Homemade RF Chokes

Written by john papiewski | 13/05/2017
Homemade RF Chokes
Chokes are used in radio circuits. (Jupiterimages/Photos.com/Getty Images)

A radio frequency (RF) choke, also known as an inductor, blocks signals of a certain frequency. If you're building or repairing radio equipment, you can make your own chokes. You'll need a form on which to wind the inductor, wire and a calculator.


Wind the choke on a cylindrical form made of an insulator such as plastic or ceramic. You can use forms bought off-the-shelf or made from household odds and ends. The form's diameter helps determine the choke's inductance value. A hollow-centred form can accept an iron core, which increases the choke's inductance.


Magnet wire--copper wire with a thin insulating varnish coating--makes good material for making chokes. The thin insulation wastes little space when you need to make hundreds of wire turns on the form. Use a wire thin enough to save space but thick enough to carry sufficient current.


Before you wind a choke, you'll need to know its inductance value in microhenrys. Use the formula (D^2 x N^2) / [(18 x D) + (40 x Z)], where D and Z are diameter and length in inches, respectively, and N is the number of turns.

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.