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Sovereign GT Mods
Posted by: Critterhunter
Date: February 02, 2010 12:13PM
See the

Re: Sovereign GT Mods
Posted by: deckstar
Date: February 02, 2010 12:27PM
Looking forward to the meter write up, as i truly want to build one.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 11:12AM
Took my GT apart today and have some initial findings and pictures for the various future mods...

I've been thinking about the volt meter mod and when time and money allow I plan to try various meters that should work fine with a Sovereign *so long as they are configured right*. I'll wire a universal/external port to the GT so that various meters can be plugged in using something like flexable spiral wire (phones, cb mikes, etc). Much lighter and more flexable than the coil cable other meters use.

Based on price you could probably buy 3 or 4 styles of volt meters to use and it would still cost less than a commercial meter. This will allow me to use various types of meters based on conditions. For example, an LCD unit for normal hunting, one with glowing numbers for night hunting, and perhaps even an analog needle style unit when I'm in the mood for that. If they need installed in a case something like a plastic chewing tobacco or candy container may be large enough to hold many of these. If not a small plastic project box from Radio Shack should do well.

I'll then be able to velcro a meter any where I like such as on top of the hand grip when the box is mounted on the shaft, or on top of the box or carry bag when hip mounted. I've also been toying with the idea of wearing one on my left wrist like a watch for easy viewing. If somebody wanted to go all out they could even mount a tiny LCD display in a pair of sunglasses. I've seen some in RC use something like this for first person view while flying. Possibilties are endless based on style, size, and type of volt meter used.

One other advantage is being able to unplug it and use a Minelab or Sunray meter in normal fashion. Most people don't use a meter at the beach so it'll be quick to disconnect instead of having to unscrew coil cables. If the meter breaks it'll be just as easy to plug another one in. Coil cables also won't need to modified like some of the other homemade ones require. In the end, it's still going to be cheaper, much less hassle , mess, and weight, and no box or extra cable length wrapped on the shaft putting drag on my swing.



Edited 12 time(s). Last edit at 02/03/2010 11:42AM by Critterhunter.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 01:57PM
Opening up a GT...

Read disclaimer at top of thread. I'm not responsible for any incorrect or even correct information that might damage persons or property. Use at your own risk.

I'm using foam on the top of my work table to try to avoid any dings, dents, or scratches. Be aware that static electricity can damage something. Ground yourself if you are afraid of that. First thing to do is unplug the control box from the coil and remove the battery. Flip the unit upside down and you'll see two screws to the left and right of a sticker. Remove those. The unit should then come apart easily. Don't force anything and don't seperate them far as battery power leads are still attached. You'll see a small white two pin plug where these are connected to the back face of the GT. Unplug this plug and set the lower half aside. This plug should be keyed so that it only plugs in with proper polarity. Just the same, make sure the polarity markings match up before plugging it back in later.

The foil looking material covering the circuit board is an RF shield. Pay close attention to a black wire used to ground the shield in the upper left corner of the picture. It's soldered to a paperclip that's clipped onto the shield. Rather than remove it just remember how it's hitched up in case it comes loose on you while trying to seperate the two shield halves. The two sides wrap over or under each other right in the middle. You'll have to be careful here and take your time to gently seperate them. Note how they are joined together to re-seal the shield later. There's some foam and/or double sided tape used here holding them together. Once you have them gently seperated fold the two halves away from the box so you have a better view of the internals.

You'll notice the large IC chip on the board says "Elite" from the prior Sovereign model. Looking around you'll also see there is a jumper on the board that has a few pins on it and a metal clip. I'm not sure but I think I've heard that jumper is used for single tone operation on older Sovereigns that had a switch hitched up here to change that. You'll also notice a few pots on the board that can be adjusted. One of those might be used for adjusting the tone range up or down the scale. I wouldn't change any of those pots or jumpers unless you know what you are doing. Later I'll try to dig up some threads off the net to explain what they might be used for.

