a hypothetical question. please stop me before it's too late!

[ejudasf]

Hello everybody.

First I would like to thank everyone who has posted ideas, plans, schematics, and above all, the help everyone offers.

I am impressed with the Bandido projects that have been completed, and even the ones that may not be complete yet. You guys that are making your own coils, you all rock!

Now to my hypothetical question. Again, please stop me if you think it will burn something.

I have a Bandido II uMax. I have 3 different coils for it. I would like to re-wire a coil connector on one of the HOT coils, like for the Tejon, to see what effects it would have on the Bandido.

I think, worst case scenario, is that the machine would be totally unstable and un-usable. But it could work okay. What's a few KHz among friends?

Some coils are made for the 10-12KHz machines, and the HOT coils are made for the 14-17KHz machines. So I figure it could work.

One other question I have. Can a multi-meter with a capacitance option be used in a way to measure mH?

Thanks for any suggestions or comments.

ed

[chemelec]

Hello everybody.

First I would like to thank everyone who has posted ideas, plans, schematics, and above all, the help everyone offers.

I am impressed with the Bandido projects that have been completed, and even the ones that may not be complete yet. You guys that are making your own coils, you all rock!

Now to my hypothetical question. Again, please stop me if you think it will burn something.

I have a Bandido II uMax. I have 3 different coils for it. I would like to re-wire a coil connector on one of the HOT coils, like for the Tejon, to see what effects it would have on the Bandido.

I think, worst case scenario, is that the machine would be totally unstable and un-usable. But it could work okay. What's a few KHz among friends?

Some coils are made for the 10-12KHz machines, and the HOT coils are made for the 14-17KHz machines. So I figure it could work.

One other question I have. Can a multi-meter with a capacitance option be used in a way to measure mH?

Thanks for any suggestions or comments.

ed

If you Asking if it will Damage the Bandido, the Answer is NO.

For Inductance, You need a Inductance meter, Or you can do it with a Signal generator, capacitor and a Scope.

Possibly a Signal generator, cap and a Multimeter, but not as good.

But you DO NEED the Frequency Generator with a Known, Variable Frequency Output.

[Max]

Hello everybody.

First I would like to thank everyone who has posted ideas, plans, schematics, and above all, the help everyone offers.

I am impressed with the Bandido projects that have been completed, and even the ones that may not be complete yet. You guys that are making your own coils, you all rock!

Now to my hypothetical question. Again, please stop me if you think it will burn something.

I have a Bandido II uMax. I have 3 different coils for it. I would like to re-wire a coil connector on one of the HOT coils, like for the Tejon, to see what effects it would have on the Bandido.

I think, worst case scenario, is that the machine would be totally unstable and un-usable. But it could work okay. What's a few KHz among friends?

Some coils are made for the 10-12KHz machines, and the HOT coils are made for the 14-17KHz machines. So I figure it could work.

One other question I have. Can a multi-meter with a capacitance option be used in a way to measure mH?

Thanks for any suggestions or comments.

ed

Hi,
could work. Don't worry about burning...cause it's really hard to do with bandido inputs any damage to the circuit. Just take care e.g. at tx transistor collector wire...just as precaution to avoid too load on it if you connect to gnd...or to a lower resistance than 22ohm (like in original coils). But also in this case you get something not dangerous...just a bit more current in tx transistor (10mA or something...not a real problem)!
Bandido is, from this point of view, a rock !
Some dubts on frequencies...like shield(s)...inductances...but I think that lowering operating frequency couldn't be a problem and coil may works fine.
Let us know if hot coils work too on uMax !

Best regards,
Max

[Geo]

Hi
Make it . There is not problem .
Before on year i made the bandido oscillator and connected to it a coil with very small inductance (500uH if i remember ok ). The oscillator had not any problem so don't afraid. Try it.

[ejudasf]

I took ohm measurements, and this is what I see. . . .

Hi again.

On the uMax coils, according to other posts, the TX and the RX windings between different coils, differentiate alot between them.

7-inch concentric TX 21 ohms
RX 31 ohms

8-inch concentric TX 23.1 ohms
RX 23.8 ohms

4-inch concentric TX 28.6 ohms
RX 29.1 ohms

On the HOT coil I have, I don't know which is TX or RX, but each is a shielded conductor. Pins 1 and 3 are either TX or RX, and the Pins 2 and 4 is the other. The ohms reading for these are:

Pins 1 & 3 - 5.1 ohms
Pins 2 & 4 - 65 ohms.

Big difference.

I have decided not to go thru the trouble becasue the 5 ohm reading is might cause a loading problem.

What do you all think?

[Geo]

5.1 Ohm is the Tx Winding.
Bandido oscillator has a resistor 1k2 in series with emitter and limit the current <10 ma. So it is imposible to destroy the transistor.
Try it

[ejudasf]

Failure on coil swap.

Complete and utter failure.

As soon as powered on, the machine's 'battery check' tone was higher than normal.

In all metal mode, the reaction was opposite than expected. The machine would null when the target, (dime and quarter), would come to the center of the coil. The target had to pass a little faster than normal.

In Disc mode, the machine would not detect any target, unless it was about an inch to the coil and moving fast.

The only good thing, is that now I know what happens, and I am not curious anymore.

Thanks everybody.

ed