Surf pi detector-MOD

[GeoMax]

Recently, I was looking into the SurfPI's circuitry and discovered that there are different SurfPI models. I hadn't realized this before. I always thought all SurfPI’s are SurfPI’s. I did notice differences in the TX coil circuitry, but I always assumed those were just modifications someone had made.

Here are the most noticeable differences between the SurfPI and the SurfPI Pro. The SurfPI Pro is the successor to the SurfPI.

SurfPI:
The external controls are PULSE DELAY (15..40us) and the TUNE (threshold) potentiometer. The internal settings are a preset for the pulse delay (min 15us) and a kind of fixed “GAIN/S.A.T.” circuit.

SurfPI Pro:
The external controls are GAIN and TUNE (threshold) potentiometer. The internal settings are a fix preset for the pulse delay (15us) and a kind of variable “GAIN/S.A.T.” circuit.

Any SurfPI detector can be converted into a SurfPI Pro detector. Just search for "SurfPI modifications by Mr. Bill."
In addition to the SurfPI and SurfPI Pro models, there's also the latest model released by Whites, the SurfPI Dual-Field. This model features all three controls (PULSE DELAY, GAIN, TUNE) as external controls.

[kt315]

Just search for "SurfPI modifications by Mr. Bill."

Bill Crabtree had very huge list of mods on different models but shared just on IDX, after I told the mod. i think you are under 'Mandela Effect'.

[GeoMax]

Hi KT315,

here is the search results (to the "Mandela Effect") on Mr. Bills modifications on the Surf PI.

Just found this post from Mr Bill on the Wayback Machine, Findmall Modifications:

"...Increase performance considerably on your Surfmaster PI toward small gold jewelry. With a simple modification you can end up with a 15µS pulse delay. from a factory 22/24 µS.. This a very noticable modification that can be returned to factory specs with the adjustment of the external pulse delay control. Replace #Q2 (TIP 32 C) with an IRC 9640 MOSFET. It is a direct replacement. Replace resistor R6 220 ohm with a 390 ohm one.Re assemble leave board loose so you may get at trimmer R25. Turn on, set threshold to just hear audio hum, set pulse delay to minimum setting. Using a 1/2" square piece of aluminum foil run it by the coil, adjust R25 to give best response on foil. Your all done, re assemble..."

And here is the circuit diagram notes to it....


Have you (KT315) suggested the mods to Mr. Bill?

[kt315]

yup, this schematic with Eric's mod and Terry's mod. my red color selection. no Bill. Findmall? and what i must to know what he wrote there? anyway, he just noted-repeated mods of Eric and Terry.

HE HAD HUGE LIST OF MODS HE DID NOT SHARE NEVER, with the prices -!

[GeoMax]

Hello KT315,

Do you know of any other mods for the SurfPI that you don't see here and can share?

[kt315]

Hello KT315,

Do you know of any other mods for the SurfPI that you don't see here and can share?

every your mod you just mind... and you want to release... will be one from HAMMERHEAD-PI. Carl did huge job. do not see that is your very big problem.
all was released in 2003 year (oh my dodge!).
also, Carl had shared a schematic of Whites, fabric, original. i sure do not want to be back to this matter...

[GeoMax]

Hello KT315,

Sorry, but I don't plan on republishing all the SurfPi mods here. And I also know what you and other forum members have posted on the topic in the past. I just want to gather the information, even the information I may not have yet. I've known about the SurfPI Pro & Clicker diagram since the day Carl posted the schematic in 2012.

But if you don't want to be confronted with the old SurfPi topic anymore, that's fine. Others might still be interested in learning about these modifications.

[Qiaozhi]

Hello KT315,

Do you know of any other mods for the SurfPI that you don't see here and can share?

There is also (of course) -> Arduino Nano Pulse Induction Metal Detector Project - Published March 2021
The underlying architecture is based on the Surf-PI.

[GeoMax]

Hello Qiaozhi,

Thanks for your contribution. I also own all of your recently published books. They are a fantastic source of information, and I have already recommended them to other DIY enthusiasts. Inspired by your Arduino Nano project, I'm currently learning how to use the Arduino for DIY projects. The first new project ideas with the Arduino Nano and Arduino Mini Pro have already taken shape. New operating functions for these projects, such as a "one-button operation" with a display, have already been defined and just need to be programmed. The corresponding PCBs for these projects have already arrived from China.

This is an example PCB from one of the Arduino projects I'm currently working on.

[Ruben2000]

Hi Ruben2000

you can find the schematic here in the forum at this link, post #1 Surf PI Pro - Geotech Forums

Hi Geomax!
I skimmed the entire thread quickly and found it very interesting.
Several people have built their SurfPI Pro using the Surf XX PCB, and some come with or without the 7660 oscillator input connection. Both are feasible.
There are several points to consider when assembling this MD.

[Ruben2000]

Hello Qiaozhi,

Looks great!
What's your detector called?

[GeoMax]

Hi Ruben2000,

I call this project "SurfScan PI Nano". If you zoom into the PCB image, you can read it there too. This is not the SurfPI circuit published in Qiaozhi's book Arduino Nano Pulse Induction Metal Detector Project - Published March 2021, but the timing part of this project is similar like the Arduino Nano Pulse.

[GeoMax]

Hi Geomax!
I skimmed the entire thread quickly and found it very interesting.
Several people have built their SurfPI Pro using the Surf XX PCB, and some come with or without the 7660 oscillator input connection. Both are feasible.
There are several points to consider when assembling this MD.

The 7660 has an internal oszillator running a about 10kHz and works as well without oscillator input (sync) connection. Thats why some people do not synchronise it with the TX circuit.

[Detectorist#1]

The idea of synchronization is to stop 7660 during RX samples and to avoid additional noise in RX channel. But the working frequency of 7660 is too far from useful signals and the filters in RX channel effectively suppress this noise and as a result - synchronization of 7660 not add improvement to the capabilities of the detector.

[Ruben2000]

The 7660 has an internal oszillator running a about 10kHz and works as well without oscillator input (sync) connection. Thats why some people do not synchronise it with the TX circuit.

You're right, reading all this I'm beginning to understand how each component actually works.