Barracuda Legend Kit Problems

[kt315]

use my schematic but it maybe not fitted your (silverdog) board.

[Impulse]

Ok i have taken readings from the 40106 and pin 1,0.55v 2,4.9v 3,0.48v 4,-4.8v 5,0.16v 6,-4.7v 7, -4.9v and pin 14, 0v. i have borrowed an o-scope but it will not turn on atm batt is flat across the coil and 8.3v AC 0.22v DC and now the board does not function at all nothing not a beep unless i pull the power off it and i get a whine as the power drains, nothing changed ?

[kt315]

it seems -E is OK. a digital meter gives wrong value if a voltage is not symmetrical and not sinusoidal, on AC range or DC, no difference.
you have not to take attention on those voltages.

[Impulse]

hey guys i have built another board and have managed to get the coil to pick up a gold chain next to the coil i have set pin 6 to 0V again and i have tried to get the tone to change but nothing happens, i have noticed a strange thing the coil hums not the speaker (dont worry i havent connected them the wrong way around) unless i wave a piece of metal infront of it (the coil) and the mosfet gets warmer than i would like

[kt315]

the coil hums --->>> hey guys my coil is 10" Dia 20 turns magnet wire 0.5mm 1.7 ohms

[Impulse]

yes but no matter what position the threshold i do not get any change in tone?

[kt315]

in my Bara reaction on metal is in any position of the threshold pot. i also did not tune opamp nulling offset balance pot
and delay preset pot setting them in a middle position. all working without the specs.

[Old cart]

If it is a fine gold chain then weak response is to be expected. Do you have a mans gold ring or a US nickle to try? you should get around 10" or more if everything is as it should be. For fine gold setting the minimum delay is very important. I described how to do that in post 22.

[Impulse]

Hey old cart i have a large ish gold chain and it was picking it up (very close) but now i cannot get it to work i really want this to work , i have the o-scope working now but it is a fluke 196c and i have no idea how to get it to where it should be, can you help? when i adjust the bottom (blue w203) delay pot it does not seem to make any odds where it is it doesnt make the tone louder.

[Impulse]

Hey everyone thank you for your patience and help i have had another play with the new board and i have managed to get it to pick up a gold ring about 5-6 (good or bad?) away i have ordered some new 0.5mm enamelled wire so i can make a more precise coil. What have you found to be a better design/size for the coil searching for coinage, rings and relics ect? I know this is a question that has loads of answers but im looking for the best place to start as you guys have been using the barracuda in 'real world' situations, would the basic mono coil be best for roughish to smooth beach or some other variation? also whats with the shielding as i have tried with foil but it only made things worse not better which thought i should do?

[kt315]

do basket coil http://www.metdet.ru/Sensor_K1.htm
you may use Google translation.

[Impulse]

Nice page! thank you, is 1ohm a bit low or not? what about the balance resistor would i have to change this? i notice the inductance is 317 for such a low ohms? (sorry lack of knowledge again) so i take there is no linear relationship between inductance and resistance of a coil? Any one have a shread of knowledge?

[Koala]

Hey everyone thank you for your patience and help i have had another play with the new board and i have managed to get it to pick up a gold ring about 5-6 (good or bad?) away i have ordered some new 0.5mm enamelled wire so i can make a more precise coil. What have you found to be a better design/size for the coil searching for coinage, rings and relics ect? I know this is a question that has loads of answers but im looking for the best place to start as you guys have been using the barracuda in 'real world' situations, would the basic mono coil be best for roughish to smooth beach or some other variation? also whats with the shielding as i have tried with foil but it only made things worse not better which thought i should do?

Takes a bit of playing around. I adjusted the offset for best results not 0 volts.(best sensitivity to small gold ring)

Different coils affects all the adjustments. Best to tune your detector when your new coil is built.

[6666]

Takes a bit of playing around. I adjusted the offset for best results not 0 volts.(best sensitivity to small gold ring)

Different coils affects all the adjustments. Best to tune your detector when your new coil is built.

Koala just for interest what was the offset voltage that gave best results ?

[kt315]

Nice page! thank you, is 1ohm a bit low or not?

you must get MICROHENRY,- L, NOT THE OHMS. low or hight - has not have difference for you now.