Universal RF Modulator Lets You Connect a Digital STB to a TV Without Composite Video Inputs

Many of us have old Analogue TV’s that are in tip-top shape and have a superb picture. They kept us entertained when we grew up and are now like a member of the family, so we can’t imagine parting with them.

Some of our beloved TVs can receive Digital TV with the aid of a Set Top Box (STB). You simply connect the TV antenna to the back of the STB, and then you connect the set top box to your TV using the composite video and audio inputs.

Unfortunately, some of our old TVs don’t have composite video inputs, which would usually prevent us from connecting a Digital Set Top box (STB) or DVD player. An RF modulator lets you take the composite video and audio output from your STB and convert it into a broadcast signal that can be tuned in on your analogue TV like a normal TV station.

Why I Bought the Universal RF Modulator

This was the case with my old Toshiba Blackstripe 49cm TV, purchased around 1987. It has 12 silver rectangular push-buttons for the channels and a round black push-button that serves as both the on-off switch and the volume control. To be able to watch Digital TV broadcasts, I purchased a Shintaro SH-SDST01 Set Top Box with USB recording functionality.

I needed an RF modulator and I found this model, which had a number of features that made it desirable:

Universal RF Modulator Features

Adjustable UHF TV Channels

This model lets you adjust the TV channel to any channel between UHF 21 and 69 using two push-buttons, so you can avoid channels that have interference. It displays the selected channel on two 7-segment LED displays located on the top.

Inferior models often have a single fixed channel selection.

Dual SCART sockets – SCART In and SCART out (Loop Through, Input Video) as well as Composite Video in

All European-made TVs and VCRs since 1980 have SCART connectors, which carry most TV signals in one convenient bundle. This was brilliant forward thinking by the French, who developed the standard in the late 70’s.

If your Set Top Box has an S-Video output, you can connect it to the RF modulator using an S-Video to SCART cable to get better image quality than with composite video.

PLL Control Circuitry

This means the electronic circuit inside the Universal RF modulator uses a Phased-Lock Loop to generate the broadcast signal, it will maintain a stable frequency that won’t drift.

Supports Stereo Audio

The very cheapest ones might only support mono audio.

Buying an RF Modulator

This model is being sold on eBay Australia as “Universal RF Modulator” and it is also available at Dick Smith Electronics. Naturally, this model only supports the PAL TV standard, which is/was used here and in most European & Asian countries. RF modulators sold in the USA will of course support NTSC.

If this model is not available in your area, just make sure that you get an RF modulator with an adjustable TV channel and stereo, if your TV supports it.

Other Uses for the RF Modulator

Connecting a DVD Player or Games Console to an Old TV

This works the same way as with the Set Top Box.

Connecting a Computer to An Old TV

If you combine the RF modulator with a VGA to Composite video converter, this will allow you to use your old TV with a computer. This might be useful for watching movies with guests, or if you want to use your old TV as a second (or third) monitor. The image will not be super-sharp, but you should be able to get an effective resolution of 640×480 or 800×600.