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Bush said:
Alternative cheap coil option for SDC2300.
Compliments to Auman for placing me in the right direction.
The coil seems to operate as well as the standard 8``.
A little tricky die grinding the bracket supports for fitting the detector shaft.
`i` used a rotary chainsaw sharpener to thin out the walls and will build out the outer sides with glued plastic washers to re-enforce the bracket.
Pic of the F158 coil.

https://www.prospectingaustralia.com/forum/img/member-images/6815/1586461861_f158_coil.jpg

Why? The F1A4 was supposed to pick up a grenade sized item at 600mm in dry sand. I'm sure the SDC would be able to do that. It's like owning a Bugatti Veyron and putting a pair of Shoo Roos on it. Pointless.

Cheers

Doug
 
Jaros said:
Who "owns" a Bugatti Veyron. I watched the Top Gun episode when they ran it out to top speed----sheeeezzzzuz!! and I thought doing 180 kph in my old Statesman V8 was fast. It did float a bit and vibrated badly on braking but - what a trip.

Back on subject please. :lol: :lol: :lol:

Cheers

Doug
 
`i` liked the car trip story Jaros sounds great.
Back to the coil though.
Each to their own.
It works i can tell you that.
It`s picking up 15 x 15 mm foil @ 3`` to 4``.
20 x 20mm foil @ 12``
No replies to the foil test request asked previously i guess we wouldn`t want to compare.
See if your SDC2300 will detect a 10 x 10 mm piece of Alfoil or what it can go down to in size.
It` all very well stating pointless Rockhunter62 but you have travel cost to get out to Woop Woop & have traveled a long way & only relying on one coil in the event of it braking down.
A back up coil seems a good idea to me.
I guess if you have a spare $500 to $600 bucks for Minelab 8`` original or the Coilteks for a back up then alternatives are not needed.
Each to their own.
Pessimists Ignoramuses. ;)
 
Bush said:
`i` liked the car trip story Jaros sounds great.
Back to the coil though.
Each to their own.
It works i can tell you that.
It`s picking up 15 x 15 mm foil @ 3`` to 4``.
20 x 20mm foil @ 12``
No replies to the foil test request asked previously i guess we wouldn`t want to compare.
See if your SDC2300 will detect a 10 x 10 mm piece of Alfoil or what it can go down to in size.
It` all very well stating pointless Rockhunter62 but you have travel cost to get out to Woop Woop & have traveled a long way & only relying on one coil in the event of it braking down.
A back up coil seems a good idea to me.
I guess if you have a spare $500 to $600 bucks for Minelab 8`` original or the Coilteks for a back up then alternatives are not needed.
Each to their own.
Pessimists Ignoramuses. ;)

Hi Bush, using alfoil as a test piece will only give you an idea of comparison between the two coils. Alfoil does give off a big signal. Grab one of your nuggets at about 1 gram and try that. This will give you a better idea of how your F158 coil detects your targets. Foil and gold are different signals.
As for a back up coil if my other coil breaks, well, the SDC is the back up for when the GPZ doesn't want to work. Hasn't happened yet though and then I still have the Gold Monster to play with as well.
As for the name calling, I'd prefer to hear from the dog.

Cheers

Doug
 
Bush, I do not own a 2300, but have seen pin head size gold picked up by these machines.

I think its best to do a side by side test ( with another 2300) in the Goldfields using the same setup.

A Friend calls this very small Gold niggits ( not nuggets), the vid below shows a nugget its not small enough to be called a niggit in his criteria.

https://www.youtube.com/watch?v=p3J1IOiVY0M
 
PeterInSa said:
Bush, I do not own a 2300, but have seen pin head size gold picked up by these machines.

I think its best to do a side by side test ( with another 2300) in the Goldfields using the same setup.

A Friend calls this very small Gold niggits ( not nuggets), the vid below shows a nugget its not small enough to be called a niggit in his criteria.

https://www.youtube.com/watch?v=p3J1IOiVY0M

I would agree with you there Peter but each detector can be slightly different in performance. Changing the coil on the one detector would give a better result. :Y:

