Opened my tesoro widescan coil

[sinclairuser]

tv tube shielding paint works too, its a lot like guitar paint but its thicker and comes in two forms a dry powder you can mix with solvent or water, or ready mixed.

[kt315]

Nice coil.
One doubt, the strip that is not painted is really needed? Even if I use a DD coil? I'm asking that because I can't see that strip for example in a Minelab commander DD coil.
Thanks.

ML uses especial strip connected to preamplifier, on its input. or, you can show by pic your coil, your coil without the pre amp?

[kt315]

... for example

[cristiano.sar]

ML uses especial strip connected to preamplifier, on its input. or, you can show by pic your coil, your coil without the pre amp?

In this case I'm asking about the dfbowers coil casing having a strip (line) not painted with graphite. If having this not painted line is really needed (maybe because is coil is a concentric?), because I can't see something like that in Minelab commander coils (DD) shielding, like in the images below:

dfbowers casing (have a not painted strip / line):


minelab commander (full painted):


Thanks.

[Stevedbk]

My Minelab FT16000 has 2 flat impregnated paper disc shields. One above the double d and one under it. They are joined by a single flexible wire. The gap is in between the discs.
Maybe yours is the same.
Steve

[kt315]

understood. the gap perhaps needed if the layer has very low resistance, Ohms. without the gap the layer is like a short-circuited loop
for EMF (because TX power is EMF itself, the nature). you maybe want to reduce losses. has some sense. but if you do (right do) high resistance layer
you sure do not need doing the gap.
a case with discs, NO gap between discs. be cause high impedance graphite layer.
that was first way to protect in history - they use a paper with graph layer. later they use graph covering inside the housing,
Garret uses a special plastic with conductor for wire bobbins, like a mix. so you do not see a graph layer in Garrett coil but the ESFI protection is.

[cristiano.sar]

understood. the gap perhaps needed if the layer has very low resistance, Ohms. without the gap the layer is like a short-circuited loop
for EMF (because TX power is EMF itself, the nature). you maybe want to reduce losses. has some sense. but if you do (right do) high resistance layer
you sure do not need doing the gap.
a case with discs, NO gap between discs. be cause high impedance graphite layer.
that was first way to protect in history - they use a paper with graph layer. later they use graph covering inside the housing,
Garret uses a special plastic with conductor for wire bobbins, like a mix. so you do not see a graph layer in Garrett coil but the ESFI protection is.

Thanks for the perfect explanation.

[dbanner]

"In Dons document about shielding he masked off a line down the radius of the housing in order to stop eddy currents in the shield. I just did it anyway even though he found no difference with it and without it on his designs?he also said it was best practice." Quote from here:
http://www.adrianandgenese.com/blogg...housing-build/