Finding signals

Library → Occupancy shows how busy each frequency on the selected Device has been, hour by hour.

Scan

A Scanner drives one channel, never the radio. On auto tuning the radio follows the channel. Tuned by hand, the radio stays put and the scan skips targets outside its window. The Scanner keeps its settings, lockouts and priority frequencies.

1. Add a channel in the mode you want to hear and wire it to a Speaker.
2. Add Scanner, wire its control to the channel's control and the channel's Device iq to its iq. A scanner watching a different lane from its channel is refused. Removing the control wire stops the scan.
3. Pick a Band, or set each range's From, To and Step. Add range adds another.
4. Pick what to Find and press Start scan.

Busy means at least Over noise above the noise floor (default 12 dB), measured over the channel's own bandwidth. Match the step to the service's channel spacing.

Band lists the bands of the band plan region that have a channel raster. Bands with named channels, such as DAB blocks 5A to 12D or PMR446, scan exactly those channels.

On a hit the channel parks there so you hear it. The scan resumes after 1.5 s of quiet. Skip leaves the current frequency and adds it to Lockouts. Priority frequencies are checked every 2 s and win over anything else, also during a hold when the radio's window covers them. The channel's dial is locked while scanning, and stays on the last frequency after Stop scan.

List every station

The decoder reads the station, not the scanner. To list every DAB ensemble:

1. Wire Scanner → DAB channel → Decoder log.
2. Pick the Band with the DAB blocks, Find All, Hold 5 s.
3. Press Start scan. Each busy block is visited once and the log fills with what the DAB channel decodes there.

Read back a scan

Wire the scanned channel's events to a Decoder log and set its Group:

An analog channel logs each squelch opening as a call, so Frequency shows how often and how long each frequency was busy. Click Frequency, Hits or Last to sort, and a row to play its latest call. The log node keeps its grouping.

Radios that support it sweep in firmware, shown as Firmware sweep (on by default). Other channels on that radio pause while it runs. It is refused while the radio records IQ, holds a pre-roll or exports IQ. The Sweep readout shows the radio's own or by retuning.

Identify a signal

Add Signal identifier from the Utility channels. It lists each transmission in its window, strongest first, with modulation, bandwidth, SNR, symbol rate, deviation, and burst timing.

For each signal it suggests likely protocols. A suggestion marked confirmed was proven by a decoder or a frame sync found in the signal. The others are guesses from the waveform and the band. A quiet span is reported once, not every interval.

It cannot see signals below the noise, such as spread spectrum, or separate tightly packed HF signals like FT8.

Monitor a band

Wire Device iq → Spectrum monitor → Decoder log. The monitor watches the Device's whole window, finds every transmission, and tries the matching decoders on each one. It adds no channel nodes and never tunes the radio.

Protocols picks what it decodes. Everything is on by default. Pick a preset such as Analog voice, or toggle single protocols. Off protocols are skipped, not logged. Unidentified signals also logs transmissions no protocol matches. Start and Stop limit it to part of the window. Leave them empty to watch all of it.

Decoded messages arrive as they happen. Each transmission also gives one event when it ends, with frequency, bandwidth, confidence, the decoder used, and optional audio. Long transmissions report every 30 seconds. Open an event in the log to play the audio.

Wire the monitor's events to a Decoder log to attach an 8 kHz WAV clip to each transmission. Clips stay for up to 24 hours. To keep them, also wire events to an Event output set to Recordings.

Limits: 32 signals at once, three decoders at a time per signal, two seconds of IQ kept for late decoders. Anything dropped is reported. Pictures and video are not decoded here.

Hunt a transmitter

Signal hunt reads one channel's signal strength fast enough to walk with. Wire its control to the channel's control, the channel's Device iq to its iq, and press Start hunt. Retune the channel to retune the hunt. With Clicks on, Geiger clicks speed up as the signal gets stronger.

Sweep for a bearing

With a directional antenna and a phone you get bearings, not only warmer and colder:

1. Wire a GPS node with the Phone source to the hunt's position.
2. Hold the antenna and the phone together. Mount sets the antenna's direction relative to the phone.
3. Press Sweep and turn slowly all the way round. The rose fills in and Peak shows the strongest direction.
4. When Sweep reads Done, the bearing is sent on events.

Mark sends the direction you face as a bearing. Wire events to a Triangulation to cross bearings from several places. End sweep goes back to warmer and colder.

Survey an area

1. Add Signal survey and wire Device iq and GPS position to it.
2. Set Offset inside the Device's window and a measurement Width.
3. Wait for a level and a GPS fix, then press Start survey.
4. Press Export CSV when done.

Each GPS fix records the peak level in dBFS within the slice, averaged into cells of about ten metres. Keep gain, antenna, and width the same, or the numbers will not compare. Pause before you change the receiver. Offset and width are fixed until you Clear the survey.

The server keeps surveying with the page closed, so a phone can run it as a Survey mission. It keeps up to 5,000 cells in memory and drops the oldest beyond that. A server restart loses them.