Cheers

Doug
 
Bush said:
Cheers - AuMan,
`i` really appreciate the circuitry tips..
Had a feeling that the two carbon shield plates needed to be isolated from each other around the coil edge regardless that their connections merge together up the track.
My feelings on the coated cardboard is Fubar ( tango & cash ) F-up beyond all recognition.
It`s hard to believe the original carbon coatings are so thin including the cardboard.
Earlier `i` mentioned `i`ve ground up filtration carbon for the PVA carbon glue mix.
New cardboard is cut / folded and ready to go.
In testing the mix the glue seems tobe restricting the carbons conductivity.
Which makes me think activated carbon from the Brewery shop could be the go.
It dries sticky from memory and may add more of the grounded filtration powder to it.
`i` heard on the grape vine that Stainless Steel Mesh may work as a Faraday shield.
but i`m not shore 4 shore.
Could possibly introduce it between the carbon coats.
304 or 316 marine grade and wondering if it`s Austentic ??
Sort of makes me wonder if any other non -magnetic plate-ing could be used which could ``Possibly Improve `` the Coil Performance.
Doubt it though MineLab Techno`s Researchers would have done The Calc`s.

The SDC Curly Cable is FUBAR too.
Previously i did tried heat on the outter sheathing to straighten it `but` failed as it is the inner white cable that keeps it sprung & curly.
Coiltec cable `i` now realize is two core multi strand wire both have shielding and an additional insulation coverings. .
The SDC cable is quit different in it`s composition ,number of strands , AWG and sizes.
One thing i can do is use the Coiltec cable joining the 2 desperate shielding wires together to mimic the SDC cable.
`but` A BIG BUT on what outcomes will occur with both wires shielded by the same wire.

Hopefully an Enthusiasts on P/A with some knowledge could place some Potentials Outcomes could input here . ????
Pic attached.
https://www.prospectingaustralia.com/forum/img/member-images/6815/1560725798_20190617_083703.jpg

These outer cables breaking down is common. There are two fixes for this.

(1) Cover the old cable with 'heat shrink tubing'. You have to remove the plug.

(2) Obviously made that way so you have to 'Buy a new curly cord'.

The heat shrink is a good fix providing you take care rejoining the plug to the right spot.
 
Rockhunter62 said:
Bush said:
Alternative cheap coil option for SDC2300.
Compliments to Auman for placing me in the right direction.
The coil seems to operate as well as the standard 8``.
A little tricky die grinding the bracket supports for fitting the detector shaft.
`i` used a rotary chainsaw sharpener to thin out the walls and will build out the outer sides with glued plastic washers to re-enforce the bracket.
Pic of the F158 coil.

https://www.prospectingaustralia.com/forum/img/member-images/6815/1586461861_f158_coil.jpg

Why? The F1A4 was supposed to pick up a grenade sized item at 600mm in dry sand. I'm sure the SDC would be able to do that. It's like owning a Bugatti Veyron and putting a pair of Shoo Roos on it. Pointless.

Cheers

Doug
Err, no the F1A4 was meant to pick up small a landmine firing pin at 6", which it could do very well.
When modified, the F1A4 can even give the sdc a run for it's money. Smallest piece I have found with an F1 is 0.01g, even managed to get that one on video.
The old F1A4 coil has very similar characteristics to the SDC coil, which is very close to a lot of aftermarket coils. The SDC does need very tight spec'd coils. If they are too slow to settle after the transmit pulse, then you will have problems, hence why I suggested the the F1 coil to Bush, which he seems to have running nicely.

Cheers Mick
 
AuMan said:
Rockhunter62 said:
Bush said:
Alternative cheap coil option for SDC2300.
Compliments to Auman for placing me in the right direction.
The coil seems to operate as well as the standard 8``.
A little tricky die grinding the bracket supports for fitting the detector shaft.
`i` used a rotary chainsaw sharpener to thin out the walls and will build out the outer sides with glued plastic washers to re-enforce the bracket.
Pic of the F158 coil.

https://www.prospectingaustralia.com/forum/img/member-images/6815/1586461861_f158_coil.jpg

Why? The F1A4 was supposed to pick up a grenade sized item at 600mm in dry sand. I'm sure the SDC would be able to do that. It's like owning a Bugatti Veyron and putting a pair of Shoo Roos on it. Pointless.

Cheers

Doug
Err, no the F1A4 was meant to pick up small a landmine firing pin at 6", which it could do very well.
When modified, the F1A4 can even give the sdc a run for it's money. Smallest piece I have found with an F1 is 0.01g, even managed to get that one on video.
The old F1A4 coil has very similar characteristics to the SDC coil, which is very close to a lot of aftermarket coils. The SDC does need very tight spec'd coils. If they are too slow to settle after the transmit pulse, then you will have problems, hence why I suggested the the F1 coil to Bush, which he seems to have running nicely.

