Tagged: NTSC

Broadcasting Analgoue NTSC TV with a $7 ESP8266

The ESP8266 is a $7 WiFi module that can be used to give any microcontroller access to a WiFi network. It is designed for creating Internet of Things (IoT) devices and has various features such as it’s ability to host it’s own web applications. The ESP8266 also has a I2S output with DMA support. By hooking up this I2S output pin to a short wire, YouTuber CNLohr has demonstrated that he is able to use the ESP to broadcast full color NTSC TV.  This works in a similar way to how PiTX works, by using the pin to modulate a radio signal. CNLohrs code note only broadcasts color NTSC, but also provides a full web interface for controlling it.

In the first video CNLohr shows off his initial work at getting the NTSC output working and in the second video he shows color working. Later in the second video he also uses an RTL-SDR to check on the NTSC spectrum that is being output.

Broadcasting Analog TV on an ESP8266!
Broadcasting COLOR Channel 3 on an ESP

Receiving NTSC Analogue TV with GNU Radio and an RTL-SDR

Over on GitHub user kik has uploaded a tutorial and code showing how to decode NTSC analogue TV in GNU Radio and an RTL-SDR. The tutorial is in Japanese, but Google translate should be good enough to understand the text. Kik shows us what GNU radio blocks to use and provides the python code needed to display the images on a simulated scope.

If you just want to receive analogue TV signals, try TVSharp.

gnuradiontsc
GNU Radio Decoding NTSC and showing images on a Scope

TVSharp Updated to Version 1.2

The PAL/NTSC analogue TV viewer TVSharp has recently been updated to version 1.2. This new version features an updated GUI as well as automatic frequency correction and automatic position correction. This may correct some of the scrolling and slanting problems seen in previous versions.

The latest TVSharp can be downloaded from here.

Word of warning: Chrome recognizes the download as malicious, however I have downloaded the file using FireFox and scanned it with Microsoft Security Essentials which found it to be clean.

TVSharp v1.2
TVSharp v1.2

Analogue TV with RTL-SDR

A user on the SDR# Google Groups forum has posted a program based on ADSB# called TVSharp, which can be used to watch analogue PAL and NTSC TV using the rtl-sdr dongle. Download TVSharp directly here (Mirror 1) (Old Version Mirror 2 (with source)).

The rtl-sdr as a software defined radio actually does not have enough bandwidth to receive a PAL or NTSC signal properly. PAL and NTSC signals require more than double the 2MHz typical bandwidth of the rtl-sdr. But, a decent black and white signal can still be obtained by using some of the luminance part of the signal.  As only part of the signal is sampled, resolution will be lost. Also, as sound is broadcast on a separate frequency, a second rtl-sdr dongle will be required to receive the matching audio.

On YouTube, users Superphish and ek6rc have posted videos showing TVSharp in action.

Analogue PAL TV with RTL SDR (RTL2832) and TVSharp
TVSharp R820T SDR sound via Yaesu VX-7:)