The photo at upper left shows the first KWID shortwave curtain antenna under construction at Islais Creek in San Francisco in early 1942.   The other photos, taken from post-war publications, show the completed antenna array for KWID and KWIX at the end of the war.  The lattice towers were all constructed from wood. 

The two shortwave stations were already in the planning stages when the Japanese attacked Pearl Harbor in December of 1941.  A priority was then placed on the stations' construction, and KWID was on the air by May of 1942.   It's believed that the antenna was located on property to the immediate West of the KSFO transmitter building.  The view is probably to the Southwest, which would mean the hill in the background is the present location of McLaren Park.   (This part of San Francisco was still fairly undeveloped, and did not have the population density of today.)