Cheers Mick

Err Mick,

The F1A4 could also pick up the firing pin of a landmine at 6" as per the test piece supplied with the detector. Having used this detector in the field in South East Asia I am quite versed in what this detector can do. This detector has saved my life several times unlike the way people are using this detector to find gold. A piece of gold has never tried to kill me yet.

I am sorry that I only quoted the maximum depth scenario and not the minimum. I am also sorry that I never quoted my qualifications with mine detectors.

One thing that I have no time for is people who do not think before they post. If you done your research, you should have seen that I have used this detector in the real world.

Next time, think before you post. I can not stand lab rats spruking their self opionated bs to try and sell their own work.

You didn't even try to introduce yourself into the forum before trying to say how good your are.

I apologize to everyone for my reply and if I have offended you AuMan, get out in the real world and thank Minelab for supplying you with a hobby.

Cheers

Doug
 
Rockhunter62 said:
AuMan said:
Rockhunter62 said:
Bush said:
Alternative cheap coil option for SDC2300.
Compliments to Auman for placing me in the right direction.
The coil seems to operate as well as the standard 8``.
A little tricky die grinding the bracket supports for fitting the detector shaft.
`i` used a rotary chainsaw sharpener to thin out the walls and will build out the outer sides with glued plastic washers to re-enforce the bracket.
Pic of the F158 coil.

https://www.prospectingaustralia.com/forum/img/member-images/6815/1586461861_f158_coil.jpg

Why? The F1A4 was supposed to pick up a grenade sized item at 600mm in dry sand. I'm sure the SDC would be able to do that. It's like owning a Bugatti Veyron and putting a pair of Shoo Roos on it. Pointless.

Cheers

Doug
Err, no the F1A4 was meant to pick up small a landmine firing pin at 6", which it could do very well.
When modified, the F1A4 can even give the sdc a run for it's money. Smallest piece I have found with an F1 is 0.01g, even managed to get that one on video.
The old F1A4 coil has very similar characteristics to the SDC coil, which is very close to a lot of aftermarket coils. The SDC does need very tight spec'd coils. If they are too slow to settle after the transmit pulse, then you will have problems, hence why I suggested the the F1 coil to Bush, which he seems to have running nicely.

Cheers Mick

Err Mick,

The F1A4 could also pick up the firing pin of a landmine at 6" as per the test piece supplied with the detector. Having used this detector in the field in South East Asia I am quite versed in what this detector can do. This detector has saved my life several times unlike the way people are using this detector to find gold. A piece of gold has never tried to kill me yet.

I am sorry that I only quoted the maximum depth scenario and not the minimum. I am also sorry that I never quoted my qualifications with mine detectors.

One thing that I have no time for is people who do not think before they post. If you done your research, you should have seen that I have used this detector in the real world.

Next time, think before you post. I can not stand lab rats spruking their self opionated bs to try and sell their own work.

You didn't even try to introduce yourself into the forum before trying to say how good your are.

I apologize to everyone for my reply and if I have offended you AuMan, get out in the real world and thank Minelab for supplying you with a hobby.

Cheers

Doug
Apologies Doug, as I think I may have misread/misinterpreted your post. It seemed you were having a dig at Bush for having a go and posting about it.
I don't have time to do a full history search on everyone I post/reply to.
My point about the small size that the standard F1 coil can detect was merely to show that the coil itself is capable of doing what the SDC coil can.

I did not try to sell anything and could not care less to come onto forums to sell stuff. I just share what I know from my experience both in the lab and field, though I have never been on a mine field. You have my respect.
I don't know which part you consider BS.

Cheers Mick
 
Hey Folks ,
To the Members on Prospecting Australia that have contributed to this Topic.
Initially create by Grubstake .
Invited by Jembaicumbene.
My appreciation goes out to all those that have been supportive.
Many Thanks to Prospecting Australia for supplying This Great Web Site.
Staying Positive in these most difficult times will be a Virtue.
Respect and Discipline will be what is needed to over come this Global Disaster.
This modded SDC 2300 topic is in it`s Final Phase.
Stay Well. Eat Well.
Be Conscious of your Viral Surroundings.

1586630502_composer.jpg


1st pic Deleted -violence not needed thanks.
 
News Flash.
F1A4 coil detects 0.034 gram of rusty iron @ 3`` in Highly Mineralized Ground.
Unit ran for 4 hours in settings 5 maxed out without any issues. SDC2300 purred like a kitten.
F1A4 good alternative coil option.
Myth Busted.
Congrats to Auman @ Detectronics Australia.
 
