Modified Harbor Freight Pinpointer w/ pics

Would painting it white help to cut down the heat issue by not absorbing as much heat from the sun? Maybe a white pouch for it too?

Just a thought from one who knows absolutely nothing about electronics and mods...

Later,
Brian

mine seemed ta have more of in issue in cold weather
 
a slightly different mod

My apologies to whomever I stole this idea from. I saw a picture of the completed project where someone else put the wand of their centech probe on a wire, and I decided to do the same. I like the idea of strapping the box to my belt and using just the probe when I'm digging.

For those of you that might be interested, I used an old network cable (Cat5) and cut the ends off. Each coil uses one twisted pair, which should help preserve the signal over the longer wire run. The wire is about 4 feet long, and it still works great. I also cut a couple extra holes in the stock carrying pouch to get at my switch and sensitivity dial.

I also added a cell phone motor, which I put into the probe itself - I just used another pair of the wires in the cable to run power out to it.

To add the motor the way it was intended, you need three things:
1) a connection where the switch is supposed to be. You can see in this picture I've just got it soldered closed just like the buzzer comes from the store.
2) a resistor at R14. In my picture, its the larger tan one in the back. I used a very low-value resistor (68Ohm) and it works fine.
3) a motor. Once you've got the other two pieces in place, the little motor connection points are "live" so you can wire the motor right in at that point - no more need to splice onto the buzzer capacitor.

Might be more mods to come for this little guy, we'll see. :)

Valhad
 

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Picked up my centech last night. That's a great little tool for $16 and change!

It's on the workbench at the moment waiting for the spray on rubber to dry on the wand. Can't wait to try it in the field!

Valhad, I might try your remote wand mod. My version might be detector mounted, with a little clip to quickly remove the wand for pinpointing.
 
holy !!!! i want to do this but it looks confusing? lol im circuit board illiterate.

How long did this take to do? and can you post step by step?

I dont want to put a motor in it, just want to extend the probe like you did. Studying the pictures it doesnt seem to hard but i only see 6 wires, Orange/Orange white, the 2 greens and the 2 blues, i have a cat5 cable here and it has 8 wires, so where are the other 2 wires soldiered to?
 
holy !!!! i want to do this but it looks confusing? lol im circuit board illiterate.

How long did this take to do? and can you post step by step?

I dont want to put a motor in it, just want to extend the probe like you did. Studying the pictures it doesnt seem to hard but i only see 6 wires, Orange/Orange white, the 2 greens and the 2 blues, i have a cat5 cable here and it has 8 wires, so where are the other 2 wires soldiered to?

i would think you could just splice a longer cable onto the probe and it would also work, i put a micro vibrating motor on my backup centec and its much nicer than that horrible beeping, i just cut the speaker and spliced in the motor.
 
Well I'm stuck. I got 4 wires soldired on the circuit board but now I can't figure out what copper wires from the wand go to one of the 4 I added. Also if I touch 2 wires together I get a constant beep, the other two I touch I get nothing. I'm at a total loss right now and have no idea how to fix it
 
If you only want to extend the wand, you would only use two pairs of the wire. Alternately, you could use telephone wire (although I'd recommend in-wall wire, which should feel pretty round.) Telephone wire is typically also twisted pair, and would have only four wires in it, so it wouldn't be as stiff as my Cat5 choice.

The wand mod itself probably took me 3 hours, but most of that was working with the case trying to figure out how to secure the wire in the gaping hole left from the wand. :) If I had it to do again, I'd just get rid of the LED, widen that hole a bit, and use that opening to run my wire.

As far as step-by-step, here's about the best I can provide, for the wand-only modification:
1) remove nut and bolt from the center of the unit that hold the wand in place.
2) lift the board and wand from the back of the case. the box-top, where the knob and LED are, lifts up out of the back.
3) remove the box-top from the wand. It's just held on by hot glue at this point.
4) inspect the four thin copper wires. You'll see on the board that they are marked as pairs, with something like |____|o next to each pair. On my pinpointer, the original wire that went to the __|o side had a little knot tied in it. If yours don't, consider marking the wires with a sharpie or something.
5) splice in the longer wire. You can do this two ways:
A) The safe way, by removing one wire at a time from the board, attaching that wire to one of your Cat5 wires, then attaching the other end of that Cat5 wire to your board. This is the safest possible way to avoid mixing up the wires. It is a bit clumsy to work with, though.
B) The labeling way. Mark your wires however you see fit (I used a piece of tape folded over to hold one pair of wires together.) Unsolder all four wires. Attach the wires to the board. Attach the wires to the wand.
6) NOTE: whether you do A or B, above, make sure you consider how you're going to run the wire. For instance, if you want to run it through the LED hole, you'll need to modify the box-top a little and run the wire through it BEFORE you attach both ends of the wire to their destinations. Same goes for the wand end. If you want to put a fancy handle on it, that'd need to go on before you attach the wire to the wand. :)
7) with all the wires re-attached, it should work now. Test it before you continue.
8) attach your cable to your wand, and to your pinpointer case. You don't want tugging on the wire to pull the wires free from either end. Hot glue is your friend.

