BARACUDA-Legend-1

[bernte_one]

thx silverdog
got my baracuda working
3 hours of work from fr 9:30pm till sa 0:30
first test above 30cm for 1 € coin with 23cm coil 490microH and 1R

http://fotos.web.de/bernd.marten2/Baracuda

[ApBerg]

thx silverdog
got my baracuda working
3 hours of work from fr 9:30pm till sa 0:30
first test above 30cm for 1 € coin with 23cm coil 490microH and 1R

http://fotos.web.de/bernd.marten2/Baracuda

Hello Bernd,

Nice work !
I see you use a 5V dc magnetic buzzer ?? If you remove the fet (MPF102)that is standing near the MPSA 13 the sound is better !?
That MPF 102 fet make's the audio sound, it connects the dc out from the opamp,in a audio freq, to ground ...so the speaker can make sound.
Keep in mind that a normal 8 ohm speaker without the MPF102 will not work !
If you use a dc pager motor ( vibrator motor from mobil phone) the fet also has to go...

Best regards

Ap

[bernte_one]

Hello ApBerg,

thanks for the info, i will keep it in mind.

The buzzer is always used for first testing, at finished detector i normally use a sennheiser cx300 or cx500(with vol control) they give the best sound and fits into pocket of my pants.

some infos that i need.
what makes the sw1? a user says it is used for fine tuning another for battery check
and there is a bridge besides the delay pot but i see that it is replaced sometimes by a pot - also finetuning or is the bridge better?

I had ad to take a closer look. It was too late when i finished.

[ApBerg]

Hello ApBerg,

thanks for the info, i will keep it in mind.

The buzzer is always used for first testing, at finished detector i normally use a sennheiser cx300 or cx500(with vol control) they give the best sound and fits into pocket of my pants.

some infos that i need.
what makes the sw1? a user says it is used for fine tuning another for battery check
and there is a bridge besides the delay pot but i see that it is replaced sometimes by a pot - also finetuning or is the bridge better?

I had ad to take a closer look. It was too late when i finished.

The SW1 switch give's the detector a non motion mode( pinpoint ?).... I think. If you close the switch the fet connects the resistor R25 parallel to the cap C15.
If cap C15 is on his one only a chance in detection gives results, so if you do not keep moveing a target under the coil there wil be no result any more...If resistor R25 is added parralel to cap C15 also a not moving object under the coil gives result..

If somebody can give a better expanation...or if it works on a other way ?

[ApBerg]

Hello ApBerg,

thanks for the info, i will keep it in mind.

The buzzer is always used for first testing, at finished detector i normally use a sennheiser cx300 or cx500(with vol control) they give the best sound and fits into pocket of my pants.

some infos that i need.
what makes the sw1? a user says it is used for fine tuning another for battery check
and there is a bridge besides the delay pot but i see that it is replaced sometimes by a pot - also finetuning or is the bridge better?

I had ad to take a closer look. It was too late when i finished.

If you remove the wire link ( bridge ) beside the delay print pot you can use the connections from that wire link for a potentiometer outside... the print pot lets you them pre-adjust the delay and the outside pot is for use in the field..

Best regards.

Ap

[bernte_one]

nice ApBerg

thought it already, when switching the sw1 it gives a constant tone like pinpoint mode.
I think it should replaced then by pushbutton.

For the wire link besides delay -what´s the common resistor value?

Only asking this time because i´m planning the front plate, thx.

[TH Jim]

Hi Guys,

Having a quick look at the hand drawn circuit posted earlier in the thread by Alex? Does anyone else think it is strange that the gates are different? Surely they would both be the same component right?

2N5458 or MPF102 ????????????

Regards, Jim

[oros27]

pcb

[WM6]

pcb

Great! Thank you oros27. What about silk screen view?

[Alexismex]

Hello TH jim,
I think the same like you , 2 reasons:
1- it is better with this two different fets
2- they finish the stock of Mpf 102 o vice versa and they solder what they have in their hand !!!

[ApBerg]

The SW1 switch give's the detector a non motion mode( pinpoint ?).... I think. If you close the switch the fet connects the resistor R25 parallel to the cap C15.
If cap C15 is on his one only a chance in detection gives results, so if you do not keep moveing a target under the coil there wil be no result any more...If resistor R25 is added parralel to cap C15 also a not moving object under the coil gives result..

If somebody can give a better expanation...or if it works on a other way ?

Hello Friends,

Today did some test... think now that the switch is not for a non motion option ...if you look at post no. 56 from Smity, I think he is very close.
In combination, offset potentiometer and time delay potmeter, you can find with the switch closed a break point in audio on/off . The point where there is just silence gives always the best sensetivety for that , delay/offset, adjustment.
With this , just silence, adjustment is the output from opamp U4 pin 1 always around zero...

So where can we use this for ??

Best regards.

Ap

[ApBerg]

Hello TH jim,
I think the same like you , 2 reasons:
1- it is better with this two different fets
2- they finish the stock of Mpf 102 o vice versa and they solder what they have in their hand !!!

Hello Alexis,

Have made some different tests with some fets.... think your option no.1 is the one....

1- it is better with this two different fets

Aslo other fet ( conminations ) work but not as good ....

Best regards.

Ap

[ApBerg]

ATTENTION

Hello Friends

Now there are more BARACUDA boards on the way....some ATTENTION

As you can read in post 65 you need to look carrefull at the 2N2222 connections, the text on the pcb is good, but the symbols outline can give a wrong indication....

There are 2 versions for the 2N2222 a metal and plastic version,

Check your 2N2222 versions E/B/C connections so that it is correct with the E/B/C on the board!

Succes

Ap

[Janou]

Hello, i'm new on the board

I'm totaly a beginner for treasure hunting, but after would build a hammerhead D, i finaly choice the baracuda and order a kit to silverdog.

I really like the simple schematic of Baracuda, si i'm here now

One query to ApBerg, i love your coil, do you compare with more "standard" wire, is it a choice for experimentation or something like that ? Do you think it's a good choice ?

Other more global query about calibration of the detector, have you a calibration sheet or something to do correctly the job ( i have a scope etc ) sorry if the query is not interesting

[ApBerg]

Hello Janou,

Look at the surfmaster and baracude info for coils, it is easy to make a coil for a PI detector, if you realy want to make a good fast coil look at the info from BBsailor.

For baracuda adjustmenst... look at the scope photo's, but there can alway's be better way's ?