702 ABC Sydney’s breakfast host Adam Spencer would not want to have a fear of heights.

This Friday he will broadcast from 5.30am to 7.45am from atop the Sydney Harbour Bridge.

He will have an eagle eye view over Sydney on the eve of the 75th anniversary of the bridge, which coincides with the ABC’s own 75th birthday celebrations.

Fortunately for him the weather forecast for Friday is favourable.

The bridge-top OB is the first in a series to mark the anniversary.

Ian ‘Macca’ McNamara will broadcast Australia All Over from 5.30am on Sunday from the courtyard at the Sydney Observatory on Observatory Hill and Simon Marnie will broadcast from 10am live from the midst of the Harbour Bridge Walk, as thousands of people make their way across the bridge.