so... I'm doing this Wireless microphone schematic
and i have a couple of questions... it says that L1 is 3mm in diameter with 5 turns 0.61 mm copper wire. what does this 0.61mm mean? the lenght of the wire?
another thing. the antenna.. so if i for example use 90MHz frequency i need to get 45cm of wire for the antenna according to this? and what kind of wire should i use for the antenna? thanks guys

 

The wire diameter is 0.61mm and you wind a coil of it on a former which is 3mm in diameter. The coil has 5 turns of wire wrapped around the former.....

You dont say where you are location wise, the wire is 0.61mm in diameter, that from tables is 23 SWG in English money..look here Wire Gauge Reference Table
about 2/3ds down the page....

For the antenna wire just use some thin pvc hook up wire

__________________
Eccentric millionaire financed by 'er indoors

 

That would be AWG14. The coils don't care a lot how heavy the wire is (within reason) as long as the dimensions are met. They are wound with stiff wire so they don't move.

The output isn't near any standard antenna impedance. 45cm is fine. There are many ways to make a better antenna with radial wires at its base (look up ground plane).

Any single conductor wire will function electrically. Some people use stiff wire because it stays straight more easily.

__________________
de KI6RWX