Introduction

The Detector app is based on the Level app and allows quick signal detection across preset frequency lists for LoRa, remote controls, and TETRA uplink. It scans through all frequencies in the selected preset automatically, and produces an audible beep whenever a signal exceeds the configured threshold.

Controls

First line — Gain and Volume

• LNA — IF gain (0–40 dB). Adjust with rotary encoder when focused.
• VGA — Baseband gain (0–62 dB). Adjust with rotary encoder when focused.
• AMP — RF amplifier: 0 = off, 1 = on (+14 dB).
• VOL — Beep volume (0–99).

Second line — Preset selection

Select the signal type to monitor:

Preset	Frequency range	Description
TETRA UP	380–390 MHz	TETRA uplink band (emergency services, Europe)
Lora	433, 868, 915 MHz	LoRaWAN EU433, EU868 and US915 bands
Remotes	315, 433.92 MHz	Common remote control and key fob frequencies

The current frequency being scanned is displayed on the right side of this line.

Third line — Beep threshold and signal display

• Bip — Detection threshold in dBm (-100 to +20). When the received signal power exceeds this value, a beep is triggered. Lower values = more sensitive. The beep pitch scales with signal strength: a weak signal at threshold produces a 400 Hz tone, a maximum strength signal (+20 dBm) produces a 2600 Hz tone. Beep duration is 150 ms.
• RSSI: min/avg/max — Raw RSSI values (min/average/max) from the RSSI graph over recent history.
• Power: -XX db — Current received signal power in dBm.

How scanning works

The app cycles through all frequencies in the selected preset on every display frame (~16 ms per frequency step). Each scan window has a bandwidth of 750 kHz. If the signal level on any frequency exceeds the threshold during its scan window, a beep is produced.

Signal display

The main area shows two displays:

• RSSI graph — scrolling history of min/avg/max RSSI values and signal power
• RSSI bar — current instantaneous RSSI level on the right side

Preset frequencies

Remotes

Center frequency	Coverage
315.000 MHz	314.625 – 315.375 MHz
433.920 MHz	433.545 – 434.295 MHz

LoRa

Center frequency	Coverage	Band
433.375 MHz	433.000 – 433.750 MHz	EU433
434.125 MHz	433.750 – 434.500 MHz	EU433
434.875 MHz	434.500 – 435.250 MHz	EU433
867.375 MHz	867.000 – 867.750 MHz	EU868
868.125 MHz	867.750 – 868.500 MHz	EU868
868.875 MHz	868.500 – 869.250 MHz	EU868
914.250 MHz	913.875 – 914.625 MHz	US915
915.000 MHz	914.625 – 915.375 MHz	US915
915.750 MHz	915.375 – 916.125 MHz	US915

TETRA Uplink

Center frequency	Coverage
380.375 MHz	380.000 – 380.750 MHz
381.125 MHz	380.750 – 381.500 MHz
381.875 MHz	381.500 – 382.250 MHz
382.625 MHz	382.250 – 383.000 MHz
383.375 MHz	383.000 – 383.750 MHz
384.125 MHz	383.750 – 384.500 MHz
384.875 MHz	384.500 – 385.250 MHz
385.625 MHz	385.250 – 386.000 MHz
386.375 MHz	386.000 – 386.750 MHz
387.125 MHz	386.750 – 387.500 MHz
387.875 MHz	387.500 – 388.250 MHz
388.625 MHz	388.250 – 389.000 MHz
389.375 MHz	389.000 – 389.750 MHz
390.125 MHz	389.750 – 390.500 MHz

Settings

The beep threshold is saved automatically to SETTINGS/rx_detector.ini on the SD card when the app is closed (requires Load App Settings to be enabled in the Settings menu).