Myers Depot Metal Detectors

White's Surfmaster PI Mods

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cobill

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Jan 1, 2014
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Was thinking about buying a Surfmaster PI and read lots of posts about Mr Bill's mods. His website is now gone and I was wondering if anyone does the 15uSec mod for the best response on gold?:?:

Surely the mods Mr Bill made were not just adjustments on the circuit, he mentioned he "modified the circuit to allow it to go down to 15uSec".

Thanks,

Bill
 
I would suggest the Geotech forum. I know Gary Storm and Carter had the delay knob set up so they could adjust the delay if they hit a faint target. They hear a target they would turn the delay up..if it went away it was gold? Been awhile .... I'm not sure how much they adjusted it but you can see in Carters video on the DF he has the delay knob so he can adjust it easy.

You can see it and him adjust it at ..2:26 to 2:40 very easy..

https://www.youtube.com/watch?v=3pNtGN6rWYk&t=40s
 
cobill said:
Was thinking about buying a Surfmaster PI and read lots of posts about Mr Bill's mods. His website is now gone and I was wondering if anyone does the 15uSec mod for the best response on gold?:?:

Surely the mods Mr Bill made were not just adjustments on the circuit, he mentioned he "modified the circuit to allow it to go down to 15uSec".

Thanks,

Bill
Click to expand...

Most of the Whites detectors are set at 15uS already... I know the Surfmaster was as well as the Dual Field

I went up to visit Bill and we ran it thru his test garden he was going to tweak the DF but I heard the nickel he buried at 15 inches in the loamy sand mixture and we decided to just shoot the breeze...

Bill is retired but I still talk with him on occasions..
 
Thanks Cfmct,

Found this 2010 reply from Mr Bill that I was interested in:

"Hi Guys

Yes I still modify the Surfmaster, and Dual Field Whites PI units.

A little explanation.

With the earlier versions of the Surfmasters I extend the pulse delay range making it quicker, (shorter) than the factory. I have found the factory to be very inconsistent in their settings, ( it should be 18µS ), leaving the pulse delay between 18 µS. and 22 µS..I modify the circuit to allow it to go down to 15 µS.. At any time, one can return to factory settings by just retarding the pulse delay control. This should address your concerns about it changing the unit, and making it a bit unstable.

On the Surfmaster Pro, that’s a copy of the modifications I did to the Surf PI with the addition of the gain control, and the removal of the pulse delay control. I still do work on them because they come out of the factory in various stages of adjustment. I set them up on a scope, and tune them in for the best response to gold jewelry.

The Surfmaster Dual Field is a continuation of the Surfmaster PI and PI Pro. They re-instated the external pulse delay control, and installed a dual field mono coil on it. The not so sharp adjustment from the factory continues on the Duel Field. So I stay busy tweaking them also.

FYI: The Dual Field coil was a design by my friend Eric Foster that he did for Whites while designing the TDI PI for them.

So there it is in a nut shell."

Mr. Bill
 
All I can tell you is we looked at mine and he told me it didn't need tuning he said yours is right where it should be...
 
I have similar posts from Bill many years ago...if not the same your referring to. I have one that I purchased new and it's pretty mint. I have babied it for 20+ years. I agree, no discrimination sucks, but I find very little iron on our beaches unless it junk jewelry. I would never use a PI on land unless I'm in gold country or hunting relics.
 
cobill said:
Was thinking about buying a Surfmaster PI and read lots of posts about Mr Bill's mods. His website is now gone and I was wondering if anyone does the 15uSec mod for the best response on gold?:?:

Surely the mods Mr Bill made were not just adjustments on the circuit, he mentioned he "modified the circuit to allow it to go down to 15uSec".

Thanks,

Bill
Click to expand...

There was a capacitor that was changed. A simple unsolder/resolder... or so it may seem. I found the schematic years ago, but never wanted to tinker with my baby.
 
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.
 
Cool, It's been so long I thought it was a capacitor. Although you can change either in the same circuit to change frequency. I built a few stereo amps back in the very late 80's\early 90's, but family life took over those ventures. I'll see if I can find the schematic. I know I saved it... somewhere.
 
cobill said:
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.
Click to expand...

Pretty straight-forward. Now all we need is a legit schematic of the circuit. I haven't had the board out to look at it and see if the components are labeled...usually they are, but you never know. There will be many transistors and resistors in it. Just need to know which to replace. And then just add the new adjustment potentiometer...simple...right??? LOL
 
Well after reading this again I see R25 (potentiometer) is already there. Just have to adjust after replacing the resistor and mosfet. Easier yet. Me getting tempted!!!
 
Yeah, I thought the thread sounded familiar, Your quote was from a thread of mine in 2010. I regret never sending it to him to get it modified, but I have been impressed on it's sensitivity to small earring backs. I have found several of them and they are a ***** to find in the sand. I can't complain about it.
 
cobill said:
Craig said they were great PI units and that is why I'm still looking for one.

Bill
Click to expand...
If your use to a clean threshold.. don't get one.. to much chatter for me.. Sorry that is the DF.. the surfmaster is the before I think..
 
OBN said:
If your use to a clean threshold.. don't get one.. to much chatter for me..
Click to expand...

Oh yeah...they chatter like no-bodies business. Music to my ears. You should hear my M6 cranked to the max running over iron-infested ground. OOOO-Baby!!! And it doesn't have threshold!!! lol.
 
Surfmaster, Surfmaster Pro, then the Dual Field. Don't mix it up the the DF (Dual Frequency) land unit (non-waterproof)-(between the XLT and V3). If I understand correctly, they took the pulse delay off the Surf Pro and increased the gain while reducing the circuit frequency to 15-18 mhz. Mr. Bill's mods moved the Surfmaster (non-pro) to the 15 -18 range with the original pulse delay control (best of both worlds). The Dual Field had two coils, making it a top performer. Never used one...so I'm going by other's observations. Craig could give more info on the dual field.
 
Florida Tabdigger said:
I have similar posts from Bill many years ago...if not the same your referring to. I have one that I purchased new and it's pretty mint. I have babied it for 20+ years. I agree, no discrimination sucks, but I find very little iron on our beaches unless it junk jewelry. I would never use a PI on land unless I'm in gold country or hunting relics.
Click to expand...


Don't listen to KOB he is a pulse hunter he doesn't want others to know how good they are.... :yes: He rather you use a NOX... ;)
 
Florida Tabdigger said:
Surfmaster, Surfmaster Pro, then the Dual Field. Don't mix it up the the DF (Dual Frequency) land unit (non-waterproof)-(between the XLT and V3). If I understand correctly, they took the pulse delay off the Surf Pro and increased the gain while reducing the circuit frequency to 15-18 mhz. Mr. Bill's mods moved the Surfmaster (non-pro) to the 15 -18 range with the original pulse delay control (best of both worlds). The Dual Field had two coils, making it a top performer. Never used one...so I'm going by other's observations. Craig could give more info on the dual field.
Click to expand...

DF was deep but noisy as hell especially the deeper you went but pin pointing was amazing.. a lot hated how noisy it was but I didn't mind it..
 
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