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  • Regular price $200.00
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The CTX2 is a slimmer rectangular variation of our V1TX Audio Surveillance Transmitter. Measuring a mere 25mm x 15mm with a thickness of 0.8mm, this transmitter offers a compact and discreet form factor. The CTX2 comes pre-mounted with a button cell battery holder designed for a CR2032 battery, which provides an impressive 25-30 hours of continuous audio surveillance. This transmitter is now available with a new extremely sensitive KNOWLES microphone, and a new high-powered crystal generating 20mW of RF power, ensuring superior frequency stability and delivering enhanced audio sensitivity. For custom power options to extend the operating time, please feel free to contact us for further assistance.

Designed for covert operations, the CTX2 features a minimalist design with no switches or indicator lights, ensuring discreet usage.

Once the battery is inserted, the CTX2 functions as a permanent, always-on "hot-microphone," immediately initiating live transmission of ambient and surrounding audio without interruption on the Ultra High-Frequency band. In a cluttered urban environment, the CTX2 broadcasts audio over a distance of 500-800 meters, with a maximum range of 1 kilometer in Line-of-Sight (LOS) conditions. It effectively transmits audio through obstacles such as concrete, drywall, and dense vegetation, offering versatility in various monitoring scenarios. The transmitter operates efficiently on a single button cell battery.

Use the CTX2 to remotely listen to areas of interest that require discreet acoustic monitoring. We recommend utilizing any handheld UHF receiver capable of tuning into the standard frequency range of 400MHz-434MHz, which is supported by most UHF receivers. For optimal performance, we suggest the Baofeng UV-5R or the AnyTone AT-318UV as our recommended handheld receivers. Rest assured, your CTX2 will arrive with its specific Tx/Rx frequency clearly noted on its back for easy configuration with your receiver.

Power Supply Options

1x CR2032 (3v) : 25-30 Hours Of Continuous Operation.

Dimensions 15mm x 28mm x .8mm

CUI: 100 Hz ~ 20 kHz Analog Microphone Electret Condenser Omnidirectional (-42dB ±3dB @ 94dB SPL)

KNOWLES BJ-21590: 300 Hz ~ 5 kHz Analog Microphone Magnetic Omnidirectional (-75.5dB ±3dB @ 74dB SPL)

Weight 8g
Output (RF) power  20mW
Antenna Alpha Wire 8 in. Micro Coaxial Cable 38 AWG 
Frequency Range

433MHz-436 MHz, 2.5 kHz step.

Effective Range 15m From Centre. 
Stability  Highly Stable. Crystal Referenced Phase-Locked Loop.
Crystal 00k/ASK Data Transmitter.

In order to maintain its longevity, the CTX2 is potted with a compound or wrapped in heat-shrink which seals all onboard components, only the microphone and the battery terminal are accessible and made visible.

We can design for your needs. TINYTX has designed and manufactured hidden and covertly disguised audio surveillance transmitters for several client projects and applications. Contact us for turnkey solutions.