I read the article on the 17 meter add-on for Hustler 4BTV and was moved to experiment with it. However, having some aluminum tubing, I telescoped 13 feet of it into a vertical base and anchored it about 6-8 inches from my ground mounted 5 BTV. Then I proceeded to clamp a piece of #12 wire to the bottom of the base of the 5BTV to the base of the 17 meter tubing.

I tried it out today and was able to speak to Sun City, AZ and was given a report of 5/9. I still have to do some adjustments. SWR is negligible. SWR on all the other bands is OK. All the bands work well with the built in tuner as well as with the external tuner.

I am pleased with it and I am glad I read the article and saw the drawings for the 17 meter add-on. Thought you might want to hear about this modification that I did.

I have antenna restrictions and have to keep a low profile. I have a couple of guy nylon cords to hold the 5BTV and it is very well anchored on the bottom.

I have the 5BTV mounted on a stainless steel plate. I anchored the bottom of the antenna with short wires on the bottom and you will see the wires there which also serve as a ground. I put some decorating bricks around the stainless steel plate to avoid having someone getting tangled in them. I also guyed the 5BTV with two nylon cords so it would not sway too much, for in this area gusts of wind come often. You probably will see these in the pictures. At the side of the 5BTV you will see the 13 foot 17 meter add-on ground mounted beside the antenna and I do hope you can see the spacer. As you can also see, the antenna is in the midst of trees in the back yard.
See all of this in the pictures below and enjoy your 17 meter modification to the Hustler 5BTV vertical.

Closeup of the base the antenna with the 17 Meter modification.
Arrow points to "spacer" connection attached to the base of 5BTV.
The 17 meter vertical is fed from the base fo the 5BTV thru the "wire or metal spacer".
The "spacer" can be 6 to 10 inches long.
Some adjustment of the 17 meter vertical element may be needed
 for lowest swr depending on the length of your "spacer".