[Allen]

"Multiple Frequency Technology       22 frequencies "   

"Detection Frequency       750 pulses per second, adjustable" (elimination adjustement ?)

I'm slightly perplexed .... please help !

[Paul van Heerden]

You got me *shrugs*. Sorry

[Barney]

Read the article http://www.deeptech-bg.com/Understanding_The_PI_Detector.htm - a link added by Danie earlier.  The delay affects the amount of pulses per second - an increase of the delay causes less pulses per second (frequency of pulse) and vice verse which in turn has a direct influence on your detection performance - the article explains it quite nicely.  The frequency of pulse is different from the frequency on which the detector operates - it works very similar to an aircraft radar.  A radar detects by transmitting high energy pulses at a certain interval and then detects the reflected signal from a target, but the frequency on which the radar transmits is fixed for example 3 GHz (Giga Hertz) and has nothing to do with the amount of pulses it transmits. Multiple frequencies in your Sea hunter means that it can transmit on any of its pre-programmed 22 frequencies and 750 pulses means the amount of pulses it will transmit on any one of the 22 frequencies it has selected at the time of transmission.  I think the main reason of multiple (22) frequencies is to reduce susceptibility to interference and secondary to ensure peak performance in different soils.  That's how I understand it.   I hope I am making some sense Allen.....