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  • Regular price $180.00
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The CTX1 is a customizable version of our V1TX Audio Surveillance Transmitter.

Measuring only 32mm x 28mm with a thickness of .8mm. There is no mounted battery compartment, the CTX1 comes lightly potted, which opens options for custom mounting or encasing to meet your specific needs. 

  • This Transmitter allows you to attach any power/battery option suited for your needs (≤ 3.7 Volts). The CTX1 has +/- solderable power/battery input terminals for you to attach custom power supply packs, enabling you to dramatically extend your transmitter's surveillance operation time using any Li-Ion power option or any custom battery pack. If you want us to attach a button cell battery holder for a CR2032 battery (CR2032 will provide 24-30 hours of audio surveillance) please let us know in your order notes.
  • No switches or indicator lights.

This is a permanent, always-on "hot-microphone", once the battery is inserted the CTX1 will begin live transmission of ambient and surrounding audio without interruption on the Ultra High-Frequency band. The CTX1 will broadcast audio over a distance of 500 metres in a cluttered urban environment, up to 1 kilometre with LOS, through concrete, drywall, and thick bush to any UHF receiver, it operates on any battery or power source pushing 3V to a maximum of 4.7V.

Use this transmitter to remotely listen to an area of interest that requires discreet acoustic monitoring. We recommend any handheld UHF receiver capable of tuning into the 400MHz-434MHz range, this is a standard range in most UHF receivers. Our recommended handheld receiver is the AnyTone AT-318UV. Your CTX1 will arrive with its specific Tx/Rx frequency noted on its back.

Power Supply Options

1x CR2032 (3v) : 24 Hours Of Continuous Operation.

1x 2600 mAh 18650 (3v) : 260 Hours Of Continuous Operation.

1x 3600 mAh 18650 (3v) : 360 Hours Of Continuous Operation.

Dimensions 15mm x 28mm x .8mm

100Hz ~ 20kHz Panasonic: Analog Microphone Electret Condenser. Directional Characteristic: Omni-Directional
Sensitivity: -7.0 ±4 (0 dB = fs/Pa@1kHz).
Signal to Noise Ratio: 78 dB Typ. at 1kHz.
Max Input Sound Level: 101 dB SPL Typ.

Weight Without Battery: 8g
Output (RF) power  14mW
Antenna 60mm OR 110mm: .5-.8mm NiTinol.
Frequency Range

136-174MHz/434MHz-436 MHz, 2.5 kHz step.

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


TINYTX's transmitters are easily paired with any compact hand-held transceiver. Any Two-Way UHF Radio will work, but we recommend the BaoFeng UV-5R from FengBros. Fengbros has been our trusted supplier for the last year, they offer certified Baofeng radios at the most competitive price.

In order to maintain its longevity, the CTX1 is potted with a compound or wrapped in heat-shrink which seals all onboard components, only the microphone and the battery terminals are accessible and made visible.

HAVE A NON-TRADITIONAL AUDIO SURVEILLANCE APPLICATION? 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.

 (PCB REV 2.0)