SWLtools vs EMF Detector

SWLtools: The Companion for Shortwave Listening Enthusiasts SWLtools is an app designed specifically for Shortwave Listening (SWL) enthusiasts who want to enhance their listening experience. It records what you hear, shows you the band, and reads the digital modes that carry text on the air. Whether you are a hobbyist or a dedicated DXer, SWLtools supports your activity from the antenna to the logbook. DECODING THE ON-AIR TEXT MODES Point the app at a signal and it turns it into readable text. - Morse (CW). The app follows the tone by itself and measures the sending speed from the signal, so it keeps up with hand-sent Morse as well as machine-sent. A side panel collects the callsigns it has heard, and each transmission starts on its own line when the operator hands over. - RTTY, in both ITA2 and SITOR-B. - Weather fax (WEFAX). The chart builds up line by line as it arrives, and can be saved straight to your photo library. - ACARS aircraft messages, with the ones carrying a position shown on a map. Decoded text can be saved, reopened later and shared. All times, on screen and in the saved files, are UTC — the way radio logs are kept. SPECTRUM AND WATERFALL If your receiver provides an IQ output, SWLtools displays the real-time spectrum and spectrogram. Visually explore the bands and gain deeper insight into the signals you are receiving. Where the two channels of a USB adapter do not arrive perfectly in step — a common trait of audio codecs — a sample-delay correction removes the mirror image that would otherwise appear beside every signal. AUDIO RECORDING AND STORAGE Easily record and store audio directly from your receiver. Capture signals from around the world and listen to them again whenever you want, or turn a recording into a video to share. OPTIMIZED FOR THE BELKA RECEIVER SWLtools was designed to work seamlessly with the Belka receiver. It is the perfect companion for outdoor listening sessions, letting you record your DX, explore frequencies with the spectrum view, or read a weather fax from the field. The app is optimized for low power consumption when displaying the spectrum and waterfall, making it ideal for portable use. REQUIREMENTS To use SWLtools you need an inexpensive USB audio adapter (ADC/DAC) connected to your iOS device. These affordable dongles typically provide a microphone input and a headphone output, which is enough to record, to decode, and to show a single-channel spectrum. A two-channel audio interface does more: it carries a true I/Q pair, so the spectrum shows the full band above and below the tuned frequency, and it is the only kind that can play the receiver's audio through the iPhone speaker while you listen. The app tells you which class of device you have connected and what it allows, and an audio diagnostics panel shows exactly what iOS is doing with the signal if something does not sound right. Note: please make sure your receiver is compatible with the app's features and that you have the required accessories for optimal performance.

EMF Detector turns your iPhone's magnetometer into a live magnetic-field instrument, presented as a classic CRT vectorscope. The sensor is sampled at 100 Hz and monitored on two channels at once: steady field shifts from magnets, ferrous objects and motors, and AC ripple from live wiring. Field deviation is drawn as a phosphor beam with a persistence trail, and detected anomalies are marked on the scope and logged automatically with time and strength. VECTORSCOPE — the beam shows the direction and strength of the current disturbance; repeated activity builds a slowly fading heat picture of where it concentrates. ELITE 3D SCANNER — an alternative display in the style of the 1984 classic, showing the field's vertical component on a tilted scanner plane. BENCH-METER READOUTS — fourteen-segment displays for field strength, baseline, deviation and AC ripple, with a FIXED/AUTO baseline lock and one-tap re-baseline. APPLE WATCH — a companion app with its own sensor, alerts and a mini scope. PRO (one-time purchase): • REM-POD MODE — park the phone at a location and monitor it from your wrist: the watch mirrors the scope, meter and anomalies live, with an optional alarm on the parked phone. • WATCH REFERENCE MODE — use the watch as an ambient reference to distinguish local disturbances from room-wide changes. • Map of geotagged anomalies, CSV/GPX export, unlimited history and custom sensitivity. The instrument measures real magnetic fields: readings reflect physical sources such as wiring, appliances and magnetised objects. How you use it is up to you.