As I thought the back of the coil cable connector is easily accessable for wiring up a meter if you want to do that there. It would probably be the easiest place to tap the source pin(s) for the input voltage used to display the VDI number on a meter. It's also going to be the easiest place to tap power from certain pins to actually run the meter. This is how commerical meters provide the target ID's signal to the meter and power it- through the coil cable. I still have to look into the proper pins for that as well as if the ground for the VDI input is isolated from the main power ground you'd use to actually power the meter. What can change this as well is where you plan to draw power for it from.

If the meter is no more power hungry than say a Minelab meter then it probably would be fine to power it from certain pins on the back of the connector. On the other hand, it might make more sense to draw the power to run the meter from the main battery directly. In which case you'd probably wire it up to the power coming directly from the battery holder, but you'd wan't to complete the circuit right after the ON/OFF switch so the volt meter will also turn off or on when you turn the machine off/on. Based on where the meter gets it's source voltage (here or at the back of the coil connector) this could change how some meters are configured.

Some meters require a certain configuration based on if the input for the VDI display (this is suppoed to be 0 to 2 volts and shows up as a voltage reading on your display) is isolated from the main power and it's ground used to actually run the meter. Until I dig up some more material on the net to figure out all the pinouts for the coil connector as well as check a few things with my multimeter I can't give any more specific information on that. Maybe tonight I'll take some readings.

Originaly I was thinking that tapping power for the meter right after the voltage regulator might be a good idea, providing a stabile (I hear 10.5V but haven't checked for myself yet) power source for the meter to run on. However, soldering to such an area would be well beyond most people's skills without risking serious damage to components on the board. Besides all that, I'm not sure what the current capacity is of the regulator output and you could overheat and destroy a regulator if taxed too much in current. For those reasons I'd only consider either drawing the power to run the meter from either the proper pins on the back of the coil connector or wired somewhere easy right after the ON/OFF switch.

In I hope a more clear summary, with either configuration you'd still probably want to take your input for the number on the VDI display from the back of the coil connector as that's probably the easiest place to solder it up. Depending on where you draw power to run the unit, if it is isolated from the VDI input's power/ground at the coil connector, and what the data sheet for your meter says, all this will determine how the meter is going to have to be configured. Be careful with this because you could easily damage the meter or the machine if it isn't set up properly. I can't give specifics until I've checked a few things on the GT and read over the data sheet for a few meters I might use.



Edited 6 time(s). Last edit at 02/03/2010 02:22PM by Critterhunter.




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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 02:36PM
Lousy site won't let me edit the message anymore so it's still got too much content. Was going to hack most of the bottom half down to something less redundant and to the point. Namely...

In still yet (I hope) clearer detail: Most meters are going to have four pins to hitch up to. Two of these will be +/- for the # on the VDI display (0 to 2 volts output from the GT). The back of the coil connector is going to be the easiest place to tap this. Two other pins on the meter will be the +/- inputs to actualy run the meter. Depending on if the VDI input and the power input are isolated from each other a meter's data sheet may require you to configure the meter properly for either situation. If you don't do this properly you risk damage to the meter or the GT. And, where you decide to draw power for the unit to run on may also alter this. In example, at the coil cable pins or after the on/off switch. I have no idea which is what and if it's going to matter until I take some measurements and dig up a pinout for the cable. There, that's about as simple as I wanted to put it before but can't edit the last message to hack all that out of there. :biggrin:

FInal detail for now on this: Most meters will also require you to configure them for certain source voltage ranges to run on. In other words, the voltage to power it from the coil connector might be a different voltage range than if you were to draw power for the unit right after the on/off switch. I have to take some measurements on that as well. Once you know what the input voltage range will be you'll want to refer to the data sheet for the meter to configure that as well. Usualy configuring this as well as the above isolated/unisolated setups is as easy as adding or removing a jumper on the meter according to it's instructions.