Only The Brave Dare Where Angles Fear to Walk.

SDC2300 Headphone Chassis Socket 1/4`` ( 6.35mm) Installed .with auxiliary external speaker on / off switch.
Original existing 6 mini pin headphone chassis socket remains in place and operational.
Using the existing position to replace the mini 6 pin socket seemed tobe a No Go.
The supplied Jaycar unit was questionable to fit and the 1/4`` straight pin was to long to insert blocked by the units plastic concave casing ( a possible 90* degree pin plug may have worked.)
So i sort another position near the right hand front of the SDC.
As you will see in the pics where i mounted this little black box i now would have chosen a spot about 1`` further back as the clearance tolerances would have been just a little easier.

Had a little trouble as the Jaycar 1/4`` chassis socket supplied for the external speaker deactivator terminals for the 1/4`` stereo plug is a ( in -off ).
What is needed is a ( in - on ) when the headphone lead plug is inserted into the chassis plug housing to defuse and deactivate the external speaker.
Jaycar PS0182 possibly may have worked.
So in Hindsight ( after the fact ) and not wanting to travel another 150 k/ms round trip to Jaycar i decided to adopt Mr Money Boxes approach to the solution.
Link here with : https://www.prospectingaustralia.com/forum/viewtopic.php?id=28366
My wiring image.
1613730804_20210219_174040.jpg


Only difference is `i` spliced into the existing cables and incorporated the white wire as i found it had a signal response when testing the cables.
Presuming the SDC is a mono signal sound system `i` used the white wire as a secondary mono connection onto the stereo 1/4``pin plug.
Red Common. White & Black / Left & Right as in a typical stereo lead set up.
New 1/4`` Jack outlet image.
1613731018_20210219_174122.jpg


The little ( on / off ) switch `i` found in my box of tricks `i` mounted on the left in a recess near the handle which is near in perfect position and size for lesser snags in the scrub.
The exit point for the head phone lead jack is not the most desired position but if trouble occurs with scrub hook ups i`ll just change the 1/4`` pin to a right angle connector.
New External Speaker De-activator Switch image.
1613731150_20210219_174205.jpg


Another issue i had was the external speaker twin yellow wires snapped from excess movement opening and closing the unit covers to many times testing that everything fitted snug.
The wires are very short and of solid single core which go brittle with to many movements so i replaced them with multi -strand wire.

Only Question arises now is What is the Yellow cable wire used for or potentially there for.
So i installed the set up with that single yellow wire long enough and conductivity capped / isolated in the event it maybe needed at some stage.
Everything at present seems tobe working fine on the bench .
`i` just need to insulate some of the exposed soldiers on the chassis plug terminals as we all know how sensitive these SDC`s are .
Assemble the unit back together for full load testing.
Further More ;
`i` would not recommend anyone attempting this hazardous modification that could lead to permanent damage to an expensive Machine.
 
The 3rd wire (white?) is possibly the built in speaker on/off wire.
I.e. in a normal Minelab audio set up using normally wired stereo (TRS) headphones the sleeve connection will turn any in built speaker off (or in the case of the GPX battery the amp) when headphones are inserted.
For the GPX battery an external speaker needs to be wired to tip & ring only for the amp to cut in (picture below) or on other detectors once the headphones are removed (no sleeve connection) the speaker turns on.
1613796463_20210220_154712.jpg


I wouldn't be surprised if the SDC plug has this 3rd wire to deactivate the external speaker when you plug the headphones in or activate it when they are removed.
The external switch probably isn't required when wired correctly?
 
In Mr Moneyboxes Post he mentioned in his conversion that two of the terminals were bridged which now makes me think this is how the SDC headphones receive both left & right signals initially through the terminal at the chassis then branching out to from the bridge terminals to the Jack wires of headphone speakers of which i now assume is a split mono signal L/R.
Also the Red wire seemed tobe ( the Common ) or lets say ( the negative maybe ) of which makes me think that the SDC is a Positive Grounded Earth set-up not Negative ``but`` again i`m only guessing as both wires branch back to the red to return the signal.

Realizing now that when i had the sdc mini 6 pin chassis plug out i should have examined it properly as i would have noticed which terminals were bridged.
Side tracked then i was as i was disgruntled & dis-heartened when i noticed that the GPX straight pin plug would not insert had i followed through with the new 1/4`` chassis plug install in it`s original position.

