diff --git a/routes/wefax.py b/routes/wefax.py
index ccce86d..497cdf0 100644
--- a/routes/wefax.py
+++ b/routes/wefax.py
@@ -11,17 +11,18 @@ import queue
from flask import Blueprint, Response, jsonify, request, send_file
import app as app_module
-from utils.logging import get_logger
-from utils.sse import sse_stream_fanout
-from utils.validation import validate_frequency
-from utils.wefax import get_wefax_decoder
-from utils.wefax_stations import (
- WEFAX_USB_ALIGNMENT_OFFSET_KHZ,
- get_current_broadcasts,
- get_station,
- load_stations,
- resolve_tuning_frequency_khz,
-)
+from utils.logging import get_logger
+from utils.sdr import SDRType
+from utils.sse import sse_stream_fanout
+from utils.validation import validate_frequency
+from utils.wefax import get_wefax_decoder
+from utils.wefax_stations import (
+ WEFAX_USB_ALIGNMENT_OFFSET_KHZ,
+ get_current_broadcasts,
+ get_station,
+ load_stations,
+ resolve_tuning_frequency_khz,
+)
logger = get_logger('intercept.wefax')
@@ -34,29 +35,29 @@ _wefax_queue: queue.Queue = queue.Queue(maxsize=100)
wefax_active_device: int | None = None
-def _progress_callback(data: dict) -> None:
- """Callback to queue progress updates for SSE stream."""
- global wefax_active_device
-
- try:
- _wefax_queue.put_nowait(data)
- except queue.Full:
- try:
- _wefax_queue.get_nowait()
- _wefax_queue.put_nowait(data)
- except queue.Empty:
- pass
-
- # Ensure manually claimed SDR devices are always released when a
- # decode session ends on its own (complete/error/stopped).
- if (
- isinstance(data, dict)
- and data.get('type') == 'wefax_progress'
- and data.get('status') in ('complete', 'error', 'stopped')
- and wefax_active_device is not None
- ):
- app_module.release_sdr_device(wefax_active_device)
- wefax_active_device = None
+def _progress_callback(data: dict) -> None:
+ """Callback to queue progress updates for SSE stream."""
+ global wefax_active_device
+
+ try:
+ _wefax_queue.put_nowait(data)
+ except queue.Full:
+ try:
+ _wefax_queue.get_nowait()
+ _wefax_queue.put_nowait(data)
+ except queue.Empty:
+ pass
+
+ # Ensure manually claimed SDR devices are always released when a
+ # decode session ends on its own (complete/error/stopped).
+ if (
+ isinstance(data, dict)
+ and data.get('type') == 'wefax_progress'
+ and data.get('status') in ('complete', 'error', 'stopped')
+ and wefax_active_device is not None
+ ):
+ app_module.release_sdr_device(wefax_active_device)
+ wefax_active_device = None
@wefax_bp.route('/status')
@@ -75,16 +76,16 @@ def start_decoder():
"""Start WeFax decoder.
JSON body:
- {
- "frequency_khz": 4298,
- "station": "NOJ",
- "device": 0,
- "gain": 40,
- "ioc": 576,
- "lpm": 120,
- "direct_sampling": true,
- "frequency_reference": "auto" // auto, carrier, or dial
- }
+ {
+ "frequency_khz": 4298,
+ "station": "NOJ",
+ "device": 0,
+ "gain": 40,
+ "ioc": 576,
+ "lpm": 120,
+ "direct_sampling": true,
+ "frequency_reference": "auto" // auto, carrier, or dial
+ }
"""
decoder = get_wefax_decoder()
@@ -122,36 +123,42 @@ def start_decoder():
'message': f'Invalid frequency: {e}',
}), 400
- station = str(data.get('station', '')).strip()
- device_index = data.get('device', 0)
- gain = float(data.get('gain', 40.0))
- ioc = int(data.get('ioc', 576))
- lpm = int(data.get('lpm', 120))
- direct_sampling = bool(data.get('direct_sampling', True))
- frequency_reference = str(data.get('frequency_reference', 'auto')).strip().lower()
- if not frequency_reference:
- frequency_reference = 'auto'
-
- try:
- tuned_frequency_khz, resolved_reference, usb_offset_applied = (
- resolve_tuning_frequency_khz(
