Hi,
Is there a method for obtaining the number of turns for a given
diameter for the antenna choke ? (I am not sure if this will be simple
air-core coil formula or "suck it and see" type arrangement).
ie. I have a sleeve antenna at 915MHz constructed from RG316 coaxial
cable. It is fed up the centre of 1/4" nylon tubing. I want to create a
choke at the feedpoint from the RG316 wound around the outside of the
1/4" tubing but not sure of how many turns would be required.

Thanks in advance

Regards

David