Sorry for such a delayed response, just spotted your query. If it's not too late to be helpful: The R-S TV antennas are not worth modifying for 70cm. Just about everything that could possibly be wrong, is wrong, and it would be faster and easier to start from scratch. The N6NB Quagi designs cited by Dale earlier are totally excellent, cheap, lightweight and very easy to build. Although Wayne shows plexiglas and shaved 1x2" pine for suitable boom material, bamboo works great also (anything strong, straight and non-conductive) for the 70cm Quagi. One of the great advantages of this design is it has no matching section to create mistuning or loss; it uses a 1-wavelength (approx) directly-fed wire loop as the driven element, period. No other parts involved in the feed system, which is perfect for 70cm, where nearly all materials begin to get lossy. If you build the 70cm Quagi, it might get you excited enough to want to build the 8 element 144 MHz version as well. Properly built and adjusted, that 8 element design has more gain, and a cleaner pattern, than the Cushcraft 13B2 -- all while weighing less and being much less likely to become detuned by weather! Good luck & have fun.