PI comparisons

[Anonymous]

Is there any place I can go to get some comparisons on the Whites Surf PI Pro, Garrett Sea Hunter Mark II and the Tesoro Sand Shark. I want a PI unit but just can't decide between these units I want to stay in the $600 range. Thanks for any help.

 

[Anonymous]

The first two are the better choices, the coil on the Tesoro limits its abilities.

 

[Anonymous]

There's no place like that I'm aware of.
Do check out the Detector Pro Headhunter PI.
Mr. Bill

 

[Anonymous]

WHY COMPARE. THE SURFSCAN BEATS 'EM ALL HANDS DOWN. MY 2ND CHOICE WOULD BE AN IMPULSE.

 

[Anonymous]

Thank you everyone.

 

[Anonymous]

Re the Headhunter, how many pulses per second? Can the pulse delay be adjusted? What is the minimum pulse delay setting? Is the volume adjustable and/or can signals be heard over SCUBA?

 

[Anonymous]

Tim
Pulse delay: 15 - 50 uS
TX width: 30 - 150uS
TX frequency: 10,000pps - 2000pps.
Volume adjustable.
The owner of the Headhunter company is a diver with SCUBA. He uses his unit a lot, but on the hearing thing a lot depends on your hearing, and the surounding conditions. This applys to any unit, not just the Headhunter.
Mr. Bill

 

[Anonymous]

Hi Mr Bill
is "10000pps" the same like 10kHz?
Chris

 

[Anonymous]

Chris,
With PI pulsed waveforms that typically have much less than 50% on duty cycles, the term PPS (pulses per second) is a more accurate way to describe the pulse speed than using the term KHz. I have seen the pulse speed refered to both ways but the term PPS clearly refers to PI machine pulses as distinctly different from VLF machines that work in the low KHz range.
I'm sure there are other better explainations.
bbsailor

 

[Anonymous]

A little more technical explanation:
The term "Hz" refers to cycles per second. In the case of sine-wave excitation of the transmitter coil,
a cycle consists of a positive-going half-cycle followed by a negative-going half-cycle.
In similar fashion, a PI cycle usually consists of a positive pulse, followed by a negative pulse.
A 10 kHz operating frequency therefore corresponds to 20,000 pps.
A synchronous demodulator inverts the polarity of every other signal sample received, thus adding the target signal samples. In contrast, asynchronous signals, such as might be induced in the receiver coil by magnetized rocks ("lode stones"), are cancelled, along with DC offsets in the amplifiers.
I hope this helps...