- listed_frequency_khz=frequency_khz,
- station_callsign=station,
- frequency_reference=frequency_reference,
- )
- )
- tuned_mhz = tuned_frequency_khz / 1000.0
- validate_frequency(tuned_mhz, min_mhz=2.0, max_mhz=30.0)
- except ValueError as e:
- return jsonify({
- 'status': 'error',
- 'message': f'Invalid frequency settings: {e}',
- }), 400
-
- # Validate IOC and LPM
- if ioc not in (288, 576):
- return jsonify({
- 'status': 'error',
+ station = str(data.get('station', '')).strip()
+ device_index = data.get('device', 0)
+ gain = float(data.get('gain', 40.0))
+ ioc = int(data.get('ioc', 576))
+ lpm = int(data.get('lpm', 120))
+ direct_sampling = bool(data.get('direct_sampling', True))
+ frequency_reference = str(data.get('frequency_reference', 'auto')).strip().lower()
+
+ sdr_type_str = str(data.get('sdr_type', 'rtlsdr')).lower()
+ try:
+ sdr_type = SDRType(sdr_type_str)
+ except ValueError:
+ sdr_type = SDRType.RTL_SDR
+ if not frequency_reference:
+ frequency_reference = 'auto'
+
+ try:
+ tuned_frequency_khz, resolved_reference, usb_offset_applied = (
+ resolve_tuning_frequency_khz(
+ listed_frequency_khz=frequency_khz,
+ station_callsign=station,
+ frequency_reference=frequency_reference,
+ )
+ )
+ tuned_mhz = tuned_frequency_khz / 1000.0
+ validate_frequency(tuned_mhz, min_mhz=2.0, max_mhz=30.0)
+ except ValueError as e:
+ return jsonify({
+ 'status': 'error',
+ 'message': f'Invalid frequency settings: {e}',
+ }), 400
+
+ # Validate IOC and LPM
+ if ioc not in (288, 576):
+ return jsonify({
+ 'status': 'error',
'message': 'IOC must be 288 or 576',
}), 400
@@ -172,34 +179,35 @@ def start_decoder():
'message': error,
}), 409
- # Set callback and start
- decoder.set_callback(_progress_callback)
- success = decoder.start(
- frequency_khz=tuned_frequency_khz,
- station=station,
- device_index=device_int,
- gain=gain,
- ioc=ioc,
- lpm=lpm,
+ # Set callback and start
+ decoder.set_callback(_progress_callback)
+ success = decoder.start(
+ frequency_khz=tuned_frequency_khz,
+ station=station,
+ device_index=device_int,
+ gain=gain,
+ ioc=ioc,
+ lpm=lpm,
direct_sampling=direct_sampling,
+ sdr_type=sdr_type_str,
)
if success:
wefax_active_device = device_int
- return jsonify({
- 'status': 'started',
- 'frequency_khz': frequency_khz,
- 'tuned_frequency_khz': tuned_frequency_khz,
- 'frequency_reference': resolved_reference,
- 'usb_offset_applied': usb_offset_applied,
- 'usb_offset_khz': (
- WEFAX_USB_ALIGNMENT_OFFSET_KHZ if usb_offset_applied else 0.0
- ),
- 'station': station,
- 'ioc': ioc,
- 'lpm': lpm,
- 'device': device_int,
- })
+ return jsonify({
+ 'status': 'started',
+ 'frequency_khz': frequency_khz,
+ 'tuned_frequency_khz': tuned_frequency_khz,
+ 'frequency_reference': resolved_reference,
+ 'usb_offset_applied': usb_offset_applied,
+ 'usb_offset_khz': (
+ WEFAX_USB_ALIGNMENT_OFFSET_KHZ if usb_offset_applied else 0.0
+ ),
+ 'station': station,
+ 'ioc': ioc,
+ 'lpm': lpm,
+ 'device': device_int,
+ })
else:
app_module.release_sdr_device(device_int)
return jsonify({
@@ -322,16 +330,16 @@ def enable_schedule():
"""Enable auto-scheduling of WeFax broadcast captures.
JSON body:
- {
- "station": "NOJ",
- "frequency_khz": 4298,
- "device": 0,
- "gain": 40,
- "ioc": 576,
- "lpm": 120,
- "direct_sampling": true,
- "frequency_reference": "auto" // auto, carrier, or dial
- }
+ {
+ "station": "NOJ",
+ "frequency_khz": 4298,
+ "device": 0,
+ "gain": 40,
+ "ioc": 576,
+ "lpm": 120,
+ "direct_sampling": true,
+ "frequency_reference": "auto" // auto, carrier, or dial
+ }
Returns:
JSON with scheduler status.
