Los Angeles C.D. siren test (Audio Only)

This is the only known-to-man recording of a Civil Defense siren test in the city of Los Angeles, California. Around 200 sirens were placed around the city during the cold war, and were tested on the last Friday of each month at 10:00 AM sharp. The siren heard is believed to be an Federal Sign & Signal SD-10 model, since it does not seem to rotate, and has the same port ratio (9/12) as the Federal Sign & Signal 500SH-TT, another widely used siren in LA's system. On a side note, this recording is not mine. I found it on a website that had sound effects for film & project usage. I found this very interesting, so I decided to post it up.