Introduction

HT699 is a simple FM Transmitter which using microphone to broadcast user's voice to any FM Radio.  The frequency band is selectable from 88MHZ - 108MHZ. 

Product Features

• Input Voltage: 9V-12VDC
• Frequency : 88-108MHZ 
• Used BA1404 IC
• Transmission can be listened to on any FM Radio.

Assembly Instructions

• Check off the components in the package against the component listing before assembly.
• Start with the smallest components working up to the taller components, soldering any interconnection wires last.
• Place and Solder the components into the board, make sure the components are in right position according to the overlay of PCB.

Test & Adjustment

• After assembled, please check & ensure the value & polarity for all components were inserted into PCB correctly, wrong polarity connection of capacitors can caused explosion of failure.
• Next, ensure all these leads are soldered, no solder bridges between adjacent pads and no dry joint.
• Once confirmed, connect the power source to the circuit board. 
• Use a ceramic screwdriver to adjust the variable coil (L1) to approximately mid-track position, and then adjust the variable capacitor C6 slowly to select the desired radio station while talking to the microphone.
• If the noise is still detected, increase or decrease the setting of variable coil (L1) to achieve the best performance.