@@ -365,61 +373,61 @@ def enable_schedule():
}), 400
device = int(data.get('device', 0))
- gain = float(data.get('gain', 40.0))
- ioc = int(data.get('ioc', 576))
- lpm = int(data.get('lpm', 120))
- direct_sampling = bool(data.get('direct_sampling', True))
- frequency_reference = str(data.get('frequency_reference', 'auto')).strip().lower()
- if not frequency_reference:
- frequency_reference = 'auto'
-
- try:
- tuned_frequency_khz, resolved_reference, usb_offset_applied = (
- resolve_tuning_frequency_khz(
- listed_frequency_khz=frequency_khz,
- station_callsign=station,
- frequency_reference=frequency_reference,
- )
- )
- tuned_mhz = tuned_frequency_khz / 1000.0
- validate_frequency(tuned_mhz, min_mhz=2.0, max_mhz=30.0)
- except ValueError as e:
- return jsonify({
- 'status': 'error',
- 'message': f'Invalid frequency settings: {e}',
- }), 400
-
- scheduler = get_wefax_scheduler()
- scheduler.set_callbacks(_progress_callback, _scheduler_event_callback)
-
- try:
- result = scheduler.enable(
- station=station,
- frequency_khz=tuned_frequency_khz,
- device=device,
- gain=gain,
- ioc=ioc,
- lpm=lpm,
- direct_sampling=direct_sampling,
+ gain = float(data.get('gain', 40.0))
+ ioc = int(data.get('ioc', 576))
+ lpm = int(data.get('lpm', 120))
+ direct_sampling = bool(data.get('direct_sampling', True))
+ frequency_reference = str(data.get('frequency_reference', 'auto')).strip().lower()
+ if not frequency_reference:
+ frequency_reference = 'auto'
+
+ try:
+ tuned_frequency_khz, resolved_reference, usb_offset_applied = (
+ resolve_tuning_frequency_khz(
+ listed_frequency_khz=frequency_khz,
+ station_callsign=station,
+ frequency_reference=frequency_reference,
+ )
+ )
+ tuned_mhz = tuned_frequency_khz / 1000.0
+ validate_frequency(tuned_mhz, min_mhz=2.0, max_mhz=30.0)
+ except ValueError as e:
+ return jsonify({
+ 'status': 'error',
+ 'message': f'Invalid frequency settings: {e}',
+ }), 400
+
+ scheduler = get_wefax_scheduler()
+ scheduler.set_callbacks(_progress_callback, _scheduler_event_callback)
+
+ try:
+ result = scheduler.enable(
+ station=station,
+ frequency_khz=tuned_frequency_khz,
+ device=device,
+ gain=gain,
+ ioc=ioc,
+ lpm=lpm,
+ direct_sampling=direct_sampling,
)
except Exception:
logger.exception("Failed to enable WeFax scheduler")
- return jsonify({
- 'status': 'error',
- 'message': 'Failed to enable scheduler',
- }), 500
-
- return jsonify({
- 'status': 'ok',
- **result,
- 'frequency_khz': frequency_khz,
- 'tuned_frequency_khz': tuned_frequency_khz,
- 'frequency_reference': resolved_reference,
- 'usb_offset_applied': usb_offset_applied,
- 'usb_offset_khz': (
- WEFAX_USB_ALIGNMENT_OFFSET_KHZ if usb_offset_applied else 0.0
- ),
- })
+ return jsonify({
+ 'status': 'error',
+ 'message': 'Failed to enable scheduler',
+ }), 500
+
+ return jsonify({
+ 'status': 'ok',
+ **result,
+ 'frequency_khz': frequency_khz,
+ 'tuned_frequency_khz': tuned_frequency_khz,
+ 'frequency_reference': resolved_reference,
+ 'usb_offset_applied': usb_offset_applied,
+ 'usb_offset_khz': (
+ WEFAX_USB_ALIGNMENT_OFFSET_KHZ if usb_offset_applied else 0.0
+ ),
+ })
@wefax_bp.route('/schedule/disable', methods=['POST'])
diff --git a/static/js/modes/wefax.js b/static/js/modes/wefax.js
index 3499af4..853bc72 100644
--- a/static/js/modes/wefax.js
+++ b/static/js/modes/wefax.js
@@ -148,20 +148,20 @@ var WeFax = (function () {
opt.textContent = f.khz + ' kHz — ' + f.description;
