By Jim in Idaho
I've always had trouble getting the GB and Threshold exactly right on my TDI SL. After seeing Karelian's thread on the vernier knob, I decided to see what I could come up with. The problem with the control the guy suggested to him was that it had limited movement. Ideally, you want the vernier to turn as many turns as need to move the potentiometer through it's full range of travel. After hours of searching I found what I needed. A solid brass and stainless vernier with a 1:6 ratio. One full turn moves the GB pot about 1 1/2 numbers. I can now easily get the GB to that "just quiet" point, and it stays put. No more tree branches, or coat sleeves inadvertently moving the controls. I can easily set the Threshold to the very edge of my hearing, and as the batteries discharge and the Threshold creeps up, I can make a tiny adjustment and it's back on the money. As far as immediate and stark difference, this is the best mod I've done. It took me several hours to machine the bases, but the way I made it requires no physical mods to the machine. Remove the pot nuts, put the base on and replace the nut. I had to make shims for the pot shafts, as the verniers are made to fit a 1/4" shaft, and the shafts on the pots Whites used are .234". Had to make some very thin-walled round shims to glue inside the vernier sockets. I'm planning on selling these kits fort $150 for both controls, or $75 for a single. If anybody is interested, you can PM me here.
Now I'm really looking forward to our Nevada trip in June! My SL is about as good as an SL will ever be. It's going to be interesting.
So what would I dream White's would add and change on the Tdi Sl. Interesting to see what direction others would like White's to go in.
Not asking them to reinvent the whole system, just significant tweeks to breath new life into the Tdi machines.
1.Keep the light weight body. A well balanced detector that is super light and easy to swing all day.
2. Replace the mounting setup, like the old Tdi Pro, please use screws so I can hip mount the detector quickly and easily.
3. Keep using the same battery system, just upgrade to a 16 volt rechargeable, or 4 x 18650 system. Extra voltage matched with upgraded components etc Push the boundaries..
4. Retain the compatibility with MInelab coilts etc.
5. Upgrade the ground balance please, fine and course.. or a ten turn.... makes a big difference.
6. Yes I admit this sounds like a Tdi Pro in a smaller, lighter and better balanced rig. Only dreaming but far from impossible. Nothing mentioned here that has not been done by owners in the past as modifications of existing White's machines.
I can live without hipmount on such a light and well balanced machine, I've already pushed the battery system to max, at 16 volts. I'll keep a lazy eye out for a solution to the ground balance knob, I've seen a two tier knob etc. Just dreaming.
By South Padre Treasure
In a previous post few years ago, I read where a forum member I think it was REG was stating he had given Whites the information on how to do several modifications to improve performance.
I think this was about Dec. 11, 2016 1. build battery pack using Panasonic 3400mah. 2. modify filters to allow for faster swing speed. (reduce value of c20 and c21 from 0.47uf to 0.22uf).
and a few other changes.
After that said, the TDI SL I just purchased shows it is a 2015 model. Am I correct in thinking these mods. were not done at factory? I am going to open up my unit and check c20 and c21.
Also I purchased a Minelab Commander 15"x12" mono coil to try on my TDI SL. for Saltwater beach moderate mineralization. Will this improve performance better than stock coils or should I look at better options for the coil choice. I was hoping to also use for relic hunting at some old camp sites.
After speaking with Jim, I have ordered the Panasonic 3400mah batteries to build my upgrade pack, and if need be will try to mod myself.
I am new to this forum, have been hunting since 1994 or 1995. got away from detecting for a while then came back to my senses, forgot the motto you work to live not live to work lol.
I have learned more from reading the forums that I have ever learned by my mistakes. I hope I can contribute something to this forum and pay forward for all of the ones that have helped me!
Hey All, Measured White's TDI SL factory battery packs and discovered the following differences.
NiMh Battery - HD #802-5321, 2200 mAh.
After full a charge, one day later..........................................10.99 VDC AA Battery Holder - #802-7150, 8 cell.
With Nuon Industrial Alkaline from White's Factory............12.94 VDC With Member's Mark Alkaline from Sam's Club...................12.96 VDC With Energizer Ultimate Lithium...........................................14.46 VDC
Was very surprised that with Alkaline batteries, the tested voltage was higher than with the NiMh battery pack.
Also, the NiMh battery pack seems to drop about 0.05 VDC a day.
But the clear winner are the Energizer Ultimate Lithium batteries at 14.46 VDC!
Has anyone tried the Coiltek 17x11 Mono on the White's TDI SL? Would really appreciate any feedback on it's performance. Also, the Coiltek 14" round for the TDI? If positive, I'll order one and report my findings in a couple of weeks.
Maybe the battery mod later... Also checking on the SteelPHASE SP01 to enhance the audio...they said it would help.
By Steve Herschbach
This coil is being advertised at quite a few dealers now for $179.95. Which is great, available now for existing TDI owners. I had to chuckle though. They all are advertising it as “Whites 7.5″ x 12″ TDI HI-Q Dual Field Coil for MX Series Metal Detector”
Makes me wonder sometimes if I am the only one that notices stuff like this.