST4W',
   'FST4W-90',
+  'FT2',
   'FT4',
   'FT8',
   'HELL',

src/hooks/useBandHealth.js

@@ -62,6 +62,17 @@ const ISLANDS = [
   { mhz: 21.074, mode: 'FT8' },
   { mhz: 24.915, mode: 'FT8' },
   { mhz: 28.074, mode: 'FT8' },
+  // FT2
+  { mhz: 1.843, mode: 'FT2' },
+  { mhz: 3.578, mode: 'FT2' },
+  { mhz: 5.36, mode: 'FT2' },
+  { mhz: 7.052, mode: 'FT2' },
+  { mhz: 10.144, mode: 'FT2' },
+  { mhz: 14.084, mode: 'FT2' },
+  { mhz: 18.108, mode: 'FT2' },
+  { mhz: 21.144, mode: 'FT2' },
+  { mhz: 24.923, mode: 'FT2' },
+  { mhz: 28.184, mode: 'FT2' },
   // FT4
   { mhz: 3.575, mode: 'FT4' },
   { mhz: 7.0475, mode: 'FT4' },

src/plugins/layers/useVOACAPHeatmap.js

@@ -213,7 +213,7 @@ export function useLayer({ map, enabled, opacity, locator }) {
           .map((g) => `<option value="${g}" ${g === gridSize ? 'selected' : ''}>${g}°</option>`)
           .join('');
 
-        const modeOptions = ['SSB', 'CW', 'FT8', 'FT4', 'RTTY', 'AM', 'FM']
+        const modeOptions = ['SSB', 'CW', 'FT8', 'FT4', 'FT2', 'RTTY', 'AM', 'FM']
           .map((m) => `<option value="${m}" ${m === propMode ? 'selected' : ''}>${m}</option>`)
           .join('');
 

src/utils/bandPlan.js

@@ -74,7 +74,7 @@ export const mapModeToRig = (mode, freq) => {
   if (m === 'DATA-USB' || m === 'DATA-LSB') return m;
 
   // Digital/data modes → DATA-USB or DATA-LSB based on band convention
-  const digitalModes = ['DATA', 'FT8', 'FT4', 'JS8', 'WSPR', 'JT65', 'JT9', 'PSK31', 'PSK63', 'RTTY', 'PKT'];
+  const digitalModes = ['DATA', 'FT8', 'FT4', 'FT2', 'JS8', 'WSPR', 'JT65', 'JT9', 'PSK31', 'PSK63', 'RTTY', 'PKT'];
   if (digitalModes.includes(m)) {
     return sb === 'USB' ? 'DATA-USB' : 'DATA-LSB';
   }

src/utils/callsign.js

@@ -43,7 +43,7 @@ export const CONTINENTS = [
 /**
  * Digital/Voice Modes
  */
-export const MODES = ['CW', 'SSB', 'FT8', 'FT4', 'RTTY', 'PSK', 'AM', 'FM'];
+export const MODES = ['CW', 'SSB', 'FT8', 'FT4', 'FT2', 'RTTY', 'PSK', 'AM', 'FM'];
 
 /**
  * Get band from frequency (in kHz)
@@ -93,6 +93,7 @@ export const detectMode = (comment, freq) => {
     const upper = comment.toUpperCase();
     if (upper.includes('FT8')) return 'FT8';
     if (upper.includes('FT4')) return 'FT4';
+    if (upper.includes('FT2')) return 'FT2';
     if (upper.includes('CW')) return 'CW';
     if (upper.includes('SSB') || upper.includes('LSB') || upper.includes('USB')) return 'SSB';
     if (upper.includes('RTTY')) return 'RTTY';
@@ -109,11 +110,14 @@ export const detectMode = (comment, freq) => {
   // Normalize to MHz (spots may arrive in kHz or MHz)
   const mhz = f > 1000 ? f / 1000 : f;
 
