The Hustler 4BTV, 5BTV, and 6BTV trap vertical antennas have been sold for as long as I’ve been a ham (37 years now!). I’m sure they’ve sold thousands of them. They are inexpensive, rugged, and when used with a good number of radials, great antennas.
The one problem is that they were designed before we got the WARC bands, and Newtronics has not updated the design to add these bands. Well, here’s an ingenious way to add 17m to the Hustler antennas.
Basically, all you do is add a quarter-wave of wire (about 13 feet) in parallel with the rest of the antenna. You connect one end to the base of the antenna, and then suspend the top from the capacitance hat, as shown in the figure at the right. Apparently, if you space it out at least six inches from the main element, the antenna will tune up just fine on 17m and not affect the tuning on the other bands very much.
You should be able to add a 12m element to the antenna in exactly the same way.