sel.appendChild(opt);
});
- }
-
- // ---- Start / Stop ----
-
- function selectedFrequencyReference() {
- var alignCheckbox = document.getElementById('wefaxAutoUsbAlign');
- if (alignCheckbox && !alignCheckbox.checked) {
- return 'dial';
- }
- return 'auto';
- }
-
- function start() {
- if (state.running) return;
+ }
+
+ // ---- Start / Stop ----
+
+ function selectedFrequencyReference() {
+ var alignCheckbox = document.getElementById('wefaxAutoUsbAlign');
+ if (alignCheckbox && !alignCheckbox.checked) {
+ return 'dial';
+ }
+ return 'auto';
+ }
+
+ function start() {
+ if (state.running) return;
var freqSel = document.getElementById('wefaxFrequency');
var freqKhz = freqSel ? parseFloat(freqSel.value) : 0;
@@ -177,41 +177,42 @@ var WeFax = (function () {
var gainInput = document.getElementById('wefaxGain');
var dsCheckbox = document.getElementById('wefaxDirectSampling');
- var deviceSel = document.getElementById('rtlDevice');
- var device = deviceSel ? parseInt(deviceSel.value, 10) || 0 : 0;
+ var device = (typeof getSelectedDevice === 'function')
+ ? parseInt(getSelectedDevice(), 10) || 0 : 0;
var body = {
frequency_khz: freqKhz,
station: station,
device: device,
- gain: gainInput ? parseFloat(gainInput.value) || 40 : 40,
- ioc: iocSel ? parseInt(iocSel.value, 10) : 576,
- lpm: lpmSel ? parseInt(lpmSel.value, 10) : 120,
- direct_sampling: dsCheckbox ? dsCheckbox.checked : true,
- frequency_reference: selectedFrequencyReference(),
- };
+ sdr_type: (typeof getSelectedSDRType === 'function') ? getSelectedSDRType() : 'rtlsdr',
+ gain: gainInput ? parseFloat(gainInput.value) || 40 : 40,
+ ioc: iocSel ? parseInt(iocSel.value, 10) : 576,
+ lpm: lpmSel ? parseInt(lpmSel.value, 10) : 120,
+ direct_sampling: dsCheckbox ? dsCheckbox.checked : true,
+ frequency_reference: selectedFrequencyReference(),
+ };
fetch('/wefax/start', {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify(body),
})
- .then(function (r) { return r.json(); })
- .then(function (data) {
- if (data.status === 'started' || data.status === 'already_running') {
- var tunedKhz = Number(data.tuned_frequency_khz);
- if (isNaN(tunedKhz) || tunedKhz <= 0) tunedKhz = freqKhz;
- state.running = true;
- updateButtons(true);
- if (data.usb_offset_applied) {
- setStatus('Scanning ' + tunedKhz + ' kHz (USB aligned from ' + freqKhz + ' kHz)...');
- } else {
- setStatus('Scanning ' + tunedKhz + ' kHz...');
- }
- setStripFreq(tunedKhz);
- connectSSE();
- } else {
- var errMsg = data.message || 'unknown error';
+ .then(function (r) { return r.json(); })
+ .then(function (data) {
+ if (data.status === 'started' || data.status === 'already_running') {
+ var tunedKhz = Number(data.tuned_frequency_khz);
+ if (isNaN(tunedKhz) || tunedKhz <= 0) tunedKhz = freqKhz;
+ state.running = true;
+ updateButtons(true);
+ if (data.usb_offset_applied) {
+ setStatus('Scanning ' + tunedKhz + ' kHz (USB aligned from ' + freqKhz + ' kHz)...');
+ } else {
+ setStatus('Scanning ' + tunedKhz + ' kHz...');
+ }
+ setStripFreq(tunedKhz);
+ connectSSE();
+ } else {
+ var errMsg = data.message || 'unknown error';
setStatus('Error: ' + errMsg);
showStripError(errMsg);
}
@@ -342,25 +343,25 @@ var WeFax = (function () {
if (idleEl) idleEl.style.display = 'none';
}
- // Image complete
- if (data.status === 'complete' && data.image) {
- scopeImageBurst = 1.0;
- loadImages();
