10" coil for Whites surfmaster dual field ...help

[Micheal]

Hi I need help to make a 10inch mono coil for my Whites surfmaster dual field detector....the factory 12 incn coil is too big and I dont like the dual field idea ,Has anybody made a coil for this machine that can help me ....Can i measure the resistance of the existing coil and try to match that resistance...what is the best way to tackle it as there is no after market coil available for it.

[mikebg]

Micheal, the 10 inch mono coil operates better than 12 inch coil in salty beach because the GND signal decays with smaller timeconstant. However for best results you should match three parameters: coil resistance, coil self-inductance and resistance of dumping resistor. The latter is necessary because your new search head and its cable will form a different stray capacitance.

[Micheal]

I havnt actually measured the coil yet to do so I have to desolder the coil from the circuit board......but please help me here ,...lets say for example if the factory 12'" coil measures 3ohms ,and I wind a coil10'' that measures 3ohms will it be ok to use without changing the damping resistor and will it be ok without causing damage to anything on the circuit board ...because I really dont want to touch the circuit.
I am thinking a single mono coil will detect deeper than a dual field coil ...am i correct in thinking this or not