baracuda project questions

[satdaveuk]

Hi
Proberly been asked this before desided to put this project together as i got most of the bits apart from the transistors which are two parts ive not got in stock, would i get away with say bf245c,b, or a,.?
Also before building is the non motion pinpointing mode working now on the latest circuit release ? As i want to only use it for a pinpointer without motion.

Regards
Dave

[sinclairuser]

i dont think the q5 problem has been solved dave no one seems interested my own personal view is the piecemeal approach to components employed in this project is the reason this feature does not work and the only way to remedy this situation is to build the barra exactly as the original
from what i understand only alexismex is playing with this but as i said in the barra thead while this is unknown our barras will never be finished! the barra seems quite tolerant in terms of trannys so maybe what you have may work but my own feeling on this is until this project is built with exact components this part of the schematic will be unknown and yes that means tip127 and 9v though some on this forum will argue the toss forever on this issue
thanks aly x
p.s. followed your posts on graphite shielding and thanks works a treat!

[satdaveuk]

Thanks for your honest feedback sinclair ive got the TIP127 in stock from years ago which is handy because never thought Id ever find a use for them anymore, if my memory serves me correct they are a darlington pnp type device, but of course will check that out, Using 9v is perfect for me.
Now the way it stands I made the PCB early this year from the lay files.
So firstly is the hand drawn circuit at the begining of the project original or is it a draft made up before the lay files were posted.
Secondly if it is drafted from the original Baracuda has anyone here built it, got it up and running fully functional all bells and whisels including non motion mode.

Regards

Dave

[sinclairuser]

hi ive just gone into the barra thread to find those lay files satdaveuk mentioned and noticed something the original board photo alexismex posted clearly shows no conections were made on the points for the switch maybe it never worked correctly and as we say we are flogging a dead horse? also where do the led wires go?

[satdaveuk]

yeh your right Sinclair i presume your meaning switch 1 no wires at all.
Tell you what im going to do before anything else, will post on a couple of sites asking if anyone still ownes a Baracuda and if there is actually a pinpoint mode because as you correctly said we could be looking for a function that was never implemented on the Baracuda, which if so will close a chapter for once and all.

Regards
Dave

[satdaveuk]

After reading many reviews on the Barracuda incl the one by Andy Sabisch who spent many hours using the machine. The detector never had pinpoint mode installed infact that was the only downside of the detector, its always been a problem.
It only had two external controls one was the on/off sense the other threshold.
What it did have however was discrimination between coloured and non coloured metals that actually worked, wiping out iron nails.
This was not a just put together machine to hit the market the designer spent hundreds of hours getting it right.
Made by Anchor electronics in 1991 which no longer is.
So by what ive read we are infact flogging a dead horse far as pinpoint mode but certainly worth the build but with components near to Anchor electronics spec as possible for it to work correctly.
Interestingly enough alot is mentioned here on are forum regarding the TIP127 far as getting some discrimination, maybe we need to look further into other components that have been substituted.
Also worth taking note it was manufactured and marketed with a 8" coil, that also proberly comes into the equasion as its seeing less ground.
Anyways im going to go ahead with this project because I cant go forward anymore without something in front of me, been a hands on sort of engineer.
This project the way it stands is going to be a good learning platform for me, i just hope its not going to get abandoned like so many other projects on here as it needs and deserves perfecting.

