Carl - HH PI and 1m coils?

[rgecy]

Carl,

Could you give as many specifics as possible on constructing a 1x1m coil for the HH PI and any additional components needed. I am interested in putting it on a tow fish with about 50' of cable like the Fisher Pulse 12. Any help would be appreciated.

RGecy

[Carl-NC]

I think I used 7 turns of 24AWG. You will need to alter the oscillator circuit, get it down to 100 Hz or so and maybe stretch the pulse width. Then, tweak in the damping resistor. It's been a while since I messed with this, so I'll have to see if I can dig up my notes.

- Carl

[rgecy]

Thanks Carl for looking into this. I am a novice at electronics and know just enough to get me in trouble. But if you give me specific directions on how to do what you said, I can do it successfully.

Thanks again,

RGecy

[Boattow]

Pulse 12

If you are going to tow 50feet of cable, you will probably be ok. In addition to what Carl says, you will have to back off on the pulse delay as well with all the extra capacitance of the coax cable but that shouldn't be a problem. Also you will want to protect the cable by putting it in a hose or some other jacket to keep it from being cut or damaged. You won't get exactly what a Pulse12 is capable of because JWFisher puts the pulse circuit and front end remote in the water with the fish. I think the end result of this primarily is being able to run the pulse delay a little shorter which allows you to pick up smaller items and a little more sensitivity on larger items. Most people aren't looking for small items when towing a large coil though so it shouldn't be a problem. According to Eric Foster, the units he designed for Mel Fisher didn't remote any electronics. Incidentally, I own a Pulse12 and the quality of it leaves a lot to be desired.
Good luck,
Boattow