Tower Assembly

Well, it's time for some more tower assembly at the weekend.

The footing has nicely cured and should be ready to take the load of the tower when it is raised.

Unfortunately some more accurate measurements of the position of the eaves stand-off bracket suggest that I'm going to have to have it slightly further out from the house than originally thought, in order to avoid the ridge shingles on the roof, which extend a little further than my original estimate. The more accurate measurements suggest that I might have the tower displaced 6cm or so off true vertical, given where the footing is now laid! While unfortunate, I don't think it should be too bad (6cm in 700+cm will end up inclining the tower a mere half a degree off vertical which I'm sure can be tolerated). Fingers crossed, anyway.

One other odd discovery during the preparations for assembly of the tower is that you don't seem to be able to source pipes for radio masts too easily in North America. The tower will take a 1.5" diameter mast at the top, which unfortunately disqualifies the rather nice 2" aluminium mast I brought with me from the UK 9 years ago. That mast was procured from one of the UK radio equipment vendors and delivered direct to the door. Looking at the online catalogues for the UK radio stores reveals that they continue to sell aluminium mast in various dimensions. However, trying to find such hardware in North America is a different experience, and the advice from most people is "go to a hardware store and get a length of pipe or a fence post"! So, tomorrow I'm off to do just that - cruise one of the biggest hardware stores in Vancouver for anything that might fit.

One more unexpected job regarding the tower has to do with the stand-off bracket. This is made of fairly chunky galvanised steel (I think). It is designed to fit up under the eaves and be fastened to the soffit boards. On my house, the pitch of the roof there is almost exactly 45 degrees, yet the bracket is delivered with the two arms barely off the horizontal. This seems a little odd considering the purpose, and will require that I find a way to twist the metal neatly to the required angle without otherwise putting it out of shape. I've enlisted the help of my neighbour here (who knows a thing or two about working metal), and certainly I'm not equipped with even a sturdy vice in which to anchor the arms to apply the required twist. Hopefully my neighbour will have some ideas and/or tools to get this sorted out. Once this is the right shape, then the bracket can be installed with 8 lag bolts and should be ready to receive the upper reaches of the tower when raised.

Aside from the tower construction, the antenna needs assembling - and hopefully this too will have a good start tomorrow. The full antenna is 9m long with several traps/resonators along its length. There are also two sets of radials. In all probability, I'll work toward having the entire length (from tower, to mast, to antenna) assembled on the ground - sans extras such as radials and feedline. Then, probably next week, I'll do final checks, install the feedline (and strap it to the mast/tower with nylon ties), attach the radials and rig the tower to be raised with some ropes through eyes in the eaves.

The sheer length of the whole contraption, at around 20m, fairly boggles the mind as something that must be lifted to the vertical in a controlled way and then lifted onto the base plate and secured. Still, this is not a large tower in the grand scheme of things, and presumably good preparation and then enough pairs of hands during the raising will be the keys to getting this up safely and effectively. Fingers crossed (again)!