I just completed the process you are about to tackle - installed a new TH11 on a newly installed HDX55 tower. The performance of the TH11 and the crank-up tower are really impressive. Worked about 190 countries in just 4 months. Since you will be doing new construction think about the following:
1) Pick the antenna location ASAP. Keep in mind the TH11 has a 22 ft turning radius. Now is the time to clear any trees that will interfer with the rotation or tilting operation.
2) The foundation for the HDX55 takes over 7 cu yds of cement (5' x 5' x 7'). My foundation took 10 yds. Think about how you will get the 36,000 lbs of concrete to the foundation location. My foundation location was not accessible to the truck and they had to use a Bobcat with two 55 gallon drums on the bucket to haul the concrete (15 trips). foundation work for the antenna
3) Pre-install PVC conduit and ground conductors to the foundation location.
4) Go to the US Tower website and make sure your chosen rotor will fit in the HDX55 - they have a table of which rotors fit in each tower. I used a High Gain Tailtwister. If you plan to use their DCU-1 controller send me an e-mail(WA0CRI@ARRL.NET
) and I will give you some info on how to avoid some problems.
5) The easy way to install your TH11 on the tower is to install only the first section of each element out from the boom. Then mount the assembly onto the tilted-over tower and mast. Install the rest of the element sections on the lower half of the antenna. Tilt the tower up and rotate 180 degrees, lower the tower and install the rest of the elements.