What size antenna?

Is there a typical diameter wire used for 1/24 scale antennas?

Just divide whatever the real diameter is by your scale which in this case is 24. Example… if the real thing is .125" then the scaled down version would be .005"

What if you don’t have the full scale original to go by?

next time you’re out of the house pull into a parkiing lot and check avaible samples, with a string and measure the distance when you get bacto your bench