RF spectrum scanning & coordination · SDR hardware from ~€40

Find clean frequencies before the downbeat.

Spektra RF sweeps the UHF wireless-mic band in seconds on an SDR from around €40 — live spectrum with waterfall, clear free/occupied verdicts, and a Frequency Advisor that turns the measured gaps into an intermod-safe, printable coordination plan in one click.

Get Spektra RF — one-time license Try the live demo Open on the platform

Works offline at the venue Double-click app · no Python, no drivers Interactive demo · free account, no dongle 7 languages · 8 regulator regions

spektra rf · live · 470–700 MHz

SCANNING

Free channels

14 clean

Occupied ranges

5 in use

Tightest margin

0.42 MHz

Signal level

Free

Occupied

Noise threshold

Live preview — synthetic data

128

Coordinated channels max

27+

Equipment device families

Analyzer families auto-detected

Interface languages

Everything for coordination

One tool from scan to soundcheck

Spektra RF covers the whole pre-show RF workflow — sweep the band, read what's free, lay out your channel plan, and hand off clean numbers to the stage.

Live spectrum + dual waterfall

Full 470–700 MHz UHF sweep in a few seconds, ~1-second cold start, band presets for DECT and 2.4 GHz — hardware permitting up to 6 GHz. A live waterfall on IQ-capable devices plus a timestamped sweep-history strip on every analyzer.

Frequency Advisor

4–128 coordinated, intermod-safe suggestions placed inside the actually measured free windows — full 2-tone/3-tone IM3 checking, Robust and High-density profiles, and deterministic results: a reprinted plan always matches the printed one.

8 analyzer families, one picker

RTL-SDR (from ~€40), tinySA & tinySA Ultra, RF Explorer, HackRF One, Airspy and SDRplay — auto-detected on plug-in. No hardware yet? Demo mode generates a synthetic spectrum for training.

Smart 3-state occupancy

Not a dumb threshold: Spektra RF distinguishes your own carriers (green) from contention on your channel (amber) and unknown interference (red) — with a suggest-threshold helper for the noise floor.

27+ device families & regulation

Shure, Sennheiser, Lectrosonics, Sony and budget channel-wheel gear — group/channel picks resolve to exact MHz. Regulation overlays for 8 regions tint TV whitespace and give each device a license verdict.

Listen, snapshot & hand off

FM-demodulate and listen to any parked frequency with squelch and level meter. Save and compare sweeps, export scans as CSV/JSON — and hand guest crews the Advisor's coordination CSV or printable A4 PDF with spectrum snapshot.

Straight off the screen

The spectrum view, reading a band

The same view you'll run at the venue — captured here in the free browser demo on a synthetic sweep: 10 free channels, 9 occupied ranges, the noise threshold and the channel plan overlaid.

Spektra RF's spectrum view in the browser demo: a 470–700 MHz sweep with labeled carriers like Vocal RX 1 and IEM Band R, occupied ranges shaded red, free ranges green, the dashed noise threshold, and counters reading 10 free channels and 9 occupied ranges. — Free in green, occupied in red, tightest margin in MHz — drive this exact view yourself in the live demo; the desktop app draws the same picture from real RF.

Up and running in minutes

How Spektra RF works

No rack of gear, no lab analyzer, no install marathon. A dongle and a double-click.

Plug in & launch

Connect any of 8 supported analyzers — Spektra RF auto-detects it and cold-starts in about a second. Everything is bundled in one double-click app: no Python, no drivers.

Scan the band

Sweep the UHF band in seconds, watch the waterfall, and read the 3-state verdicts: your carriers green, contention amber, intruders red — every usable gap listed.

Coordinate & go

One click on the Frequency Advisor places 4–128 intermod-safe frequencies inside the measured gaps — print the A4 coordination sheet and hand it to the stage.

Built for any crew

Speaks your language. Suits your venue.

The interface ships in seven languages and switches instantly — no reload. Dark mode for the FOH position, light mode for daylight load-in, with a tunable accent so it fits your rig.

EnglishDeutschFrançaisEspañolItalianoNederlandsPortuguês

Dark

Light

Why Spektra RF

Pro-level coordination, without the pro-level invoice

Get the essentials that matter on show day for a fraction of the cost of dedicated suites and lab hardware.