Edited 8 time(s). Last edit at 02/03/2010 02:56PM by Critterhunter.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 03:01PM
Most of this information so far is just an general overview of how meters are configured for input power and the display input. You should be able to apply this information to most meters and follow the data sheets from there. I'll provide the details on what is going on with the internals on the GT later. One other final thing to know about these meters is that they'll usualy require you to configure them for the input voltage range used to display a number on the screen. This might require a few resisters and perhaps a tuning pot (variable resistor) to set up properly. Some electronic supply sites have input parameters on the screen in which you can just enter the voltage (2v) you'll be inputting and they will tell you the proper setup for that.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 03:17PM
Onto the remote pinpoint switch mod for now. I'm going to provide an external port on the GT in which I can plug a remote pinpoint switch to mount on the hand grip somewhere. When hipmounted I can just unplug the switch from the control box and use the stock switch on the GT's faceplate. Mainly the switch I'm interested in modding is the 3 position that has disc iron mask on, disc iron mask off, or the all metal mode. Obviously most people know that so long as the pinpoint switch is set to pinpoint you'll automaticly be put into pinpoint if you throw the other switch into the all metal position. That's where the jumper is going to be needed for this ability to have a remote switch for pinpoint.

You'll notice 3 screws at the top inside of the box holding the face plate on. Remove those. If found it easier to use a vise grip to help torque the screws free because they were pretty tight and don't provide much room for your hand to move around. Be careful with not dropping any tools onto the board and also be real careful with the middle screw. There's a transistor on the board right below it that you have to avoid breaking off the board with a slip of the screwdriver.

Once you have all 3 screws out you've got a choice here. There is one more screw under the circuit board below the middle screw. Rather than go through the hassle of removing the coil connector and unplugging the ribbon connector so I can remove the circuit board and access that screw, I decided to just pry a little on the face plate until the plastic mounting tube it's screwed into snapped off the back of the face plate. I got lucky and it broke clean without putting a hole in the face of the plate or something. It didn't really take all that much force but you might not wish to risk this and go ahead and remove the coil connector/ribbon cable and anything else preventing you from taking the circuit board out to access the screw. I plan to just dab a tiny bit of crazy glue on the end of the mounting tube right before I put the face plate back on. It should stay in place nicely and I'll still be able to unscrew that screw down the road if I want to do it properly. Just don't get any glue inside the hole or it might lock the screw in place forever. Probably don't even need to glue it back and I might not. The face plate should still be snug and it's not like I'm setting drinks on it or something. Remember, if you do decide to force it you don't want the force to snap any wires from the face plate/board that tie them together.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 03, 2010 03:22PM
Look closely that the next two pictures. You can see a little white circle at the lower middle of the face plate. That's where it snapped, and you can see the mounting post on the box right next to it.

You'll see the back of four switches right above the speaker. The one in the upper left corner of that square of four is the all metal, disc iron mask on, disc iron mask off switch. Later when I have more time I'll post a simple schematic of how this switch's 3 posts are configured for any of the 3 modes. You're mainly interested in what you have to do to switch it to all metal.




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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 04, 2010 10:13AM
A few other bits of information for now...

Removing the board to access the fourth screw: If you want to remove that fourth screw that I forced apart on the face plate you wouldn't have to remove the ribbon connector that goes from the face plate to the board. From the looks of it you'd only need to remove the coil connector so it can be moved out of the way and also be lifted out with the board. The connector is secured via a nut on it's backside. Once you remove that nut the coil connector's wires can be guided through an open slit at the top of the control box housing. The board is held in place via two small slots at the top (face plate end) of the board. From the looks of it you'd just lift the board from the coil connecter end of it and it should slide right out of the mounting slits. If you are going to leave on the ribbon cable connected just be cafeful to lift the board and face plate together to not put any stress on the ribbon connector. It should only take a minute to unbolt the coil connector and remove it with the board so you can access that last screw properly. I'd be careful when tightening the nut back on as that plastic on the box doesn't have much meat around it and you don't want to break that by over tightening it later.

