This weekend we did the job I have been fearing the most of all. I don’t like climbing in the vertical at all, since its guyed with ropes and very high it moves around A LOT. So we guyed it at two levels with wire to make it a bit more steady but my plan of putting up two more tower sections failed since it just didn’t feel good. So instead we put up one more section with a 9m long tube attached to it. Its half of a 40m yagi director which is attached along the tower section. We hoisted the whole thing as it was, to avoid needing to climb up and raise the top tube. It went pretty smoothly even though we had to abort one lift because of some bad planning.
I don’t know at all if the top tube will survive high wind. We saw last year on our tube which was even longer (14m) that it survived the winds pretty well except that the long guy wires were more creating trouble than actually helping the tube. Unfortunately that tube broke because of a bad joint between two 60mm tubes, which was made way too weak. It was taken from some old vertical and I did not check how well that joint was made, apparently a mistake. So I though that if an element survives on a 40m yagi which is higher up and with also horizontal load it should be possible to hold also as a vertical. But I might be thinking all wrong and it might snap.
So SM2LIY came up with the idea of attaching a cable from the top of the top tower section and in case of failure of the top tube we can just pull that line out and attach it in a tree and we have an INV L. This is just done as a backup plan if something happens in the winter.
I hope I never need to climb that tower again, because its very scary when it moves around so much, so lets keep our fingers crossed that our thinking has been correct.
So left to do when it comes to antenna work for the autumn is to put up the low 6el for 15m to make it a 6/6 stack and to put up the 4-SQ for 40m. So the late autumn and beginning of the winter will probably be spent on making room for the 40m rotatable tower, I doubt we will have it up this year but we will try to make as much as possible done so we can put it up early next year.
I also hooked up the control cables for the BPFs to the openASC box so now the station is almost ready for serious contesting! I took some pictures as well of how it looks now, the SO2R position at least.
Tnx to SE2T, SM2LIY and SM2XJP for the help during the weekend!
Posted under Tower work, Work weekend
This post was written by sm2wmv on August 29, 2010