Will be a good idea now to carry on with this thread as a part2 to make it less confusing for other interested partys, so as i progress will post here

Regards
Dave

[dfbowers]

After reading many reviews on the Barracuda incl the one by Andy Sabisch who spent many hours using the machine. The detector never had pinpoint mode installed infact that was the only downside of the detector, its always been a problem.
It only had two external controls one was the on/off sense the other threshold.
What it did have however was discrimination between coloured and non coloured metals that actually worked, wiping out iron nails.
This was not a just put together machine to hit the market the designer spent hundreds of hours getting it right.
Made by Anchor electronics in 1991 which no longer is.
So by what ive read we are infact flogging a dead horse far as pinpoint mode but certainly worth the build but with components near to Anchor electronics spec as possible for it to work correctly.
Interestingly enough alot is mentioned here on are forum regarding the TIP127 far as getting some discrimination, maybe we need to look further into other components that have been substituted.
Also worth taking note it was manufactured and marketed with a 8" coil, that also proberly comes into the equasion as its seeing less ground.
Anyways im going to go ahead with this project because I cant go forward anymore without something in front of me, been a hands on sort of engineer.
This project the way it stands is going to be a good learning platform for me, i just hope its not going to get abandoned like so many other projects on here as it needs and deserves perfecting.

Will be a good idea now to carry on with this thread as a part2 to make it less confusing for other interested partys, so as i progress will post here

Regards
Dave

Dave,

Go for it! It's a great detector as far as PIs go. I used mine a few weeks ago at the beach and it performed flawlessly, even in salt water. I didn't have to touch the threshold adjustment at all once I tuned it. I found 3 pieces of junk jewelry at pretty good depths, plus a handful of coins in a few days. I settled on a 9" coil as it seems to hit harder on coin sized object within detection range.

As far a discrimination goes, I just don't see how it was designed it the Baracuda. It's just a PI, not that radically different from the Surf PI. I did however learn to distinguish between ferrous/nonferrous but it's just a characteristic of a mono loop and the SAT.

http://www.youtube.com/watch?v=PVxLw...9&feature=plcp

I will have to test my Surf PI to see if I can do the same thing.

Don

[sinclairuser]

Will be a good idea now to carry on with this thread as a part2 to make it less confusing for other interested partys, so as i progress will post here

Regards
Dave

ok dave though im more confused than ever i kind of wondered if the combination of tip127 and q5 etc was to do with the reported iron rejection however don in above post says he has learned iron identification but dons barra(if i read his post in the barra thread right) does not have the q5 components installed as he was the one who confirmed to silverdog that removing those components was the easy way to make the kit stable!
but i am going to get another barra kit when silverdog returns off holiday and alter components to original spec then fit this in my working barra as like you that unknown part of the schematic really bothers me(probably as much as it bothers you!)
thanks ally x
p.s. dont know how many tip 127s you have but i'd be interested buying one off you seen as we are both in the uk(i have found a supply but i dont want to order 5 when i only want one!)

[satdaveuk]

Thanks for the imformation Don, its worth reading Andy Sabish report hes well respected and has spent many hours with the detector and was very impressed to say the least, unless he got a back hander from Anchor
Im hoping to get feed back from other forums from people who own and still use them to set the record stright. Q5 could be the key to it, at the very least would be nice to know what it really suposed to do, if infact if its needed at all, but im sure it wouldnt have just been plonked in there for nothing.
By all accounts iron such as nails etc should give a washed out type of sound while on the other hand coloured metals such as gold and silver should be a sharp crystal clear cut sound.
Sinclair I will look to see what ive got in stock over the weekend as im busy tomorow with work, im sure i got a few in the workshop, if so will post you one, if not will order some.
The original Barracuda you have, does it work? is it made by anchor or was it a kit you made up?

Regards

Dave

[6666]

Interesting video thanks for it Don

[satdaveuk]