- setStatus('Image decoded: ' + (data.line_count || '?') + ' lines');
- }
-
- if (data.status === 'complete') {
- state.running = false;
- updateButtons(false);
- if (!state.schedulerEnabled) {
- disconnectSSE();
- }
- }
-
- if (data.status === 'error') {
- state.running = false;
- updateButtons(false);
- showStripError(data.message || 'Decode error');
+ // Image complete
+ if (data.status === 'complete' && data.image) {
+ scopeImageBurst = 1.0;
+ loadImages();
+ setStatus('Image decoded: ' + (data.line_count || '?') + ' lines');
+ }
+
+ if (data.status === 'complete') {
+ state.running = false;
+ updateButtons(false);
+ if (!state.schedulerEnabled) {
+ disconnectSSE();
+ }
+ }
+
+ if (data.status === 'error') {
+ state.running = false;
+ updateButtons(false);
+ showStripError(data.message || 'Decode error');
}
if (data.status === 'stopped') {
@@ -1062,24 +1063,24 @@ var WeFax = (function () {
station: station,
frequency_khz: freqKhz,
device: device,
- gain: gainInput ? parseFloat(gainInput.value) || 40 : 40,
- ioc: iocSel ? parseInt(iocSel.value, 10) : 576,
- lpm: lpmSel ? parseInt(lpmSel.value, 10) : 120,
- direct_sampling: dsCheckbox ? dsCheckbox.checked : true,
- frequency_reference: selectedFrequencyReference(),
- }),
- })
- .then(function (r) { return r.json(); })
- .then(function (data) {
- if (data.status === 'ok') {
- var status = 'Auto-capture enabled — ' + (data.scheduled_count || 0) + ' broadcasts scheduled';
- if (data.usb_offset_applied && !isNaN(Number(data.tuned_frequency_khz))) {
- status += ' (tuning ' + Number(data.tuned_frequency_khz) + ' kHz)';
- }
- setStatus(status);
- syncSchedulerCheckboxes(true);
- state.schedulerEnabled = true;
- connectSSE();
+ gain: gainInput ? parseFloat(gainInput.value) || 40 : 40,
+ ioc: iocSel ? parseInt(iocSel.value, 10) : 576,
+ lpm: lpmSel ? parseInt(lpmSel.value, 10) : 120,
+ direct_sampling: dsCheckbox ? dsCheckbox.checked : true,
+ frequency_reference: selectedFrequencyReference(),
+ }),
+ })
+ .then(function (r) { return r.json(); })
+ .then(function (data) {
+ if (data.status === 'ok') {
+ var status = 'Auto-capture enabled — ' + (data.scheduled_count || 0) + ' broadcasts scheduled';
+ if (data.usb_offset_applied && !isNaN(Number(data.tuned_frequency_khz))) {
+ status += ' (tuning ' + Number(data.tuned_frequency_khz) + ' kHz)';
+ }
+ setStatus(status);
+ syncSchedulerCheckboxes(true);
+ state.schedulerEnabled = true;
+ connectSSE();
startSchedulerPoll();
} else {
setStatus('Scheduler error: ' + (data.message || 'unknown'));
diff --git a/templates/partials/modes/wefax.html b/templates/partials/modes/wefax.html
index e0dd170..55b3e50 100644
--- a/templates/partials/modes/wefax.html
+++ b/templates/partials/modes/wefax.html
@@ -44,18 +44,18 @@
-
-
-
-
-
-
-
-
-
- Disable this if your source already provides USB dial frequencies.
-
-
+
+
+
+
+
+
+
+
+
+ Disable this if your source already provides USB dial frequencies.
+
+
Auto Capture
@@ -80,7 +80,7 @@
Requirements
- - SDR: RTL-SDR v3/v4 with direct sampling mode
+ - SDR: RTL-SDR (direct sampling), HackRF, LimeSDR, Airspy, or SDRPlay
- Antenna: Long wire (10m+), random wire, or dipole for target band
- Mode: USB (Upper Sideband) demodulation
- Signals: Moderate — HF propagation varies by time of day
diff --git a/utils/wefax.py b/utils/wefax.py
index cf457d3..8733f3c 100644
--- a/utils/wefax.py
+++ b/utils/wefax.py
@@ -1,10 +1,11 @@
"""WeFax (Weather Fax) decoder.