More details about the jumpers and pots on the board: I took a minute to look more closely at the board and found that, besides the two tuning pots, there are what looks like 3 seperate jumpers in various places on the board. A 3 pin one is right beside the transistor that's sort'a in the way of the middle face plate screw. When you are trying to take that screw out you can slightly bend this transistor out of the way but be very careful doing that. Another 2 pin jumper exists about an inch away from the 3 pin jumper towards the center of the board. There is also a single pin jumper about an inch from the largest capacitor at the one corner of the board. I'm not sure what any of these pots or jumpers do but when I get around to it I'll see if I can dig anything up off the net.

Where to draw power for the meter: Another additional note about where to draw power from to run the meter. I think the safest place to do that would be from the main battery before the board. By tapping your voltage somewhere here you are drawing current directly from the battery and not from the voltage regulator on the board. I would figure the power supplied to commercial meters through the coil cable might be passing through the regulator. If that's the case a meter that is drawing too much current (more than the commercial meters) might overheat the regulator. Since I don't know how much capacity the regulator(s) have on the board, how much current the board is drawing, and amp draw of the meter would be specific to the meter you are using, it would be safest to draw your power to run the meter at the main battery to bypass all this.

To wire up power for a meter to the main battery: It would be easiest to splice into one of the leads coming from the battery holder and solder the other lead directly after the on/off switch to complete the circuit observing proper polarity. The meter will then turn on and off with the GT's power switch. More than likely the positive lead from the battery is routed through the on/off switch and the negative battery lead is directly going to ground. If that's the case you'd splice your negative input for the volt meter to the negative wire coming from the battery holder, and then your positive would be soldered directly after the on/off switch where the circuit will be completed when the GT is turned on. This is the most likely configuration but make sure it's right. When I get around to taking some readings on the board I'll post specific details/pictures and a simple schematic for drawing power to run the meter from here. I'll also draw up a schematic for drawing power from the coil connector if you plan to do it there. Just be sure of what you're doing if you are proceding without this kind of information and figure out all these things for yourself by taking some readings. And remember, you'll need to know voltage input at where ever you plan to draw the power from and if it's isolated from the 0 to 2 volt input you'll be tapping from the coil connector that shows up as the target # on the VDI display. Based on all that you might need configure your meter properly.



Edited 1 time(s). Last edit at 02/04/2010 10:21AM by Critterhunter.

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 04, 2010 11:03AM
More remote pinpoint info: If you look at the picture above you can see the backs of four switches forming a square just above the speaker. The one in the upper left corner of that square is the disc iron mask on, disc iron mask off, all metal switch. So long as the pinpoint switch on the GT is set to pinpoint the unit will automaticly go into pinpoint mode when that switch is flipped to all metal. You're main concern then would be how this switch is configured for the three settings. Refer to the schematic below which shows the various configurations of the switch in the 3 modes. When I have more time I'll put up another schematic that shows how to properly wire this setup up for the remote pinpoint, complete with a jack on the box where it can be unplugged so you can go back to using the stock switch if say you have the control box hipmounted.



Edited 1 time(s). Last edit at 02/04/2010 11:04AM by Critterhunter.




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Re: Sovereign GT Mods
Posted by: muggsc
Date: February 04, 2010 01:58PM
Thanks Critterhunter. I've been following your posts and I think that you are a true asset to this forum. Keep doing the good stuff. I like this remote switch idea a lot. I'm planning on getting a Sovereign GT as soon as I save up enough money and if Minelab has not started doing the switch by then:lol: I'm definitely going to do it myself.
Thanks again,
Cal



Minelab CTX 3030..and..Minelab Excalibur 11

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 05, 2010 09:29AM
Your welcome. Some of this stuff is covered by other Sovereign owners on various sites. Just trying to bring it all into one place, make it more clear for people in simple steps, and add some of my own ideas as I go along. As far as the remote pinpoint switch goes, all the material on the web I've dug up is dealing with older Sovereigns which I think (? Haven't looked) don't have the same switch configurations to go into various modes like the GT does. I should check into that material more to be sure but I think none of them are dealing with a 3 position switch that the GT uses to go from disc iron mask off, disc iron mask on, and to all metal (pinpoint).

