Minipulse Rev D first attempt

[Qiaozhi]

ok i have tried this and it seems my laptop is the cause! the further the board gets from my laptop the less the erroneous signal presents it self i can only move so far but if get about half a meter away then the signal is nearly gone

so Qiaozhi i take it by "ringing" i am wrong again great! i tried at least!

so for the lack of depth i get my gold ring at about 4"
and a uk £1 at about the same or a little less

That's a lot lower than it should be.
What are the parameters of the coil?

[Impulse]

That's a lot lower than it should be.
What are the parameters of the coil?

the coil is a 3dss 8" (OSD) 0.5mm enameled copper wire.

[Impulse]

could it be the speaker? its a 32 ohm from maplins

http://www.maplin.co.uk/p/025w-mylar...ker-45mm-n95fu

[Impulse]

some pics of the board

[Qiaozhi]

the coil is a 3dss 8" (OSD) 0.5mm enameled copper wire.

What is the coil inductance?

[Impulse]

What is the coil inductance?

thats my next question how do i use my scope to measure the inductance?

[Qiaozhi]

thats my next question how do i use my scope to measure the inductance?

You need to use a meter that has an inductance measurement. It's invaluable for this type of work.

For example, with this one you can measure inductance, capacitance, resistance, and transistor hfe. -> http://www.amazon.co.uk/sourcingmap-Multimeter-Resistance-Capacitance-Inductance/dp/B0114KNPV0/ref=sr_1_3?ie=UTF8&qid=1459343416&sr=8-3&keywords=inductance+meter

[Teleno]

Finally I ordered a MiniPulse kit as a back-up just in case I can't finish my own PI project before the summer.

Do you think it'll work well with a DD coil? Tx is 540uH, 2.8 Ohm; Rx is 13mH, 36 Ohm.

[Impulse]

You need to use a meter that has an inductance measurement. It's invaluable for this type of work.

For example, with this one you can measure inductance, capacitance, resistance, and transistor hfe. -> http://www.amazon.co.uk/sourcingmap-Multimeter-Resistance-Capacitance-Inductance/dp/B0114KNPV0/ref=sr_1_3?ie=UTF8&qid=1459343416&sr=8-3&keywords=inductance+meter

I have ordered one should be here tomorrow

[Qiaozhi]

Finally I ordered a MiniPulse kit as a back-up just in case I can't finish my own PI project before the summer.

Do you think it'll work well with a DD coil? Tx is 540uH, 2.8 Ohm; Rx is 13mH, 36 Ohm.

The MPP is designed to work with either a mono or balanced coil. It might be ok with the coil you've specified, but the only real way to find out is to try it.

[baum7154]

[QUOTE=Impulse;215530]Hey guys i have gone through each step and all have been a success but i have no depth with my test coil which is a 3dss 8" 0.5mm enamelled copper wire coil
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How many turns of wire is your 8" 3DSS coil? I believe my 8" is 32 turns and measures 334uh. This should give you a benchmark, however mine is wound with 24awg stranded 600 volt PTFE insulated wire which lowers interwire capacitance and raises self resonant frequency.

Perhaps you could post a picture of it.

Good luck,

Dan

[Impulse]

[QUOTE=baum7154;215661]

Hey guys i have gone through each step and all have been a success but i have no depth with my test coil which is a 3dss 8" 0.5mm enamelled copper wire coil
________________________________________________

How many turns of wire is your 8" 3DSS coil? I believe my 8" is 32 turns and measures 334uh. This should give you a benchmark, however mine is wound with 24awg stranded 600 volt PTFE insulated wire which lowers interwire capacitance and raises self resonant frequency.

Perhaps you could post a picture of it.

Good luck,

Dan

Here's a picture of the coil

[baum7154]

From the number of wires in the slots it looks like you have between 27 turns to 29 turns which should put the coil in the vicinity of 300uh. What is the width of one side of the coil form, is it greater than 1"? Do you know the distance between the innermost ends of the outer and the inner slots and also your slot depth? These dimensions do have an impact on the coil value and the performance.

Regards,

Dan

[Impulse]

Hey guys i have the inductance meter heres a picture, now how do i use this properly? eg coil on or off board? setting 2H?



thanks in advance for any help

[Qiaozhi]

Hey guys i have the inductance meter heres a picture, now how do i use this properly? eg coil on or off board? setting 2H?

[ATTACH]35761[/ATTACH]

thanks in advance for any help

Try it on the lowest inductance setting. i.e. 20mH
And with the coil disconnected from the circuit.