Hello Roy,
According to David Harvey's book on Birmingham Trolleybuses, there were only two routes in Birmingham. One from Old Square to Nechells via Aston Street, Bloomsbury Street, Nechells park Road. The second route was from Albert Street, Digbeth, Station Street, Deritend, Coventry Road to Sheldon and Lode Lane. The trolleybuses were taken off in 1951.
My grandfather was an inspector at Moseley Road tram depot and we used the Moseley Road trams and then buses from King's Heath to town. I can only remember seeing the trolleybuses in Albert Street and down Digbeth.
Brian