Menu
What's new
Find's Treasure Forums

Welcome to Find's Treasure Forums, Guests!

You are viewing this forums as a guest which limits you to read only status.

Only registered members may post stories, questions, classifieds, reply to other posts, contact other members using built in messaging and use many other features found on these forums.

Why not register and join us today? It's free! (We don't share your email addresses with anyone.) We keep email addresses of our users to protect them and others from bad people posting things they shouldn't.

Click here to register!

Need Support Help?

Cannot log in?, click here to have new password emailed to you

Modified Surfmaster question.

A

Anonymous

Guest
I purchased a used Surfmaster PI which already had the modification done to it. It is more sensitive to small gold but it also seems to be more sensitive to salt water. It signals any time that I move the coil off the bottom or if a wave goes over the coil. Is this normal? I can eliminate this problem by adjusting the pulse delay control but I wonder if I am then loosing sensitivity to small gold?
John
 
Bill,
I believe it is the same modification that you do. When I look at the board, the MOSFET and a resistor have been changed out. For all I know it may have been done by you. The guy I bought it from was the second owner and couldn't give me any information.
John
 
I know it sounds strange, but check it out with fresh batteries in it. It could have an affect on it. As I recall the power supply circuit is not the best design, and when the batteries get weak the pulse delay speeds up a bit. If it were to go from 15uS. to say 12uS. you could be picking up the salt.
It's not uncommon to have what you explained happen with any unit. Have you tried retarding the dealy any to see what would happen ?
Bill
 
Hi Mr. Bill,
Now you have sparked a question in my mind. I find it interesting that if the batteries get weaker that the pulse delay would be shortened. Also I am surprised that this would cause possible falsing because it would therefore pick up the salt. If this is the case, why would the Aquastar have a pulse delay minimum of 10uS?
Thanks,
Charles
 
Hi Charles and all,
The Aquastar coil and receiver circuits are designed to recover so that all transients and residual ringing is over well before sampling begins at the 10uS point. In the modified Surfmaster any shortening of the delay much less than 15uS will cause the sampling point to be on the edge of the recovery before the coil/ receiver circuits have settled down. This is an unstable situation where the additional damping of the salt water around the coil will be magnified and make the detector unuseable.
Eric.
 
Retarding the delay does correct the problem. I was just concerned that I was retarding it too much. I don't have to turn the control very far for it to help. -- John
 
You must log in or register to reply here.
Top