Tagged: analogue tv

Watching the Analog TV Shutdown in Brazil

Over the last few years Brazil has been moving over to digital TV, and has planned to shut down the old analogue TV signals. Vinicius Lenci (PU2VLW) was watching with his SDR during the analog shutdown that occurred in Pedreira-SP on the 17th of January 2018 (note that the post is in Portuguese but Google Translate can be used). The video on his post captures the end of an era by eerily showing the analog TV audio signal suddenly cutting off and turning to noise. In another video where he was monitoring 16 analog channels with an analog TV receiver shows the channels slowly switching off one by one within a few minutes.

Shortly after the analog TV signals were shutdown, Vinicius notes that a new digital TV signal under test at 571 MHz appeared in place of one of the old analogue signals. Also he notes that the now empty 750 MHz band will eventually be replaced by mobile LTE technology.

Capturing the Analogue TV shutdown in Pedreira, Brazil.

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:)