I "attached" my cable to my wand a couple ways. the best method I came up with was to take a longish twisty tie (you know, the plastic-covered wire ties that hold bread bags closed and make tidy bundles of power cords on packaged electronics) and run it up though the bolt-hole on the wand, around the new cable, then back out. Twist it nice and tight, then I brought the legs
of that tie up around the cable again, near the pointiest part of the wand, and twisted them together here too. This held the wire pretty well. Then I sealed that all together by filling the end of the wand with hot glue. I also filled that little hole in the side of the wand (where the wires initially come out) with glue so that it'd be a bit more sealed against moisture. Then I wrapped it all in electrical tape, just to make it prettier.

jgray44: I hope this helps. If you've got your wires mixed up, I think the only way to un-mix them would be to use a voltmeter / multimeter to figure out which wires go together. If you have a decent one with continuity testing as an option, just use that to sort them. If you don't have a continuity tester in your multimeter, or don't have a multimeter, head over to harbor freight and pick up the cheapest one they have. It's usually 4-7 dollars. It won't have continuity testing, but you can use the resistance to tell you the same thing in this case. Hopefully your wires also came with little knots in them to identify which end goes where on the board. Send me another PM if want me to walk through how to use the multimeter in more detail.

Darter: if you rig up a way to clip it to your detector, I'd love to hear/see what you come up with. That'd be slick. :)
 
I remember seeing the knots in the wires that u are talking about. I cent work on it right now since its at a buddies house. The only weird thing I noticed was if I take a little led light and attach it to one set of the wires the light would light up. If I did it to the other two wires it wouldn't light up. Starting to wonder if I fried part of the board.
 
I remember seeing the knots in the wires that u are talking about. I cent work on it right now since its at a buddies house. The only weird thing I noticed was if I take a little led light and attach it to one set of the wires the light would light up. If I did it to the other two wires it wouldn't light up. Starting to wonder if I fried part of the board.

Looking at the wiring diagram, that doesn't sound like a problem. The coil on the left in the diagram would complete a circuit with an LED, the one on the right probably wouldn't light it up. I doubt you've fried it yet, just gotta get it put back together!
 
i will see if i can give it another shot tonight maybe. do you have the actual wiring diagram? or the one that another person on the forum made by inspecting his?
 
So I hooked both of the wires with the knots to both positive leads off the board and when I go to hook the other 2 wires up I just get a constant beep. I think I'm going to just have to wait until my buddy does his and go off of that. I'm at a loss right now
 
Never used one

I have never used one but it sounds like most of you do. On this mod what does the vibrating motor do to increase response? and a little off topic but how do you use the tool?
Thanks,
Dave
 
I have never used one but it sounds like most of you do. On this mod what does the vibrating motor do to increase response? and a little off topic but how do you use the tool?
Thanks,
Dave

i liked the response of the vibrating motor insted of the loud beeping from the speaker. pinpointers are used to locate the dirty coins after the plug is cut, many times these coins blend in with the dirt and can take longer to find, the pinpointer speeds up this process with an alert once the tip is close to it. i normally carry my garrett propointer but the centec makes a great backup and costs less than 20 bucks
 
Has anyone had problems using the HF detector in the heat?? If it gets about 100deg. it will not shut up!! Anybody else have this problem?? I havent done any mods to it yet. Another thing, sometimes when it is working right, if I turn the shaft towards the ground ie. upside down it goes off also(no metal around) almost as if something is loose and moving inside...... Any help or ideas???

EDIT- Ok, I tested out my theory.
1. Put a mark on sensitivity knob at the point it wouldnt beep
2. Put the detector in the sun and got it warm
3. Try it out in same spot and it beeps like crazy until I turn sensitivity knob way down.
4. Put on A/C vent to cool it down and now I can turn the sensitivity knob alot higher than in step #1

To sum it all up heat has a very negative effect on this detector, guess I have to bring a cooler with me! :)
Anyone else have this problem with any other brand of PP? Or is it just the HF one? Or just mine lol

I Know this thread is getting old now but reading through it I had the above problems with mine going off all the time when in different positions, after a bit of playing around I found the FERRITE ROD in the coil was loose this affected the field given off making it go off, moving the rod in and out also increased the depth the coil would pick up a key I got it to about 4-5 inches,
then fixed the coil firmly on the rod and put it back, certinly improved the depth, hope this helps someone.
 
Update!

After doing some tests after getting everything soildered together, I found that the vib motor either is always on, or always off. Everything is tight as far as connections go. I noticed that there are 4 small wires parellel to the original location of the probe, that ran inside the probe itself. These wires are bare, and looks like they are just twisted/thrown together from the factory, leading me to believe that its possible to wire all 4 wires together and run a single wire to the probe. This did not work! Next I soildered all the wires individually, using 4 wires total. This did not work! What is the wiring diagram for the probe? Are all 4 wires supposed to be insulated/kept seperate from the others? If grounding was an issue, why didn't centech use insulated wires? I got frustrated and went back to harbor freight to buy a new one. This time around I will leave everything as it is, except for maybe a new switch and vib motor. I thought I could handle this mod, It doesen't look to complex. I think after you attach a longer cable to the probe, it throws the sensitivity for a loop! I have covered everything I know to do to get this to work. Looks cool, just didn't work for me!
 
Hi pulltab
Where do the four wires connect onto the pcb if they are the very thin wires which are uncovered, they go to two coils in the end of the probe and must be connected to the pcb in the same position they were removed so mark each one as they are taken off, it is better to extend the cable or remove them one at a time and connect both ends, but make sure they dont get mixed up. if you have mixed them up, to find which two go together put a multi meter on the ends of two wires if the meter shows a short these two go together, and the other two go together, it wont matter which way they go around as long as they are together in their pairs, if you look at valhad's second photo his two pairs are the blue pair and the green pair. If you read the post by Valhad No 69 above this explains in more detail how to do the mod.
Hope this helped, Cloggy
 
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