Surf PI Pro

[Silver Dollar]

A typical 5V regulator wants 7.5V or more to run. The problem is the extra juice gets converted to heat.
If you had a LDO (Low Drop Out) regulator they need much less to run. The PI TX likes 12V to make some
high field strength. 4 LION cells would give you 16V! 3 is 12V and would be better. Maybe you can mod
the board a bit and use 2 to generate 5V and 3 or 4 for the 12V?

[CalebG]

I must confess I did not look closely enough at the schematic. I did not see the 12v tied directly to the mosfet. It makes much more sense now, I didn't want to waste battery juice on the regulator if it was unnecessary, I did use the LDO version, so I think it only requires +1.25v over regulated (6.25v total) I will look to see if it would be feasible to feed the regulator off two batteries (7.4v approx) and feed the coil off three. They will have to be wired separately anyway for the lion charge controller, so it might be an easy modification. So my next question if 12v to the coil is good would 14.4v be that much better? If the regulator wasn't having to shunt the extra voltage away it would only be traveling over the mosfet, shunt resistor and coil.

[nando.22]

surf pi pro james owen test http://www.youtube.com/watch?v=XITYwS5KxwE

[bob808]

Hi guys.
I want to build my first detector
So far I like this project as it's well documented. But I have a few issues to sort out.
First, I'm not sure if this would be recommended for me. I have no beaches near and as far as I know the Surf is recommended for exactly that.
I won't have much time doing prospecting, I want to just have the option to go out and have some fun with a detector.
I'd build one that's good and is very well documented. I've done some electronic projects and have proper tools for hobby/diy.
So, what would you recommend? I saw another project but didn't have the time to read as much as I did on Surf. It's Serbian "Most Wanted".

[kt315]

surf is the best machine to get your first experience and to grasp the principles of how PI working.
do it. but real machine you need is tesoro clone because tesoro has a discrimination. surf is working on all metal mode,
it is yes best for only beach and underwater, that was projecting the surf for primary.
do not do most wanted because much noise from serbians, no real deal. do TGSL or white classic at second your step.

[Qiaozhi]

Hi guys.
I want to build my first detector
So far I like this project as it's well documented. But I have a few issues to sort out.
First, I'm not sure if this would be recommended for me. I have no beaches near and as far as I know the Surf is recommended for exactly that.
I won't have much time doing prospecting, I want to just have the option to go out and have some fun with a detector.
I'd build one that's good and is very well documented. I've done some electronic projects and have proper tools for hobby/diy.
So, what would you recommend? I saw another project but didn't have the time to read as much as I did on Surf. It's Serbian "Most Wanted".

Some options for you:

1) Tesoro Golden Sabre Lite (TGSL) -> http://www.geotech1.com/forums/showt...mplete-Details
2) MiniPulse Plus -> http://www.geotech1.com/forums/forum...Minipulse-Plus
3) Silverdog website for detector kits -> www.silverdog.co.uk
4) "Inside the METAL DETECTOR" -> Inside the METAL DETECTOR - Published September 2012

[bob808]

Oh, thank you for the guidance!
I took the liberty to tinker with the Surf PCB. I've made it smaller, so it fits 10cmX5cm. That way we could do a double sided batch at Fusion PCB or similar. I've done some math and it seems that for minimum of 5 boards the cost is 4$ per board, but if we managed to get 10 boards, it goes down to 2.4$ per board. That's with shipping
The trouble is that someone on the forum, maybe an authoritative figure would be recommended to do the stuff. No gain for anybody, just pcb+shipping cost. Well, maybe group buy admin keeps a free pcb if he bothers with the whole deal And then there would be the cost of shipping from admin to users.
If there's interest and you'd like me to fiddle some more with the PCB do tell me.
Meanwhile I will read the material you recommended.
Also the pcb features mounting holes, and is double sided with ground plane on top.
If you'd like to make some suggestions regarding the layout please do. Even if we don't make a group buy I may get some boards at some point. For 20$ I would be happy to have some pcbs made by me

[Silver Dollar]

I'd be interested in a couple of those boards. A few of the projects I have built
work fine but need huge cases so I'mm looking for smaller stuff...

[bob808]

Did someone model this schematic in Spice? I think I saw it at some point but I'm not sure.
I'd like to see if I could replace some of the passives with 1206 smd packages. They are easy to solder even for beginners and would clear up the board some more. The plan would be to still use sockets for repair ability in the future. Usually at build up passives go bad harder then IC's.
And SMD caps would better help with decoupling noise from chips. I can put them very close to the chip pins.

[kt315]

do not waste a time. buy SMD board from Carl on HAMMERHEAD PI and do what you plan. you can call your project the surf pi or pirate pi or marauder pi or snoopy gold pi.

[bob808]

Does he have a SMD for Surf PI? I could only find the Hammerhead. And only through-hole. On his site.
I did something like this, it's really small like 5cmx5cm and would be real cheap, like 1.5$ for one board if 10 are ordered. With shipping included
I should clean it up some more but should come out ok. Need to analyze de spice model to see if parts meet the requirements in smd package (like power req).
I also adjusted the electrolytic capacitors footprint based on their value from the common ones found all over the place. Also I removed the pots and only fitted holes for them. It's not going to be pretty with all the wires coming out of the board but it's small and should work .
If Carl has something this small then I might drop the SMD project and maybe do the 10x5 version for the through hole.
I also added a photo of a 5x5cm board next to a zippo as a size reference

[Silver Dollar]

I like that tiny board but all SMT caps would even be better!

[bob808]

I will try it

[6666]

Bob i will buy a through-hole pcb from you but not SMD

[kt315]

SMD is hard to solder. if you want I'l put HH SMD board free, no charge, with Delta Pulse board if you order.