Baracuda Voltage Readings

[Paul B]

Hi
My name is Paul and this is my first post
I recently bought the Baracuda Legend, Alex / Ap Rev2 kit, from Silverdog

Unfortunately at the moment it has very poor detection
A pair of pliers at about 4 inches
A Twenty cent piece at about 2 inches
Does not detect a Ten cent piece
Does not detect Gold

Below are the voltage readings
If some could post the voltage of a working Baracuda,
It would help me find what’s wrong with my Baracuda
Your help will be greatly appreciated

TC 7660 S

Pin 1	7.75	Pin 5	-12.4
Pin 2	6.4	Pin 6	7.7
Pin 3	0	Pin 7	7.3
Pin 4	-6.2	Pin 8	12.7

LF 412 CN

Pin 1	4.4	Pin 5	0
Pin 2	-0.03	Pin 6	0
Pin 3	-0.3	Pin 7	1.8
Pin 4	-4.9	Pin 8	5

NE 5534 AP

Pin 1	2.9	Pin 5	-0.23
Pin 2	0	Pin 6	0
Pin 3	-0.3	Pin 7	5
Pin 4	-0.6	Pin 8	2.76

HEF 40106 BP

Pin 1	0.6	Pin 8	-4.7
Pin 2	-4.8	Pin 9	-0.23
Pin 3	0.6	Pin 10	-0.23
Pin 4	-4.8	Pin 11	-3.26
Pin 5	0.18	Pin 12	-4.86
Pin 6	-4.46	Pin 13	-0.05
Pin 7	-4.9	Pin 14	0

79L05
Out -4.93

78L05
Out 5.00

[Locouarn]

Hi,
My name is Michel (I'm french) and it's my first post too. I've just assembled my Baracuda yesterday evening and I am just on testings.
I dont know how you have mesured these voltages, but I expect that it's with a simple multimeter.
Then, you can verify supply voltages (7805 and 7905 ie are good) and VCC / VDD of the CIs.
The most of other voltages are not continuous (and some various frequencies) and I dont think you can read with a multimeter, but with a scope.
Regards.

[kt315]

a time to redesign of Bara board?

[Koala]

Does IRF9640 or TIP127 get hot quickly


If you reduce the volts to just bellow 8 volts does the distance increases.

[jladre]

Does IRF9640 or TIP127 get hot quickly


If you reduce the volts to just bellow 8 volts does the distance increases.

It does not get hot quickly. My bara works without heatsink. It just get warmer but not hot. Incorrect damping resistor value is one of the cause of getting it hot. Lowering the voltage will just make the bara unstable.

[Paul B]

Michel

I don’t have an oscilloscope, just a multimeter.
Thanks for the info, hope yours goes well,

Koala

IRF9640 slightly gets warm
Does not run below 8 volts, just goes beep, beep, beep


I carefully cleaned the back of pcb with Isopropyl Alcohol
Now it detects a Ten cents at 2 inches
Twenty cents at 6 inches
Dollar coin at 7 inches
Haven’t tested on gold yet, but at least I’m heading in the right direction
Now its time to experiment with coils

[jladre]

For best coil i suggest a spiral coil ir a spider web coil.

[Koala]

"IRF9640 slightly gets warm
Does not run below 8 volts, just goes beep, beep, beep"

Sound like the 2n2222 is correct. There are a lot of versions some with completely different pin outs. Normally the cause of bad detection depth.

Sound like it will just be a matter of dialling everything in.

Gold ring seems to best for setting up delay and offset. Did you set offset to 0 volts. This is not always the best. Trial and error for best distance.

[Koala]

It does not get hot quickly. My bara works without heatsink. It just get warmer but not hot. Incorrect damping resistor value is one of the cause of getting it hot. Lowering the voltage will just make the bara unstable.

Just seeing if the 2n2222 is the correct way found. 180 digress out and the FET will instantly get hot unless the volts are below 8 volts.

[Paul B]

The 2n2222 is the correct way round,
Already tested, when I put it in 180 degrees, the IRF9640 got hot very quickly
Put it back in the right way round and the IRF9640 only gets warm

I made a spider web coil and now it detects a gold ring at about 5 inches
Going to experiment with other coils over the next few days and will update then

Thanks for all your help