A modular family of encrypted audio surveillance systems and supporting hardware. Each product is available in several variants to suit the operational environment, concealment requirement and counter-surveillance threat level. Full specifications are released on enquiry.
Brief descriptions are provided below. Detailed datasheets, frequency plans, variant options and pricing are supplied to qualified buyers following an enquiry.
A compact, long-range encrypted audio transmitter providing a continuous live voice link. Digital frequency-hopping carrier with AES-128 encryption and voice-activated transmission for extended covert operation. The core product of the K9 audio range.
Records high-fidelity audio to encrypted on-board storage and transmits it later as a single compressed, frequency-hopping burst. Reduces the on-air footprint to seconds — engineered for environments where periodic counter-surveillance sweeps are expected.
Transmits audio over a building's existing mains wiring rather than through the air. Because it does not radiate, it is invisible to conventional RF detectors and air-spectrum surveys. Supplied with a matched mains- or battery-powered receiver.
A portable receive station that decodes the K9 encrypted audio link and monitors multiple transmitters simultaneously. Provides clear monitored audio with time-stamped recording output for the listening post.
Bespoke concealment of K9 audio modules within everyday objects, custom frequency plans, and white-label manufacture for established professional surveillance distributors. Developed under confidentiality to agreed specifications.
Most products are offered in standard, extended-battery and body-worn configurations, with a choice of frequency plans and concealment options. Variant availability, full technical specifications and pricing are released to qualified buyers — please make an enquiry with your organisation and intended professional application.
Covert audio devices are not interchangeable. The right choice depends on the operational environment, how the device will be concealed, and — above all — the counter-surveillance threat the operation faces. The sections below explain the main categories so buyers can frame an enquiry around their actual requirement.
Continuous encrypted transmitters. A live audio link is the most flexible option: audio is monitored in real time at the listening post. The K9 Sentinel Live is built for this role, using a frequency-hopping encrypted carrier so the link is far harder to detect and impossible to decode without the key. Voice-activated operation extends battery life and reduces the on-air footprint by transmitting only when there is something to hear. This category suits situations where real-time intelligence matters and the counter-surveillance risk is moderate.
Store-and-forward burst transmitters. Where an operation faces a sophisticated adversary who conducts periodic spectrum sweeps, a continuous transmitter — however well designed — eventually presents an opportunity to be found. A burst device, such as the K9 Phantom Burst, sidesteps this by recording audio to encrypted on-board storage and transmitting it later as a single compressed, frequency- hopping burst. The device is silent for the overwhelming majority of the day, reducing the detectable window to seconds. The trade-off is that audio is reviewed after the fact rather than monitored live.
Mains carrier-current devices. Some environments make any radio emission a liability. A carrier-current device, such as the K9 Mainline, transmits audio along a building's existing mains wiring rather than through the air. Because it does not radiate, it is invisible to conventional RF detectors and to air-spectrum sweeps entirely — it sits in a different detection category. It draws power from the mains it uses as its transmission medium, and is paired with a matched receiver on the same electrical circuit.
Receivers and listening posts. Any transmitter is only half of a system. The K9 Vantage receiver decodes the encrypted audio link, monitors multiple transmitters at once, and provides clear, time-stamped recorded output for the listening post — important where recordings may need to support a later evidential or investigative process.
Bespoke and OEM development. Where a standard product does not fit the requirement, K9 undertakes custom concealment of audio modules within everyday objects, develops custom frequency plans, and manufactures white-label equipment for established professional distributors. This work is carried out under confidentiality to an agreed specification.
K9 Electronics supplies covert audio equipment to a defined professional and agency customer base. Understanding the process before you enquire helps us respond quickly.
Detailed specifications, frequency plans and pricing are not published on this website. They are released to qualified buyers following an enquiry, once the intended professional application is understood. This is deliberate: it allows equipment detail to be matched to a genuine requirement and supports our end-user policy.
Enquiries are welcome from law enforcement and investigative units, government and defence agencies, licensed professional investigators, and established surveillance equipment distributors interested in wholesale or OEM supply. International enquiries are handled in accordance with UK export-control requirements. To begin, please contact us with your organisation, your country, and a brief description of the intended professional application.