Gary Albert, better known online as the HDMI Guy, is the editor of HDMI RF Modulator, a practical resource for people trying to make old-school video equipment work with modern TVs, displays, and home entertainment systems.
As a fan of gargantuan cabinet-style tube TVs, I’ve had to deal with more than my fair share of adaptors and modulators and converters (oh my!). That’s where I most often encounter the need to send picture and sound from an HDMI device like a 2000s+ gaming console to a television that only accepts an RF/coaxial signal, nine times out of ten the simplest solution is an HDMI-to-RF modulator. These devices convert a modern HDMI signal into a television channel that can travel over ordinary coaxial cable.
That makes them useful for connecting newer equipment to older TVs, sending one video source to several televisions, or distributing a signal through coaxial wiring that is already installed in a house, business, bar, hotel, or other building.
Start With an HDMI-to-RF Modulator
An HDMI-to-RF modulator takes the HDMI output from a device such as a streaming box, cable receiver, satellite box, Blu-ray player, computer, or security system and converts it into an RF television signal.
It’s looks like this, basically: HDMI source → HDMI cable → HDMI-to-RF modulator → coaxial cable → TV
Connect your source device to the modulator with an HDMI cable. Then run coaxial cable from the modulator’s RF output to the television’s antenna or cable input.
Depending on the modulator, you’ll select an output channel. You then tune the television to that channel to see the HDMI source.
Choose the Right Type of Modulator!
Not all HDMI-to-RF modulators do exactly the same thing.
Basic Analog HDMI to RF Modulators
Basic HDMI to RF modulator models like the Aoespy (for a very reasonable $45 here) convert HDMI to an analog RF channel. These can be useful with older (pre-digital) TVs, and/or when a tight budget is narrowing your options.
Digital HDMI to RF Modulators
If picture quality matters to you, and/or you’re distributing HDMI to multiple TVs, then a higher-quality HDMI to RF modulator digital is what you want. They wil cost you more (within the range of $500 for a decent model to $5,000 to the top of the line), but paying for digital modulation, MPEG encoding, much better picture quality, high RF output, channel agility, network configuration and equipment intended to operate as part of a real television distribution system.
Uncomplicated Mid-Range Models (Under $500)
More advanced HDMI to RF modulators create digital TV channels that modern televisions can receive through their coaxial tuners. If you’re distributing video to multiple TVs, a digital HDMI to RF modulator is the better choice. It can provide noticeably higher picture quality and is designed for modern digital television systems.
There are several in the lower price range that do a great job. My go-to is the Thor Petit (read my review of the Petit here). You can find it here for $469 (w/free shipping).
Before buying one, check which television standard the modulator supports and whether your TVs can tune that type of signal.
Why Not Just Use an Adapter?
HDMI and RF are fundamentally different types of signals, so this isn’t a situation where a simple passive cable will do the job.
An HDMI-to-coax cable by itself cannot normally turn an HDMI video signal into a TV channel. The signal has to be electronically converted and modulated. That’s why you need an actual powered converter or RF modulator.
Be cautious of inexpensive cables advertised as universal HDMI-to-coax solutions. A cable may physically connect two pieces of equipment, but that doesn’t mean it can perform the signal conversion required.
Distributing the Signal to Multiple TVs
One major advantage of RF is that coaxial signals can be distributed easily.
After the HDMI signal has been converted to RF, you can often use coaxial splitters to send it to multiple televisions. This can be particularly convenient in buildings that already have coax running to several rooms.
For longer cable runs or larger installations, you may also need an RF amplifier to compensate for signal loss. Every splitter reduces signal strength to some degree, so a system feeding ten TVs requires more planning than one feeding two.
What About Picture Quality?
Converting HDMI to RF can involve some compromise, particularly when you’re converting high-definition HDMI into an older analog television format.
If picture quality is important, choose a digital HDMI-to-RF modulator capable of handling the resolution you need. For simply getting a streaming device or other HDMI source onto an old television, an inexpensive analog modulator may be perfectly adequate.
The best solution ultimately depends on what you’re trying to accomplish. For one old TV, a basic HDMI-to-RF converter may be all you need. For distributing HDMI throughout a building over existing coax, a proper digital RF modulator is usually the cleaner, more reliable approach.
Yes—sometimes, but it depends on whether the newer TV still includes an analog NTSC tuner.
The easiest way is to look up your TV’s model number and check its tuner specs. Looking for “ATSC/NTSC,” “NTSC/ATSC/QAM,” or “Analog & Digital Tuner.” Don’t assume it can receive an analog RF modulator without any of the above.
It depends entirely on what you’re trying to accomplish. For a handy side-by-side use comparison, check out our Analog vs Digital HDMI RF Modulator guide.