Tesoro Cutlass II umax modifications

[Cadmaster375]

I JUST picked up my first detector a tesoro cutlass II umax and from reading here and other places their are several mods that can be done to improve the detector. I know sven did one and see that several more might be possible. any thoughts on which mods I should do after I get this thing figured out?

I got the detector for $100 CAD ($76 USD) from my local Kijji. An elderly man had bought it new for finding his property stakes so it has minimal usage, no manuals or accessories like a coil cover.

Did I get a good deal? I know it is a beginner detector, but I thought a decent built beginner detector is better than no detector and it gets me out in the field.

[FatBob]

The Tesoro's are decent detectors especially around iron, though the newer ones go a bit deeper.

I picked up a Cutlass Umax that was broken and plan to mod it to use a Fisher CZ coil to see if it
will go a bit deeper. Right now I am setting it up on a mini shaft for my daughter to use as her
first "real" metal detector.

The newer Tesoro's are made on a substrate so some circuit mods cannot be done.

[Cadmaster375]

just popped to cover off to have a look and it has no substrate.

[Koala]

I have been using my Bandido for about 6 months now. Very good on my ground. Strange thing is it match its air test in the ground. Not sure if that's because it of the interference in the house. My IDX looses about 1\3 in the ground verses air test.

I believe the cutlass II was very similar to the silver sabres II. So performance should be adequate as it is.

[FatBob]

Wow they went back to discrete components so that means the sky is the limit to mods!

It looks like they left some stuff out, maybe you can figure out how to add it back?

Here's my cutlass;

[Cadmaster375]

well that detector is growing on me! bought it Friday went out Saturday and got $2.35. went out this morning and scored 3.35 and a 20" 10k very heavy gold chain. I guess my little projects will get a jump start! project 1 waterproofing the detector.

[Cadmaster375]

started ordering a few components for water proofing the detector. I am going to modify it in stages so I can afford it. purchased a guide series Plano waterproof box and some waterproof cable connectors for the coil. I plan to replace the 4.7uF caps with 10uf caps add a waterproof external power toggle and a waterproof toggle for switching between all metal and discrimination, I also plan to replace the stiff fragile wire Tesoro uses to connect components with longer braided wire. also just purchased a Garrett carrot to speed up hunting. I know the plano box is only rated ip67 and not 68 I plan to use plenty of silicon lube on the o ring and cool the unit a bit before closing the box so when it is in the water it has a higher pressure internally. I could also add a tire valve and use a small hand pump to raise the internal pressure 10-20 psi. since I plan to only be wading I doubt that would be necessary though.

[SVEN1]

Planos will leak, pressurizing will not solve any leaking problems. Discussed in other posts regarding waterproof box.
Get yourself a White's Beach Hunter ID box or Dualfield box, sometimes White's may sell you one.
If your water hunting, more than likely you detector box will not be submerged underwater the whole hunt.
For extra safety measure, buy some swell sponges, place them on the box bottom mostly the front of the box that is angled towards the ground, any water leakage will go to
boxes most lower corners. The sponge will soak up the water, before it does any circuit board damage like saltwater does. make sure you have a silica gel pack in the box as well.
You don't want condensation developing. I always crack the box lid during storage.

Plenty of silicone lube is not the answer. When using silicone lube, you want a very very light almost non-existant film. Some o-rings no longer need the silicone lube, some o-rings are actually damaged by silicone lube.
Never use petroleum jelly as a lube.

Reminder
A fellow water hunting, made a good post as a reminder to those that are long time water
hunters or are new to water hunting. It is reposted here:
Sometimes the laws of physics are at play without us even being aware of them. For
instance, if you take a plastic sealed container, put a small pin hole in it and submerge it
hot water, you will notice shortly that air bubbles will start to leak out under pressure,
simply because the inside temp is warming up, causing a positive pressure.
Now reverse the conditions. Warm the plastic container up, and place it in cold water.
What happens? The cooling of the temperature caused a low pressure or vacuum to appear
inside the container, and in order to reach an equilibrium, it sucked in water.
Watch how hot your equipment is before you submerge it in cold water. A metal detector
in the car trunk or in the car with the sun shining on it will cause it to get extremely hot.
By putting it in the cold water, you are causing a tremendous amount of vacuum to be10
produced as the the inside of the coil, connector or electronics box tries to reach an
equilibrium of pressure. Create enough vacuum in the coil, connector, splicing, electronics
and you might get some leakage. Please......cool your equipment off before suddenly
submerging it in cold water. This is true for all makes and models of detectors. Although
leaks can occur for many other reasons, this should surely help.

[Cadmaster375]

thanks sven for the info.

Btw has any one tried to mod the Tesoro's with the dual tone from the TGSL dual tones mod? is it even possible?

[Cadmaster375]

Got my equipment orders out and parts are all ready starting to arrive. My order from digikey (waterproof switches, boots, 9v battery connector, caps) only took less than a day from ordering to delivery. 8 days into the wait for my 5 pin ip68 wire connectors from china, should be another week or so for them. then to start construction.

[Cadmaster375]

Swapped out the 4.7 uF caps with the 10 uF caps and everything seems to be working well.
I ran some air tests for comparison with the chart Sven made and it looks like I gained a couple of inches depth. desc was set at around 1 and everything else other than the 2 caps was stock with the standard brown donut 8" coil. the test was quick and dirty and I recorded the depth when the tone was easily repeatable and would be something I would dig.

Canadian currency air tests.
1944 1 cent desc = 9.5" all metal = 9.5" (copper)
1997 1 cent desc = 9.5" all metal = 9.5" (zinc)
1968 5 cent desc = 8" all metal = 9" (50% silver)
2015 10 cent desc = 8" all metal = 9"
2006 25 cent desc = 9" all metal = 9"
1994 $1 loonie desc = 10" all metal = 11"
2005 $2 toonie desc =9" all metal = 10"

[SVEN1]

Just remember the Cutlass is just like the Silver umax, it does not have a true all metal mode.
Just discrimination mode. Tesoro fools you into thinking it does have all metal mode.
All metal mode is just a lower disc.setting that accepts more iron.

Disc mode for example using chart below runs from 40-180
All metal (disc mode) runs from 20-180

That's why you don't see much if any increase in air test depth between the two settings.
Generally the higher you adjust disc, you lose sensitivity and depth to smaller targets.
With a gain and sensitivity control(s) you could get some of the loss back, along with some noise.

[Gwil]

Hi Sven1

Could you explain what you mean by "a true all metal mode"? If you can point me to a detector that does have this feature I may be able to find a schematic for it and see what's going on.

Thanks,

Gwil

[SVEN1]

http://www.detectorprospector.com/go...ixed-modes.htm

[Gwil]

Thanks. I will carefully study that.