-  // Digital islands — narrow ±5 kHz windows around known calling frequencies
-  // DX cluster spots may report slightly off-frequency depending on the spotter's
-  // rig readout or the audio offset of the specific signal they clicked on.
-  // 3 kHz was too tight — 24.911 for 12m FT8 (dial 24.915) was being missed.
-  const TOLERANCE = 0.005;
+  // Digital islands — asymmetric windows around known calling (dial) frequencies.
+  // FTx signals occupy dial + 0–3 kHz (audio passband sits ABOVE the dial), so
+  // legitimate spots land in [dial, dial + ~3.1 kHz]; the small negative
+  // allowance covers rounded-down spot frequencies. A symmetric window cannot
+  // work here: FT2 dials sit only 4 kHz above FT4's, so ±5 kHz would swallow
+  // the neighbouring island. (An old note here defended ±5 kHz because a
+  // "24.911 FT8" spot was being missed — that was a busted spot; real FTx
+  // signals are never below the dial.)
   const DIGITAL_ISLANDS = [
     // FT8 calling frequencies
     { mhz: 1.84, mode: 'FT8' },
@@ -126,6 +130,23 @@ export const detectMode = (comment, freq) => {
     { mhz: 24.915, mode: 'FT8' },
     { mhz: 28.074, mode: 'FT8' },
     { mhz: 50.313, mode: 'FT8' },
+    // FT2 calling frequencies (tentative community QRGs — experimental mode,
+    // Decodium / WSJT-X Improved, not official WSJT-X)
+    // 160m: 1.843 sits exactly at the top of FT8 1.840's passband. FT8 is
+    // checked first, so a bare spot at exactly 1.8430 classifies as FT8 —
+    // inherent to the frequency plan. Real FT2 auto-spots carry "FT2" in the
+    // comment (matched before the islands) and audio offsets that push them
+    // past 1.8431, so only comment-less dial quotes hit the ambiguity.
+    { mhz: 1.843, mode: 'FT2' },
+    { mhz: 3.578, mode: 'FT2' },
+    { mhz: 5.36, mode: 'FT2' },
+    { mhz: 7.052, mode: 'FT2' },
+    { mhz: 10.144, mode: 'FT2' },
+    { mhz: 14.084, mode: 'FT2' },
+    { mhz: 18.108, mode: 'FT2' },
+    { mhz: 21.144, mode: 'FT2' },
+    { mhz: 24.923, mode: 'FT2' },
+    { mhz: 28.184, mode: 'FT2' },
     // FT4 calling frequencies
     { mhz: 3.575, mode: 'FT4' },
     { mhz: 7.0475, mode: 'FT4' },
@@ -145,9 +166,8 @@ export const detectMode = (comment, freq) => {
   ];
 
   for (const island of DIGITAL_ISLANDS) {
-    if (Math.abs(mhz - island.mhz) <= TOLERANCE) {
-      return island.mode;
-    }
+    const offset = mhz - island.mhz;
+    if (offset >= -0.0005 && offset <= 0.0031) return island.mode;
   }
 
   // Band plan segments — CW vs SSB by frequency range

src/utils/callsign.test.js

@@ -0,0 +1,43 @@
+import { describe, expect, it } from 'vitest';
+
+import { detectMode } from './callsign.js';
+
+// FTx signals occupy dial + 0–3 kHz (audio passband above the dial), so the
+// island window is asymmetric: [dial − 0.5 kHz, dial + 3.1 kHz]. These tests
+// pin the boundaries — especially FT4 vs FT2, whose dials are only 4 kHz
+// apart, which is why a symmetric ±5 kHz window can never work.
+describe('detectMode frequency islands (asymmetric window)', () => {
+  it('classifies spots in the audio passband above the dial', () => {
+    expect(detectMode(null, '14.074')).toBe('FT8'); // 20m FT8 dial itself
+    expect(detectMode(null, '14.077')).toBe('FT8'); // near top of passband
+    expect(detectMode(null, '14.081')).toBe('FT4'); // FT4 dial + 1 kHz
+    expect(detectMode(null, '14.085')).toBe('FT2'); // FT2 dial + 1 kHz
+    expect(detectMode(null, '24.916')).toBe('FT8'); // 12m FT8 dial + 1 kHz
+    expect(detectMode(null, '24.924')).toBe('FT2'); // 12m FT2 dial + 1 kHz
+  });
+
+  it('does not classify below-dial spots as FTx — signals are never below the dial', () => {
+    // 24.911 is 4 kHz below the 12m FT8 dial (24.915). The old ±5 kHz window
+    // matched it (see the retired comment in callsign.js), but such spots are
+    // busted: the FT8 audio passband sits entirely above the dial.
+    expect(detectMode(null, '24.911')).not.toBe('FT8');
+  });
+
+  it('separates FT4 and FT2 islands only 4 kHz apart', () => {
+    expect(detectMode(null, '14.083')).toBe('FT4'); // FT4 dial + 3.0 kHz
+    expect(detectMode(null, '14.0835')).toBe('FT2'); // FT2 dial − 0.5 kHz (rounded-down allowance)
+  });
+
+  it('160m FT8/FT2 dial adjacency: FT8 wins bare dial quotes, comments win everything', () => {
+    // FT2's 1.843 dial sits exactly at the top of FT8 1.840's passband — the
+    // documented, inherent ambiguity. A bare spot at exactly the FT2 dial
+    // classifies FT8; anything above it is FT2; a comment overrides both.
+    expect(detectMode(null, '1.8430')).toBe('FT8');
+    expect(detectMode(null, '1.8432')).toBe('FT2');
+    expect(detectMode('FT2 -12dB from JN44 1489Hz', '1.843')).toBe('FT2');
+  });
+
+  it('normalizes spots arriving in kHz', () => {
+    expect(detectMode(null, '14085')).toBe('FT2');
+  });
+});

src/utils/propagationAdjust.js

@@ -13,6 +13,10 @@ export const MODE_ADVANTAGE_DB = {
   PSK31: 10,
   FT8: 34,
   FT4: 30,
+  // FT2 trades sensitivity for speed: decode threshold is -12/-13 dB vs
+  // FT4's -17.5 and FT8's -21 (ft2.it technical document) — the LEAST
+  // sensitive of the FTx modes despite being the fastest.
+  FT2: 25,
   WSPR: 41,
   JS8: 37,
   OLIVIA: 20,