How to Use: Step 1: Connect the USB output power adapter Step 2: Set the channel switch to CH3 or CH4, and the modulator switch to ON. (Set to OFF, RF part does not work) Step 3: Connect the RF input and output Step 4: Power on the HD Multimedia Interface device and connect the  HD Multimedia Interface input signal Step 5: Turn on the TV to CH3 or CH4 Please strictly follow the above steps! Specification: Item Type: Modulator Material: ABS Model: HDM66 TV Standard Format: PAL/NTSC Frequency Range: PAL: 55.25mhz / 62.25mhz NTSC: 61.25MHz / 67.25MHz Output Level: 80±5dBuV Sound System: M=4.5MHz, B=5.5MHz Input Port: HD Multimedia Interface Output Port: RCA Female Header Rf Input: F Female Rf Output: F Female Input Resolution: 1080P / 1080I / 720P / 576P / 576I / 480p HD Multimedia Interface Version: 1.3 HDCP Version: 1.3 Input Voltage/Current: DC 5V/500mA (min) Operating Temperature: 0℃~+40℃ Package List: 1 x Modulator 1 x Power Cord 

• 【HDMI RF Modulator Plug and Play】The HDM66 HDMI modulator support NTSC and PAL TV format output, Frequency Range : PAL：55.25MHz/62.25MHz；NTSC：61.25MHz/67.25MHz, no driver installation, portable, flexible, plug and play.
• 【Applicable】: The HDM66 HDMI modulator has fine workmanship, quality assurance, suitable for your local CATV system. Support HDMI 1.3 and HDCP 1.3
• 【Parameters】: PLL control of VHF operating frequency, HDMI input, A/V output(RCA female), RF output.
• 【Safe and Reliable】: The HDMI modulator is made of high quality ABS material, durable, long service life. The CATV modulator has professional manufacturing, stable performance, high reliability.
• 【Simple Operation】: Step 1: Connect the USB output power adapter; Step 2: Set the channel switch to CH3 or CH4, and the modulator switch to ON. (Set to OFF, RF part does not work); Step 3: Connect the RF input and output; Step 4: Power on the HD Multimedia Interface device and connect the HDMI input signal; Step 5: Turn on the TV to CH3 or CH4