The KPO antenna was a "T" type, four wires spread six feet apart, and 114 ft. in length. It was supported by two 125 ft. towers which had been erected by the Pacific Coast Steel Co. on the roof of the Hale Brothers' Department Store on Market Street. This gave the antenna a total height over the street of 220 ft. The studio and transmitter were located on the sixth floor of the store building. 

When KPO increased its power to 5,000 watts, larger 250 ft. towers were built, as shown in the 1929 lower photo.  One of the towers was moved to the Hale Bros. annex building in order to direct the signal in a North-South direction.