WHITES TDI SL

[South Padre Treasure]

On the pc board of a Whites TDI SL there is a adjustable voltage regulator, what should the voltage be set at?
I have seen videos of placing a higher voltage battery in the unit. Any comments or mods that would help increase the performance would be appreciated.
P.S. are there any volume or threshold adjustments on the pcb?

 

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[Jim in Idaho]

You don't need to adjust anything, and shouldn't. Just use a 4-cell Li-ion battery pack, and you're good to go.
Jim

 

[South Padre Treasure]

Thanks Jim!

 

[Carl-NC]

SPT, the TDI has an adjustable regulator but the SL does not. The SL will tolerate a battery up to 20 volts or so, as I recall. It may help a little. Realistically, running a higher battery voltage requires some tweaks to the front-end to get the most bang for yer buck.

There is an option for a volume control. If you look near U21 (LM386) you should see pads for a 3-pin connector. This is for a volume pot. There are 2 fixed resistors that will need to come out, but I don't know the numbers... should be easy to figure out.

Not sure what you mean by threshold adjustment, since this already under user control.

 

[Jim in Idaho]

SPT, the TDI has an adjustable regulator but the SL does not. The SL will tolerate a battery up to 20 volts or so, as I recall. It may help a little. Realistically, running a higher battery voltage requires some tweaks to the front-end to get the most bang for yer buck.

There is an option for a volume control. If you look near U21 (LM386) you should see pads for a 3-pin connector. This is for a volume pot. There are 2 fixed resistors that will need to come out, but I don't know the numbers... should be easy to figure out.

Not sure what you mean by threshold adjustment, since this already under user control.

Great info, Carl, as always! I hope you'll post the details on the front end "tweaks". I'm running the 16v battery packs in mine, and while I'm really happy with it, any increase in performance is always welcome.:-)
Jim

 

[South Padre Treasure]

SPT, the TDI has an adjustable regulator but the SL does not. The SL will tolerate a battery up to 20 volts or so, as I recall. It may help a little. Realistically, running a higher battery voltage requires some tweaks to the front-end to get the most bang for yer buck.

There is an option for a volume control. If you look near U21 (LM386) you should see pads for a 3-pin connector. This is for a volume pot. There are 2 fixed resistors that will need to come out, but I don't know the numbers... should be easy to figure out.

Not sure what you mean by threshold adjustment, since this already under user control.

Thank You Carl! I will check it out. with the regards to replacing the battery, I see different ones have different amp readings, some protected some not. in your opinion what should I use and what voltage would be optimal for TDI SL. I have the 12 inch and 7.5 stock coils. I saw one person using the 18650 3400mah Panasonic NCR18650B cells QTY. 4 I will be using for beach hunting moderate mineralization, no nugget hunting around here just small gold jewelry. I respect your opinion greatly. Thank You! Disregard threshold comment. I did see a mod on earlier TDI Units for faster sweep speed I think it was. This pcb has more of the smaller micro components, im use to working on the old style don't want to make things worse.

 

[Jim in Idaho]

The sweep speed mod is fairly easy....the components are through-the-board. The other mod is fairly difficult. The surface-mount components are tiny, and I mean TINY! The SL's made since 2015 have the tiny component mod done already, from the factory. None of the factory units have the sweep speed mod done. The biggest benefit of the SS mod is in looking for tiny targets ie: nugget hunting.
Jim

 

[Carl-NC]

The Panasonic batteries are a good choice. Panasonic, LG, Sanyo, and Samsung are my top choices, just stay away from the cheap batteries as their capacities are grossly overrated and often have no protection circuit. Especially avoid any battery with "Fire" as part of the name (SureFire, TrustFire, UltraFire, etc).

Yes, the sweep speed mod is simple, although I'm pretty sure the 2 resistors you need to change are surface-mount. I don't recall which ones, someone on Geotech probably knows.

 

[Jim in Idaho]

One of them may be R9 that absorbs the flyback current...it tends to get a little hot with the increased voltage. I don't know about the other, either. I'm happy with mine after both mods, and the increased voltage, just as it is.
Jim

 

[EJZ]

I have the Tdi sl hi q. Came with the 12"x8" loop. Is the 12" round loop better.
I mostly use it for relics and beach hunting. I'm not in gold country. Thanks.