BARACUDA-Legend-1

[dfbowers]

Hi Don,
I guess I should have explained my post better. On my Barracuda I have externally mounted a Time delay Pot. in series with the onboard Time Delay pot (fine and coarse). I also made both the threshold and Sensitivity pots external/remote. Having the Sensitivity pot external allows you to optimize the detector based on the ground you are hunting (this adjustment had a noticeable effect between air testing and real life hunting situations when I was adjusting/setting mine up). The sensitivity acts similar to a Ground balance on my detectors.

The "Tone ID" I was referring to was brought to my attention by a friend of mine. Based on where you have the Pulse Delay set, large targets/ Large emf fields (quarters, cans, large iron, big brass items) respond as you approach the target, go silent when directly over the target, then sound off again as you leave the target (similar sound as going over a "cold rock" with a vlf in All Metal). Smaller items (pulltabs, nickles, rings, small brass, nuts, foil) give a quick solid sound all the way through the coil swing.

Quote from the review "In the field, iron objects produce a wide, washed-out signal when compared to the sharp, crisp signal from a non-ferrous object, such as a coin or ring".

I have never used the Whites Surfmaster and not sure if it responds similar to this. the only other PI's I have used is an Infinium and GPX 5000. Hope this cleared things up a bit.

Adam

Thanks Adam. Did you find that the offset had any type of interaction with the delay pot or do you just set yours for 0V on the NE5534? Did you add a sensitivity adjustment as well?

[Vortxrex]

This happen!!! with the TIP 127 not with a replacement FET ...

I think we should all play "Connect the dots" between the interaction of "certain" components and the audio tone "discrimination" of the original BARACUDA

Dave Frank

[Vortxrex]

Hi dfbowers. The silverdog kit no potentiometer DELAY = 10K ( external - fine adjust), instead it is a "bridge".

You can just add "trim" potentiometer in series (on one lead) w/ a remote mounted DELAY potentiometer.


Dave Frank

[adam(Va)]

Don,
On my PCB I removed the 25K Offset pot for NE5534 and replaced it with a remotely/ externally mounted 12k pot. I tried just setting the internal offset pot for zero volts on the bench but found that in real world use this had to be set in the field because at zero(max sensitivity) it will pick up the Ground it self as a target (very noticeable when ever the coil is bobbed up and down and at the end of swings). Yes you are correct that there is some slight interaction between the offset and the delay pot. This has some effect on where the "washed out sound" occurs based on where both the external pulse delay pot and where the offset pot is set. I believe this another reason the manufacturer (JP) had to manually adjust each one of these in the field. By not having an external offset adjust you would have to tweek it in the field to find that happy medium between dry land vs beach sand vs saltwater, but please don't take this as the Gospel truth, that is just some of my findings on my detectors.

adam

Thanks Adam. Did you find that the offset had any type of interaction with the delay pot or do you just set yours for 0V on the NE5534? Did you add a sensitivity adjustment as well?

[TH Jim]

Hi Folks,

I think possibly another variable that affects the setup of the Baracuda is the switch on voltage of the gates and how well they are matched as this affects the speed and intensity of the signal buildup on the LM358 section. This will be different on all our machines making comparison a bit more tricky.

Also I found whilst setting mine up that it seemed to work well over a wide range of offset values on the NE5534 when bench tested with coin size targets, but in the field I found that the LM358 was being saturated for large targets and thus the audio tone would persist long after the coil had passed over the target.

Hope this is of use, I had similar issues with the surf pi, there must be a methodical way to do this correctly????

Regards, Jim.

[adam(Va)]

More findings on my Cuda' through trial and error

I changed U4 from a TL072/ LF412 to a TL082 and my Threshold Volume was noticeably louder.
I smoked/weakened my original IRF9530( 12amp 100v) messing with the dampening resistor (It had a constant wavering noise that would not go away) and replaced it with a TIP42G (40v 6amp PNP transistor) and it actually worked fairly well but have since replaced it with an IRF9640 (11amp 200v P channel Mosfet) just to avoid smoking it again. Also replaced the Threshold, Offset/ sensitivity, and remote Pulse delay pots all to 12k (mostly because of availability/ convenience although changing the offset pot to 12k helped a lot, the 25k pot was overkill with the range/ resolution).

Adam

[6666]

Grant
received your Bara pcb's today
will start looking at them today

6666

The good news is one is working with my coil

I changed U4 from a TL072/ LF412 to a TL082 and my Threshold Volume was noticeably louder.

thats worth a try thanks

[6666]

Grant
the 2nd pcb seems to have a power problem
but early days yet

[adam(Va)]

Would it be beneficial to add this Surf Pi Audio mod to the Cuda?

I guess I would need to remove D7, D10, D11, and R36 (battery charge protection circuit) I don't have the LED installed either. Would it help increase/ smooth out the audio?






Maybe this would be better

[Wilson]

Hello, I'm also going to ride the Barracuda, the function switch SW1 seems to be a pimpointer when pressed continuously, the FET Q5 puts the R25 200K resistor in parallel with the capacitor C14 470kpf thus reducing the set RC formed by R26 and C14 achieving a level dc more continuous, resulting in a constant and continuous sound, making it easier to locate the target. I'm sorry if I'm wrong.

[gcause]

Grant
received your Bara pcb's today
will start looking at them today

6666

The good news is one is working with my coil





thats worth a try thanks

Excellent news, really appreciate your efforts, not expecting miracles just keen to learn what I did wrong so I dont repeat my mistakes. PM sent.

[golfnut]

ADAM

If you are smoking lesser FETs you may improve them with a schottkey diode..

as attached..

most of the hi voltage fets have these in the package and makes them a hi volt device

[plumabob]

Fo Finderskeepers

What kind of depth are you getting with that Commander coil if you please. Say on a man's size gold ring?

Bob

[Finderskeepers]

The detection depths (air test) with an 11 inch commander coil;

mens gold wedding ring - 30cm
50 u.s. cents - 20cm
5 aus. dollar gold coin (1/20 ounce) - 18cm
1 dollar coin - 27cm
50 aus. cents - 34cm
20 aus. cents - 31 cm
5 aus. cents - 22cm
1 euro coin - 30cm
50 euro cents - 26cm

I have experimented with resisitor R1 and found that a 680 ohm resistor worked quite well.

[plumabob]

Thanks for getting back. I wanted a comparison with my homemade 12 inch mono and I'm right there with yours on the air testing. I will try swapping out the R1 when I get a chance to see if there is any improvement.

Regards,

Bob