Thanks again, ADTech. That tilt bracket mast clamp is a good design. I will move it to the very top of my new mast, gaining a few more inches height.
I knew enough that the array mounting ought to be balanced and I initially tried to mount the U-support so it was evenly placed about the balance point but there isn't enough room for the rear clamp until the space between the 5th and 6th director. However, attaching there causes interference with the forward clamp so the rear clamp must be moved to between the 6th and 7th director. In order to discover this all the directors really need to be mounted to the boom first.
Since the U-support now is not centered for weight distribution the dandy mast clamp must be adjusted further back on the U-support, which can be done simply by holding the completed array upside down by the U-support until the weight balances in your hand. I would point out that the photos in the instructions show the mast clamp attached to the center of the U-support.
https://drive.google.com/file/d/0BxY...it?usp=sharing
Also, the photo with the inset saying, "Attach cable here" appears to be incorrect. My balun box has the cable connection facing down and the rubber weather boot, without rear hole, was loose in the bag. So the caption surrounding the photo is rather misleading. The balon box also has clips on the side, which made me wonder if something was missing from my kit of parts.
https://drive.google.com/file/d/0BxY...it?usp=sharing
My new 4 1/2 foot long mast sections are RCA branded and are carried by Lowes and Walmart. I didn't realize when I ordered them they were bright gold! My wife is not greatly impressed by this exotic array on our roof and all the others roofs are "clean" from such eye-catchers since most have cable
TV. But GOLD?! Sigh.
@Pete. More advice, thanks!
A stacked array of XG91s - wow! I'll bet the directivity is superb.
About 10 years ago I self-installed my own Dish Network system. Back in the day, Rad Shack carried all sorts of antennas and accessories, tools and so on. I got from them some tape designed for sealing connectors from the elements. It was rubbery and you would stretch it as you wound it around the connector, making an excellent seal. It worked very well. I must see if I can find a source for it.
EDIT: I found it!
Scotch Professional Mastic Electrical Tape. This stuff is wonderful for weather securing F-connectors.
BTW, I have been fiddling with the array - not at full height. I raised the mast briefly to full height and noticed that the tilt angle (9 degrees) seemed higher than necessary. I am not a mechanical genius - and not a math wizz either. So, raising my mast 5 feet higher it seems I should reduce the tilt angle, yes? I don't understand why this is so.
Here is photo of the tilt angle with array just above roof level:
https://drive.google.com/file/d/0BxY...it?usp=sharing