Technical Surveillance Countermeasures · Reference

TSCM Spectrum Atlas

Everything you can expect to see between 0 and 43 GHz on a spectrum analyzer: what it is, where it lives, and what it means during a sweep. The core 0–12 GHz covers a normal sweep; 12–43 GHz is the extended range for the wideband analyzer (10 kHz–43 GHz). Built for recognising legitimate emitters quickly so the odd one out stands out.

Where covert devices tend to hide

Click a card to jump to that range

Spectrum map

Drag on the map to select a range · click a bar to jump to its entry
Each bar is one entry, colored by category. Dimmed bars are filtered out. The dashed line marks 12 GHz; to its right is the extended range.

Sweep priority

Hot Typical hiding place, or the abusable band. Identify every emission.
Watch Legitimate use, but a plausible carrier for a rogue device.
Baseline Known service. Recognise it, log it, rule it out.

Reading the analyzer

  • Step in 10–20 dB of attenuation. Real signals drop dB-for-dB; overload spurs and images drop faster.
  • Strong broadcast/radar can overload the front end. Use a preselector or filter before trusting the trace.
  • Pulsed radars and TDMA (GSM 217 Hz, DECT 100 Hz) need max-hold / peak detect and a demod check.
  • Wideband signals (UWB, spread spectrum) hide below the floor; widen RBW or use a noise-floor rise as a clue.
  • Always compare against a baseline taken with suspect equipment cycled off.
  • Above ~18 GHz: emissions are highly directional and cable loss is large. Use a horn antenna, short low-loss cable, and check harmonic-mixer image responses before believing a line.

Scope & caveats

Allocations are shown for ITU Region 1 / CEPT / Denmark. Sub-GHz SRD rules follow ERC Rec 70-03; mobile bands are the common European plan. Operator use varies (2G/3G are being sunset), and national plans change.

Non-EU entries (US 902–928, 315 MHz, DECT 6.0, etc.) are included because imported gadgets turn up in EU rooms. Verify against the current Danish frequency plan (Energistyrelsen) before quoting a client.

Beyond the 43 GHz analyzer: 57–71 GHz (Wi-Fi 60 GHz / WiGig), 71–86 GHz (E-band links) and 76–81 GHz (car radar) are not covered here.