hi everyone
could do with a little help here
i have a schematic of a transmitter but the problem i have is this
the area marked in red says 5 turns of 0.5mm 3.5mm dia
so is it 5 turns of 0.5mm over 3.5mm in wound length
or is it 5 turns of 0.5mm to 3.5mm enameled wire
or is it 0.5mm wire 5 turns over a 3.5mm non inductive core
thanks
for any help

marko

 

First, let us declare that the wire diameter is .5mm. It does not need an enamel coating at 3 volts unless it is going to be very bunched up, so I will ignore coating thickness. The original formula refers to "mean diameter" and that would mean a form that is 3.25mm OD on which you wind 5 turns. Most people use a bolt to get the windings evenly spaced. After the project is built and the frequency is wrong, they bend the coils to use up more length, thus lowering the inductance.

ps, it is probably "air core". Air has a permeability and that is probably what is wanted.

 

hey whozsoevr dis post iz..can u plz tell is this ckt u provided here worked or not ???...can u give a little description of it !