I am getting ready to place a choke at the feedpoint of my half sloper,
hoping to lower the noise level.

Question: would the same action help with a normal beam (a 3-element
SteppIR, in this case)? I think there is a balun of some type in the driven
element of the SteppIR, and I do not know how much this rejects noise pickup
on the external shield of the coax. (The coaxes for both antennas run about
50' underground, and then about 60' up the tower.)

Bill - W2WO