kurtmark HDMI to RF Modulator CH3/CH4 1080P

This compact, plug-and-play device sends HDMI video and audio to older televisions or RF-input equipment without drivers or complicated setup. It includes a 1.2m HDMI cable and power adapter so you can connect streaming sticks, game consoles, set-top boxes, or media players directly to a coax input. The unit supports common resolutions up to 1080P and uses PLL control to keep the VHF frequency stable for consistent viewing on NTSC-based TVs.

How do I hook this up to my TV or console?

Setup is straightforward: connect your HDMI source to the modulator, attach the coaxial cable from the unit to your TV's antenna/RF input, select channel 3 or 4 on the modulator, and power the device. No software or driver installation is needed.

• Connect included 1.2m HDMI cable to source and modulator HDMI input.
• Use a coax cable from modulator RF output to TV antenna/RF input.
• Power the modulator with supplied adapter and choose CH3 or CH4 output.
• Set your TV to the selected channel to view the converted signal.

Which devices and resolutions are supported?

The modulator accepts HDMI 1.4 sources and honors HDCP 1.4, so it works with many streaming sticks, consoles, DVD players, PCs, and DVRs. It accepts a range of input resolutions and outputs a stable NTSC RF signal for legacy displays.

• Compatible with Fire TV, Roku, Apple TV, PS5, Xbox, Nintendo Switch, PCs, and DVD/Blu-ray players.
• Accepts 1080P, 1080i, 720P, 576P, and 480P input resolutions.
• Outputs NTSC RF on CH3 (61.25MHz) or CH4 (67.25MHz).
• Supports HDMI 1.4 and HDCP 1.4 protected sources.

What kind of picture and signal stability can I expect?

The device uses PLL (phase-locked loop) control to maintain a steady VHF frequency and deliver consistent RF output strength. While converting a digital HDMI feed to analog RF has inherent limitations, the modulator provides reliable performance for typical home use.

• Designed for 1080P conversion with PLL frequency stabilization.
• Standard NTSC audio subcarrier (M: 4.5 MHz) for compatible sound playback.
• RF output level around 80 ± 5 dBµV for typical antenna inputs.
• Best results when used with short, quality coax runs and proper TV tuning.

Are there any important limitations I should know?

This product converts HDMI to RF/Coax only — it does not perform RF-to-HDMI conversion. Also, output is NTSC analog RF on CH3/CH4, so image fidelity is constrained by analog broadcast format and your TV's RF tuner capabilities.

• Not reversible: does not convert RF/Coax to HDMI.
• Output limited to NTSC analog, not digital over-the-air formats.
• Video quality is subject to analog RF resolution limits compared with direct HDMI.
• Use with devices that enforce HDCP 1.4 for best compatibility.

Who this is for: The kurtmark HDMI to RF Modulator is designed for anyone needing to feed modern HDMI sources into older TVs, hotel-room displays, educational equipment, or RF-only monitors. It’s a practical choice for retrofitting legacy installations, sharing a single HDMI device across multiple RF-only TVs, or connecting consoles and media sticks to coax inputs without replacing existing wiring. If you require full digital output quality, an HDMI-equipped display is recommended; if you need a simple, reliable analog RF solution, this unit offers an all-in-one kit with cable and power supply included.