Capability	Spektra RF Best value	Pro coordination suite	Lab spectrum analyzer
Typical cost	€49 + €40 dongle	€1,000–4,000	€2,000–10,000+
Live RF scanning + waterfall	✓	✓	✓
Automatic free-channel detection	✓	✓	—
Intermod-safe coordination (IM3), up to 128 ch	✓	✓	—
Own-carrier vs. interference detection	✓	Partial	—
Printable coordination sheet (PDF)	✓	✓	—
Multi-region regulatory overlays	✓	✓	—
On-frequency audio monitoring	✓	—	Some
Runs on a low-cost USB dongle	✓	—	—
Pocket-sized & portable	✓	Laptop + receiver	Bench unit

What you need

Minimal kit. Maximum coverage.

An SDR or analyzer

From a ~€40 RTL-SDR to tinySA, RF Explorer, HackRF, Airspy or SDRplay — 8 families, auto-detected. Or start in demo mode with no hardware at all.

A Mac or Windows PC, one double-click

Ships as a compact desktop app for macOS (Apple Silicon & Intel) and Windows with everything bundled — no Python, no Homebrew, no driver installs.

Spektra RF is not notarised by Apple yet. On first launch, macOS will block it once; the Getting Started guide shows the one-line Terminal command that clears this.

Nothing else

100% local and private: binds to localhost only, no telemetry, no account, no cloud. Works fully offline at the venue.

One-time license

Buy Spektra RF once on Gumroad for €49, download instantly, and get updates for the version you own. No subscription.

Licences & source

One app, two licences. Spektra RF's desktop app — the shell you install and the interface you see — is proprietary software covered by the Spektra EULA. The scanning engine inside it is free software under the GNU GPL v3 (or later), and its complete source code is published here with every release, so you can read it, build it and change it.

End-User License Agreement (EULA)the terms for the app.
Third-party noticesevery open-source component we ship and the GPL written offer.
Licence mapexactly which files are proprietary and which are GPL.
GNU GPL v3the full licence text.

Engine source code current release 3.19.0

Version	Download	SHA-256
3.19.0	spektra-engine-src-3.19.0.zip (180 KB)	`cdbb16a0d7db9af5b1f257f3e2d5ab43afe55df28e8a5c413700ec53b21be224`

The archive corresponds to the engine bundled in the 3.19.0 installers. Source for the native libraries listed in the third-party notices (librtlsdr, libusb and friends) is available from their upstream projects or on request from support@squaresmile.de.

Questions about licensing: support@squaresmile.de

Questions, answered

Frequently asked

What hardware do I need to run Spektra RF?

Any of 8 supported analyzer families, auto-detected on plug-in: RTL-SDR Blog V3 (the ~€40 reference device) and generic RTL2832U dongles, tinySA and tinySA Ultra, RF Explorer WSUB1G and 3G Combo, HackRF One, Airspy, and SDRplay RSP models. No hardware yet? A built-in demo mode generates a synthetic spectrum so you can learn the app first.

Which bands and regions does it cover?

The default sweep covers the 470–700 MHz UHF wireless-mic band in a few seconds, with presets for DECT (1880–1900 MHz) and 2.4 GHz — and capable hardware can tune up to 6 GHz. Regulation overlays for 8 regions (DE, UK, EU/CEPT, US, FR, AU, JP, CA) tint TV whitespace and give each registered device a license verdict: license-free, registration required, or forbidden.

Does it replace professional coordination software?

For the pre-show workflow, it closes the whole loop: sweep the band, read what is genuinely free, and let the Frequency Advisor generate 4–128 intermod-checked frequencies inside the measured gaps — then print the plan as an A4 PDF. What it does not do is remote-control receivers the way manufacturer suites do for their own gear.

How do I buy and download it?

Purchase a one-time license through Gumroad. After checkout you get an instant download link plus future updates for that major version. Spektra RF ships for macOS (Apple Silicon & Intel) and Windows as a double-click app — no Python, no driver installs, everything bundled.

Can I use it without internet?

Yes. Spektra RF is 100% local: it talks to your analyzer over USB, binds to localhost only, and sends no telemetry. No account, no cloud — ideal for festival sites and venues with no connectivity.

What languages and themes are supported?

Seven interface languages — English, German, French, Spanish, Italian, Dutch and Portuguese — with light and dark themes and a tunable accent color.

Stop guessing. Start scanning.

Walk into your next show knowing exactly which frequencies are clean.

Get Spektra RF on Gumroad Try the live demo

€49 one-time license · instant download · updates for your major version · or try the interactive demo free (just an account, no dongle)

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