Chicago's Willis Tower skyscraper goes digital

An engineer unscrews a TV antenna on top of the Willis Tower.

Please turn on JavaScript. Media requires JavaScript to play.

9 July 2012 Last updated at 12:51 ET Help

An analogue TV antenna which has sat on top of Chicago's Willis Tower since 1982 has been removed by a helicopter.

The redundant aerial is being replaced with a new high-powered digital transmitter.

Iain Smith reports.

Most watched/listened

US & Canada

World

Business

Science & Technology

Entertainment

UK

BBC links

- Parental Guidance
- Contact Us

BBC © 2013 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.