DD and Concentric

[plboy]

thx Qiaoshi
I am made some DD coils and put the gap in a convenient place - no problem...but I want to make a good coil..... which type of coil will be recommendation

[Qiaozhi]

yes thx Qiaozi
I make this one but it is important to make a 'gap' between TX and RX coils in the middle or can make it everywhere on the coils.

Without a gap, eddy currents will flow freely around the loop, and act like a shorted turn. The position of the gap is not important. Just make it in a convenient place.

[plboy]

yes thx Qiaozi
I make this one but it is important to make a 'gap' between TX and RX coils in the middle or can make it everywhere on the coils.

[Qiaozhi]

Where i have to made the gap of shield for the DD Coil, is it nessesery to leave this 'gap' between Tx and Rx in the middle

You need to have a "gap" in the shield on both the TX and RX coils, but you must insulate the shields from each other where the coils cross. Otherwise this will effectively create a single-turn loop.

[plboy]

thx Geo

About 0.5... 1cm is OK if you use foil for shielding
If you use graphite spray then a thin line 2mm on the coil housing is OK

Where i have to made the gap of shield for the DD Coil, is it nessesery to leave this 'gap' between Tx and Rx in the middle

[Qiaozhi]

您是愚笨的 fred.
qiaozhi 是說謊者.
he is not chinesse.

[Qiaozhi]

Hi exactly thought about him when i saw this
However i could not think one coud be stupid enought to use a translator with someone that obviously understand Chinese.
"you are not our people", Ugh!

Regards,
Fred.

[Fred]

Hi exactly thought about him when i saw this
However i could not think one coud be stupid enought to use a translator with someone that obviously understand Chinese.
"you are not our people", Ugh!

Regards,
Fred.

[Qiaozhi]

您不知道传统语言

ok. you do not know traditional!? i was right, you are not chinesse.

And you do not understand Chinese at all!
Nice try Hung ... but no cigar!

您不知道传统语言

ok. you do not know traditional!? i was right, you are not chinesse.

[Qiaozhi]

為什麼是您說謊這裡您是您不是我們的人的英國人
是您羞辱是你自己
我不證明這

聰明告訴您是的人民

Anyone can use an online translator to generate Chinese.
I wrote in pinyin, but you replied with traditional Chinese characters.

I'm not using a translator.

Concentric coils are better one. Due to concentric design, the temperature and therefore balance distortion effects are low.

為什麼是您說謊這裡您是您不是我們的人的英國人
是您羞辱是你自己
我不證明這

聰明告訴您是的人民

您不是我們的人
問候