-Decodes HF radiofax (weather fax) transmissions using RTL-SDR direct
-sampling mode. The decoder implements the standard WeFax AM protocol:
+Decodes HF radiofax (weather fax) transmissions using any supported SDR
+(RTL-SDR, HackRF, LimeSDR, Airspy, SDRPlay) via the SDRFactory
+abstraction layer. The decoder implements the standard WeFax AM protocol:
carrier 1900 Hz, deviation +/-400 Hz (black=1500, white=2300).
-Pipeline: rtl_fm -M usb -E direct2 -> stdout PCM -> Python DSP state machine
+Pipeline: rtl_fm/rx_fm -M usb -> stdout PCM -> Python DSP state machine
State machine: SCANNING -> PHASING -> RECEIVING -> COMPLETE
"""
@@ -30,6 +31,7 @@ import numpy as np
from utils.dependencies import get_tool_path
from utils.logging import get_logger
+from utils.sdr import SDRFactory, SDRType
logger = get_logger('intercept.wefax')
@@ -262,17 +264,19 @@ class WeFaxDecoder:
ioc: int = DEFAULT_IOC,
lpm: int = DEFAULT_LPM,
direct_sampling: bool = True,
+ sdr_type: str = 'rtlsdr',
) -> bool:
"""Start WeFax decoder.
Args:
frequency_khz: Frequency in kHz (e.g. 4298 for NOJ).
station: Station callsign for metadata.
- device_index: RTL-SDR device index.
+ device_index: SDR device index.
gain: Receiver gain in dB.
ioc: Index of Cooperation (576 or 288).
lpm: Lines per minute (120 or 60).
direct_sampling: Enable RTL-SDR direct sampling for HF.
+ sdr_type: SDR hardware type (rtlsdr, hackrf, limesdr, airspy, sdrplay).
Returns:
True if started successfully.
@@ -288,6 +292,7 @@ class WeFaxDecoder:
self._device_index = device_index
self._gain = gain
self._direct_sampling = direct_sampling
+ self._sdr_type = sdr_type
self._sample_rate = DEFAULT_SAMPLE_RATE
try:
@@ -312,27 +317,39 @@ class WeFaxDecoder:
return False
def _start_pipeline(self) -> None:
- """Start rtl_fm subprocess in USB mode for WeFax."""
- rtl_fm_path = get_tool_path('rtl_fm')
- if not rtl_fm_path:
- raise RuntimeError('rtl_fm not found')
+ """Start SDR FM demod subprocess in USB mode for WeFax."""
+ try:
+ sdr_type_enum = SDRType(self._sdr_type)
+ except ValueError:
+ sdr_type_enum = SDRType.RTL_SDR
- freq_hz = int(self._frequency_khz * 1000)
+ # Validate that the required tool is available
+ if sdr_type_enum == SDRType.RTL_SDR:
+ if not get_tool_path('rtl_fm'):
+ raise RuntimeError('rtl_fm not found')
+ else:
+ if not get_tool_path('rx_fm'):
+ raise RuntimeError('rx_fm not found (required for non-RTL-SDR devices)')
- rtl_cmd = [
- rtl_fm_path,
- '-d', str(self._device_index),
- '-f', str(freq_hz),
- '-M', 'usb',
- '-s', str(self._sample_rate),
- '-r', str(self._sample_rate),
- '-g', str(self._gain),
- ]
+ sdr_device = SDRFactory.create_default_device(
+ sdr_type_enum, index=self._device_index)
+ builder = SDRFactory.get_builder(sdr_type_enum)
+ rtl_cmd = builder.build_fm_demod_command(
+ device=sdr_device,
+ frequency_mhz=self._frequency_khz / 1000.0,
+ sample_rate=self._sample_rate,
+ gain=self._gain,
+ modulation='usb',
+ )
- if self._direct_sampling:
- rtl_cmd.extend(['-E', 'direct2'])
-
- rtl_cmd.append('-')
+ # RTL-SDR: append direct sampling flag for HF reception
+ if sdr_type_enum == SDRType.RTL_SDR and self._direct_sampling:
+ # Insert before trailing '-' stdout marker
+ if rtl_cmd and rtl_cmd[-1] == '-':
+ rtl_cmd.insert(-1, '-E')
+ rtl_cmd.insert(-1, 'direct2')
+ else:
+ rtl_cmd.extend(['-E', 'direct2', '-'])
logger.info(f"Starting rtl_fm: {' '.join(rtl_cmd)}")