Hi
Don all along has said he gets some sort of discrimination excluding q5 but the way ive read different posts from users of the original there getting a positive ovious difference between coloured/non coloured just by a few sweeps of the coil .
Anyway what ive done is ordered all transistors as listed from the original artical on this forum which may i add is riddled with errors and confusion but ive sorted it out and shall include Q5. all manufactured by fairchilds for common leadouts to stop confusion.
transistors are as follows:
Q1 = TIP127 Darlington PNP
Q2= 2N2222
Q3= 2N5485 N Channel J Fet
Q4= MPF102 N Channel J Fet
Q5= MPF102
Q6= MPSA13 Darlington
Q7= MPF 102
Q3/Q4 are not suposed to be matched although they are both N channel J fets they are different specs for a purpose and we need to find out what that purpose was.
Can I ask is there anyone here actually built this project using the transistors ive listed?
The reason why Im asking is because its ringing alarm bells and reminds me of the Minipulse3 project where as the sucess of the project was using the correct spec components, not looking at spec sheets and desiding it was close enough, because if thats done throughout a project you can quite easily end up with things not working as they should or could do.
Im all for modifications and improving things but it makes sense to get these projects working as they should do in the first place, otherwise you dont know if your looking for a design fault or a man made one or if infact there was one in the first place.
After saying all that ill proberly build mine and it wont work lol

Kind regards
Dave

[bernte_one]

disc

hello

disc is not a secret of pcb components
you can produce a working metal separator (not fully a disc)
with a special coil

i have tested and it works
for example bottle cap ist nearly rejected while coin (my probe was a ten reichspfennig pieces) is accepted till 5cm away from coil at more distance only coin comes with signal no more signal from cap

was able to set the delay trimmer to minimum (ccw) for best distance

i think secret is a good damped coil with low c
but disadvantage was that the overall depth was lower as my other normal litz coils which can separate

do you want to know which type of coil i used

i was coil from delta pulse which is delivered with the delta pulse demonte kit from turkey
the easy one on three layers of network cable type connected lines in serie
the easy one which is only covered with tape
http://www.teknolojiekibi.com/images...demontekit.gif

i gues when i remove installed 5w resistor (dont know the resistance at moment) i could raise also detecting distance

so nice day i hope you have some task for today now

[satdaveuk]

Thanks bernte
Funny you saying about minium on your delay because if you start canceling out bottle caps by adjusting delay with the original Barracuda you will reduce depth by quite alot but also more importanly you wont see Gold, and thats what the manufactures of the Barracuda avoided, and advised to only adjust that in extream circumstances where there was heavly contaminated soils or sand.
Try it out and see if im correct because we are all learning something here.

Thanks also for your video Don its nice addition to have on here for all to see.

Regards

Dave

[sinclairuser]

hi dave/all
my barra is a silverdog kit rev2 built as thread spec without q5 ect
the coils ive wound are 5.5 inch 450 uh/ .9ohms(unshielded) and a 11 inch eliptical 448uh/ 2ohms(shielded satdaveuk style)
offset set at 0v
delay adjusted to detect my 9ct gold wedding band WILL NOT DETECT 14,18 OR 22CT GOLD WITH ANY OF MY COILS OR SETTINGS! ALSO HAVE BULLION 24CT GOLD AND SILVER LEAF BUT ONLY DETECTS THE SILVER (JUST) acually thats a question for you dave could we use gold leaf as a shielding?
but it works so i thought build original spec board and replace and see the difference
as for that tip 127 ok i will buy five if i had to but your old stock might be nearer to original ive seen before new modern replacement components that are supposed to be the same(even same markings) that were off so old unused tip127s make sense(i know tip127 is obsolete and they are probably all old stock but you never know) if im doing this im doing it right!
thanks ally x
p.s. i have not touched damping resistor as im waiting for a scope radio jumble sale is mid sept (why pay thruogh the nose when i can get one for next to nowt!)
oh and yes good vid don x

[satdaveuk]

Have found a couple of TIP127 which I want to hang on to but theres other draws need going through, will look next week.
Gold leaf far as screening may well do the job well, but never tryed it, also how robust is it? Give it ago and let us know.
You will find almost any detector will pick up 9ct gold because of its impuritiy, So if your not detecting 22ct gold then it means your not detecting gold at all just the imperfections within the 9ct.
Is there anyone else on here having problems detecting say gold nugets or 22ct gold ?

Sinclair you really need to clean up with a scope to get optium performance out of your build.

Regards
Dave