I think Mabasko you most likely are correct relating to the White wire and the Green wire is what Minelab uses to defuses the external speaker yet why i chose to use the White one is I had a choice of using the Blue or White wire to defuse the external speaker both worked but chose the Blue as it had lesser voltage just thinking that was a safer path to follow.
The White wire also had signal response so again presuming it was a headphone speaker wire and because the Headphone cables are Red / White & Black `i` Assumed the SDC could be a Stereo out put.

"With the GPX external speaker wiring as you mentioned Mabasko ```Quote ``` (( For the GPX battery an external speaker needs to be wired to tip & ring ONLY for the amp to cut in.))

This may explain why when i tried the GPX external speaker on the SDC earlier in the new chassis plug it ( Did Not Work ) and again only guessing then it may have been faulty or of a different Ohms or Voltage.
So Excellent Mabasko on Posting that info i may need to rehash the wiring to achieve this result.

In relation to the on / off switch regardless that it may not be needed i agree with Moneybox that being able to flick the switch & to scan the divots without the headphones on or pulling out the lead jack could be a good advantage.

The Yellow cable has got plenty of Power but does not give any signal to the speakers. This one has me BAFFLED and i can only presume it is a power booster wire. ?

The external speaker cuts out when cross Green to White or Green to Blue and not including the speaker wires of which i believe do.

Nothing occurs to the external speaker crossing Yellow to Blue which seems strange as there is 5.64 volt in that polarity.
+ Yellow to - Green = 8.63 volt in that polarity.
+ Blue to - Green = 3.18 volt `` `` `` `` `` ``` ``
+ Yellow to - Blue = 5.64 volt.`` `` `` `` `` `` `` ``
Excuse me too that i`m multi lingual in the language of electricity so my AC & DC terminology does get a little mixed up at times Earths / Grounds or Commons hopefully is not too confusing.
Interesting Stuff.
Cheers.
 
Another thought on the Yellow and Blue wires that seem tobe spares on the sdc.
Sometimes manufactures of electrical products include such extras to assist with their testing and monitoring to confirm everything is OK prior to distribution.
They could also be placed there as a back up circuit power source in the event of potential updated accessories or additional equipment.
Also there are 4 x 1.2 volt batteries that power the SDC which equals to a 4.8 volt DC power supply .
To have the volt meter reading of the Yellow to - Green of 8.63 or 8.64 volt slightly variable certainly indicates the presence of dual capacitors or maybe some kind of inductor.
For what reason this higher voltage on this particular Yellow wire is very unclear and remains a mystery in my mind.
Some electronic wizard on P/A would have a better idea than myself on this subject and it would be great to verify these theories.
Have a Great Day. :Y:
 
Yes the GPX detectors have a diagnostic line thru the quick track button socket so wouldn't surprise me if the SDC has similar but thru the headphone socket.
The F3 Compact (which the SDC is based on) can be hooked up to a programming cable, when using configuration software to customise volume & sensitivity settings, thru the headphone socket.

Minelab detectors are also internally voltage regulated. I'm not sure what they use to do this but it would need to be some type of step up voltage regulator or boost converter I would assume i.e. they take a lower unstable/dropping battery supplied voltage & regulate/boost it to a higher, more stable voltage. This will ensure that detector performance remains consistent as the charge state of the batteries begins to reduce.
Some will say to keep your batteries fully charged, top up at lunchtime etc. but it's not really necessary as the performance should be consistent right down until the low voltage warning comes on. All topping up does is prolong the time to low voltage warning &/or shutdown.
 
The Plot Thickens.
Just did some more tests the ohms readings of the GPX external speaker is the same as the SDC external speaker so they are compatible at 0.08 ohms.
One significant difference is the voltage output from the GPX 1/4`` socket is 2.24 volt basically L& R sides of each stereo terminal individually crossed to the red common.
The SDC out put here was 0.01 to 0.02 volts a very different regardless that the SDC internal speaker is loud and clear.
The GPX external speaker attached to the sdc has a very low volume when the new switch is set to the new 1/4`` outlet.
The GPX external speaker is loud when the sdc internal speaker is on both speakers producing loud volume signal response at the same time.
It would seem possible to achieve the 1/4`` outlet to run the GPX external speaker on the sdc whether that is really any advantage i guess would be a personal choice.
Seems like to remove the white wire from the new stereo chassis plug and attach it to the new switch could be the sensible answer and disregard the blue and yellow wires as Moneybox did.
Either that or run the unit that is working for an extensive period of time an see if there are any significant changes.
I`m not shore what is going to fry first my head or this sdc . Probably Both. :8
 

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