End of the Mineoro link on youtube

[WM6]

Originally Posted by ivconic

. For example; i would like to know how they calculated coupling relation between Al loop and small coil inside it? What relation? What is resonance of Al loop? What happening if loop was with different sizes? What are merrits and what drawbacks from such coupling. Is loop size dependable on working frequency and how? How possibly that loop can be suitable for such low frequency? Is it the coupled coil the one which solving that issue?

What do you mean by "Al loop and small coil inside it"? Maybe schematic is some unclear regarding coils, but Al loop are not inductive coupled to "small coil" but electric connected by wire in one only coil. "Small coil" are secondary winding inside ferite potcore and form togheter with Al loop one coil which resonate down harmonic to primary (tunable) LC tank. So loop and "small coil" byself resonate out of TR frequency and are by this only slightly coupled which cause by near target escape from balanced (tuned) nulling at given resonance and by this tone in RX (like by un-nulled device).

[ivconic]

Originally Posted by WM6

What do you mean by "Al loop and small coil inside it"? Maybe schematic is some unclear regarding coils, but Al loop are not inductive coupled to "small coil" but electric connected by wire in one only coil. "Small coil" are secondary winding inside ferite potcore and form togheter with Al loop one coil which resonate down harmonic to primary (tunable) LC tank. So loop and "small coil" byself resonate out of TR frequency and are by this only slightly coupled which cause by near target escape from balanced (tuned) nulling at given resonance and by this tone in RX (like by un-nulled device).

Is that was the case!? I mixed it up than! Had also another project on my mind. Never mind, my question is still there, only preformulated. Calculations..i am interesting to see what calculations were used there..

[ivconic]

Since my memory is not serving me well lately i just checked at :

http://www.geotech1.com/forums/showt...ighlight=tm808

and yes, that's what i ment, although i formulated it wrong.
Al loop is connected with primary winding and IT IS COUPLED with secondary winding.
You are right and i am right also. Only i missed to say that loop is a part of primary coil...
So...i will preformulate again question; what are calculations for relation between loop dimensions and primary coil? And all that in relation to secondary coil? How to calculate best relation?
For example; i would want to make loop with much different dimensions, so i must correct primary and secondary coils also, right?

[WM6]

[quote=ivconic;106244]Since my memory is not serving me well lately i just checked at :

http://www.geotech1.com/forums/showt...ighlight=tm808


Sorry, I am not discuss TM808, I discuss "Deep seeking metal locator" by Phil Wait and Roger Harrison you mentioned in post #25. I do not remember TM 808 schematic, I was never interested in it.

[ivconic]

Sorry, I am not discuss TM808, I discuss "Deep seeking metal locator" by Phil Wait and Roger Harrison you mentioned in post #25. I do not remember TM 808 schematic, I was never interested in it.

Never mind actually. Principles should be the same.