Silverdog Surf pi Daming resistor

[Tibuck19]

Yes Guys it me again lol you all know I do not own a oscilloscope YET, so I took an appoint me with a local electronic repair shop for tomorrow, to figure out the damping resistor with the coil I made. Can someone give a clear description on what I need to do, do I need a resistor already in place which one is it R2 ? .... TP1 and TP2 im guessing is where he will plug his oscilloscope? What do I need to bring the gentleman ? will doing this help sensitive on coins ? I know if I go with-in 2 feet of a car body the detector picks it up but when I place coins in the ground ( berried in snow in my case) I seem to lose depth compared to air test. Just to add more info my coil is a 10 inch 19 turns of 0.7229 magnetic wire.

[kt315]

George, is there an engine in forum to merge the same threads in one? its ordinary practic for forums but i do not see that here
a moderator doing.
that people again and again creating new threads and this flowing is huge. sometimes i am not able to find good answers in its i want to c/p.

[Tibuck19]

George, is there an engine in forum to merge the same threads in one? its ordinary practic for forums but i do not see that here
a moderator doing.
that people again and again creating new threads and this flowing is huge. sometimes i am not able to find good answers in its i want to c/p.

I tried searching the forums on this subject without falling on the right answer, I have read the mods some guys made by replacing the R2 with a 5K pot. but still doesn't indicate to a newbie like myself how to go about it . Perhaps it so clear to other and not myself.

[kt315]

http://www.geotech1.com/forums/searc...earchid=368749
two pages of the matter

[Qiaozhi]

George, is there an engine in forum to merge the same threads in one? its ordinary practic for forums but i do not see that here
a moderator doing.
that people again and again creating new threads and this flowing is huge. sometimes i am not able to find good answers in its i want to c/p.

Carl and I could spend (waste) a lot of time manipulating the content of the forum to keep it tidy, but basically neither of us have the time or inclination to do that. Occasionally we will set up a new project area for a specific design, but that's about as far as we want to go. The search function could be a lot better, but it works ok if you go to Advanced Search, select Search Single Content Type, set the type to Posts, and show results as Posts.

[Tibuck19]

Thank you once again Qiaozhi o'mighty GURU, id be total lost with out your help, after going back and doing the search again with advance and key words I found more suitable answers, I wish I known that last night before staying up to 3 in the morning digging though posts loll

[Tibuck19]

could one of you sketch out a little drawing, ( not electrical tech drawing, Just a normal drawing ) on how to make the adjustable damping resistor tool so I can bring it alone with me tomorrow, I know its most likely in the book but I will not have it till next mid week and I go tomorrow to the electric man with the scoop.

[kt315]

ok.
https://www.google.lt/search?q=wirew...otentiometer&*

[Qiaozhi]

could one of you sketch out a little drawing, ( not electrical tech drawing, Just a normal drawing ) on how to make the adjustable damping resistor tool so I can bring it alone with me tomorrow, I know its most likely in the book but I will not have it till next mid week and I go tomorrow to the electric man with the scoop.

Here it is ->

[Tibuck19]

Little Update on how this whole damping resistor thing went lol basically the appointment with local electronic shop was a bust! The gentleman offered me the use of the scoop and a variable resistor tool, but could not take the time to help me with it, Sadly I never seen let alone used a scoop so ! as nice as his offer was I am no further ahead, But he did offer me his tools anytime free of charge, So if I can learn how a scoop works I could use his. seems cheaper then buying one Right lol but how hard is it to learn how to use one without having one. Anyways, so coming back home I used my bread board and made the resistor tool that Giaozhi kindly drawn out after many hours of dancing with changing resister value ( which to take a measurement I had to unplug the coil, measure resistor, and plug it back in) fallowed by many a pond many air test and delay tuning, HAHAHAHA as you all can guess its not working out so well, For time being I settled on a 565 Ohm resistor which seems to work But ...... I still can't get more then 7"on a usa nickel and its scratchy at best. Brings me to a question, Is it even possible to reach 12 inch or more in depth with the sur pi 1.2?

[kt315]

you must load more power in the ground. for the depth. retune PULSE WIDTH on more value, 500us.... 1000us. change mosfet on 1500V 100A type.
change battery on another one, rackpack batt type will be good.

[Tibuck19]

you must load more power in the ground. for the depth. retune PULSE WIDTH on more value, 500us.... 1000us. change mosfet on 1500V 100A type.
change battery on another one, rackpack batt type will be good.

Would that be the offset or the delay pot?

[homefire]

Lengthen the on time to the Tx is what he's one about. Replace the Mosfet due to the work load.

[Tibuck19]

Lengthen the on time to the Tx is what he's one about. Replace the Mosfet due to the work load.

Makes sense, what would you guys consider to be a suitable replacement while staying with the same 11.4V 3 cell 18650Cell's

[Qiaozhi]

So if I can learn how a scoop works I could use his. seems cheaper then buying one Right lol but how hard is it to learn how to use one without having one.

https://learn.sparkfun.com/tutorials...n-oscilloscope