Live spectrum scanning
Sweep 174–1200 MHz with your RTL-SDR — the full range used by wireless mics and IEM systems. Adjustable bandwidth, step size, gain, PPM correction and scan cadence.
Free channels
14 clean
RF spectrum coordination · RTL-SDR
Find clean frequencies before the downbeat.
Spektra turns an RTL-SDR dongle into a live spectrum scanner for your show — scan 174–1200 MHz with adjustable bandwidth, spot interference, and place every wireless mic and in-ear monitor on open air before you reach soundcheck.
Works offline at the venue
7 languages · light & dark
8 regulator regions
Occupied ranges
5 in use
Tightest margin
0.42 MHz
Signal level
Free
Occupied
Noise threshold
Live preview — synthetic data
174–1200
MHz scanning range
26
Built-in equipment presets
8
Regulator region overlays
7
Interface languages
Everything for coordination
One tool from scan to soundcheck
Spektra 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.
Automatic free-channel finder
A tunable noise threshold separates occupied broadcast and transmitters from open air — and lists every usable gap, widest first.
26 devices, any brand
Register your mics and IEMs from 26 built-in equipment presets — not locked to one manufacturer. Shure, Sennheiser, Lectrosonics, Wisycom, Sony and more, each with live status and margin.
Green / amber / red status
Every channel, range and device reads at a glance — clean, caution, or occupied — so problems jump out before they hit the stage.
Regulatory & IM awareness
Overlay each region's protected and cellular bands, and flag 3rd-order intermodulation products between your own transmitters.
Snapshots & export
Save before/after sweeps and overlay them to compare. Export clean channels to CSV or JSON, or hand off to your coordination workflow.
Up and running in minutes
How Spektra works
No rack of gear, no lab analyzer. A dongle, the backend, and your browser.
1
Plug in & launch
Connect any RTL-SDR dongle and start the included scanner.py backend. Spektra opens right in your browser.
2
Scan the band
Pick a band preset or set your own range, hit Start, and watch the spectrum fill in with free channels marked automatically.
3
Coordinate & go
Drop your gear onto the channel plan, confirm every device reads green, and export the numbers 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
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 Best value |
Pro coordination suite | Lab spectrum analyzer |
|---|---|---|---|
| Typical cost | €49 + €50 dongle | €1,000–4,000 | €2,000–10,000+ |
| Live RF scanning | ✓ | ✓ | ✓ |
| Automatic free-channel detection | ✓ | ✓ | — |
| Equipment channel plan & status | ✓ | ✓ | — |
| Intermodulation awareness | ✓ | ✓ | — |
| Multi-region regulatory overlays | ✓ | ✓ | — |
| Runs on a low-cost USB dongle | ✓ | — | — |
| Pocket-sized & portable | ✓ | Laptop + receiver | Bench unit |
What you need
Minimal kit. Maximum coverage.
RTL-SDR dongle
Any RTL2832U-based USB receiver (around €50). Widely available, and the only hardware you need.
scanner.py backend
Included Python service drives the dongle and streams sweeps to the app. Runs on Windows, macOS and Linux.
Any modern browser
The interface runs locally in Chrome, Edge, Firefox or Safari. No cloud account, no connection required.
One-time license
Buy Spektra once on Gumroad for €49, download instantly, and get updates for the version you own. No subscription.
Questions, answered
Frequently asked
What hardware do I need to run Spektra?
Any RTL-SDR USB dongle (RTL2832U based) and a computer running the included scanner.py backend. Spektra runs in your browser and connects to the local scanner — no internet required at the venue.
Which bands and regions does it cover?
Spektra scans 174–1200 MHz by default with adjustable bandwidth — the full range used by wireless mics and IEM systems. It includes region overlays for DE, UK, EU, FR, US, JP, AU and CA, plus 26 built-in equipment presets spanning Shure, Sennheiser, Lectrosonics, Wisycom, Sony and more.
Does it replace professional coordination software?
Spektra gives you the essentials — live scanning, free-channel detection, a channel plan with per-device status, intermodulation awareness and export — at a fraction of the cost of pro suites and lab analyzers, on a dongle that costs around €50.
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.
Can I use it without internet?
Yes. Spektra is a local application that talks to your RTL-SDR over USB. Once installed it runs fully offline — 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.
€49 one-time license · instant download · lifetime updates for your version
