Sheep Guts: The Frequency is 37.5 KHz which is on the Low Frequency LF band 30khz -300khz
Sheep Guts, that in the RADIO SPECTRUM. A ULB's 37.5 KHz is in the AUDIO SPECTRUM. Basically, it's high AUDIO frequency buzzer. Submarines that can tow a mile long antenna and supply thousands of watts of power can use the low frequency radio waves to communicate under water, but the antenna and power requirement isn't practical for an Underwater Locator Beacon in a sunken aircraft.