Following last messages , and with AB-105 tower ready to receive new HF antenna , I've dedicated my free time to finnish the assembling of OPTIBEAM OB 13-6 antenna. Having read a lot about this little monster , specially about its infamous unbalance , which means that manufacturer could not locate boom-to-mast-plate at its gravity center (as a matter of fact antenna has a very strange look if center plate is located strictly according assembling manual , between S12 and S15) and rear of the antenna will then be sloping backwards...which eventually will give also lots of trouble for those who do not have an HAZER, telescopic tower or crane to hoist it, which is my case! Remember that this antenna weights somehow 75 kg and has lots of 'wing'...
Knowing this, the manufacturer give an option, which is to locate the Boom-to-mast-plate a little bit to the back between S10 and S17, but considering the critics I've read (and specially PY6GZP description...) I was 'terrified' about to have the antenna completely sloping backwards when hoisting it...
As my tower is located in one corner of my attic (6,5 m x 5,5 m), I could not just simply start the final assembling without assuring that I would have acess to parts of it that could be inacessible, so I got back to my drawing table and made some planning with scale models...not easy for those who dont have enough space! The choosed position should be the one from where the antenna will be hoisted. No doubt about this!
So with the precious help of my good friend Arlindo, CT1EGW and several scaffolding 'borrowed' from a nearby contractor...
Due to the assembling position, front of antenna - then completely assembled with all its elements - was sloping a lot so I had to use 3 jerry cans (about 40 kg) full of water hanging them from the rear part of the boom and then assemble longer elements (reflectors).