There are several ways you could approach the problem but I think I've got a quick and dirty way to do it with the parts I have on hand in my junk box. I'll throw up a schematic (actually it'll be more of a pictorial) in a little bit here. It for sure would probably be the easiest way, should work fine, and won't require me to make a run to the electronics part store.

Going out to have a smoke and then I'll draw something up real quick here to post...

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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 05, 2010 11:55AM
Try this...Better check my work as I just through this pictorial together quick for a quick, dirty, and easy remote switch to throw unit into pinpoint, all metal fixed, or all metal track (depending on what you have that switch set at on the GT). What you'd do is cut the right post halfway between the switch and the circuit board using a dremel or small snips (toe clippers work well). Bend these two ends away from each other a bit to insure they will never make direct contact again. Now solder a wire from the switch side here to a jack you install on the box. Another lead from jack would go to the post end on the circuit board side where you cut it. When soldering these protect the circuit board below the switch with paper or something in case you drop some solder. Try to work quick and solder only to the very cut end of both to avoid excess heat transfer to the switch or board. If your not real experienced with soldering remember flux works wonders to clean/prep the solder conection.

Anyway, the jack will be normaly closed (n/c) when there is no plug installed in it so the circuit and GT switch will work as normal without the remote switch plugged in. Once you plug in the plug for the remote switch the jack will go to being an open circuit (n/o). The circuit is routed through the jack down the wire and to the remote pinpoint switch. The circuit will stop there unless the switch is closed. Several types of switches can be used here. The type that won't close unless constantly held down, the type that will close or open with every push (staying in that mode until pushed again), or you could even use a normal toggle switch such as Whites use if you like them trigger style. I'd probably opt for a waterproof button style that will stay open or closed until pressed again to switch and hold modes.

Here's whats happening...With no plug GT switch works as normal. With remote switch plugged into GT switch for disc iron off and disc iron on will work as normal (but with no ability to use the remote switch to throw it into all metal unless remote switch is closed). If you throw the GT into all metal and the switch isn't close the GT will still think it's in disc iron on mode. This is the way you want to hunt, with the GT set at all metal. With remote switch open the GT will operated in disc iron mask on mode. Press the remote switch and it's now in all metal mode. Depending on where all metal mode switch is set (pinpoint, fixed, or track), the GT will now go into that mode of operation. Press the remote switch again and you're back to disc iron on. For this reason this remote switch can be useful for doing reverse discrimination even if you don't need pinpoint. Hunt while in all metal tracked or fixed and then press the button to quickly check the target in discrimination.

Later I'll wire this thing up and make sure it's working. I'll dig up the part #s from Radio Shack and throw up a real schematic with the proper wiring of the jack, plug, and switch including any other details needed. Pictures as well. This is just a way to cheat the GT into doing something without getting more complex. For instance, you could have a remote switch that would have all 3 operating modes, bypassing the GTs. More complex then needed for most people, though. How many people need to switch from disc iron off to disc iron on and all metal remotely. Most use disc iron on and all metal (pinpoint) modes.



Edited 1 time(s). Last edit at 02/05/2010 12:17PM by Critterhunter.




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Re: Sovereign GT Mods
Posted by: Critterhunter
Date: February 05, 2010 12:34PM
Once again site prevents me from editing down the message. I'll have to start writing this stuff in word so it'll be in final format before posting. A little confusing but I think most people get it. There is a misprint in the picture towards the bottom where it says "unit will go from all disc iron on". Should just say "unit will go from disc iron on". If you have any questions or see something wrong let me know. Haven't thought it through over a smoke and a cup of joe to make sure my logic is right...

Re: Sovereign GT Mods
Posted by: razzz0
Date: February 05, 2010 02:53PM
Critterhunter, why don't you run a parallel remote switch to the main switch.You can leave the main switch in the middle and use three functions on the remote if you want to by using stereo jack and plug.

I am working on meter also.It is better Ida to tap on the unit's power then the coil's but I do not know if we need voltage regulator for voltmeter or not yet.
I have original sov meter shematics if you need it. My progress is very slow since I am very busy with other thing.

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