Mayday brought the combination of a day off, plus sunny weather, plus no wind.
Go back two weeks:
I had a first go at hoisting up the 40m dipole. This was initially frustrated by discovering that the heavy winds of the last couple of months, although they had proven that my experimental mast was fairly safe against the wind by itself, had managed to lift the rope off the top pulley. I hadn't realised there was enough room for the rope to slip down the side of the pulley, but the wind had managed it. I had to wait for a hand to get the pole down again. I added a couple of cable ties to the pulley arrangement to stop the rope coming off again, but I can see now that this pulley is not really reliably enough. Note for the future: get a better pulley, probably some sort of marine block and tackle.
I had my 21m length of house wiring wire (2.5 square mm intended for lighting circuits I think, I will check next time it is in reach) and originally planned on making a delta match into 450 ohm feeder. I made a few inquiries, including putting a question on http://www.antennex.com/. After some suggestions from Tim (VK3IM) on this forum I decided instead to cut the dipole at the centre and simply connect the 450 ohm feeder. I gather that this will eventually need tuning at the far end of the feeder, but I understand this could be the basis of a multiband antenna, rather than only working on 40m.
Anyway, I hoisted the centre point, to some alarming bending from the top 2m of 12.7mm (half inch) tubing, but it got to the top okay. I tied off the hoisting rope, and then tied some more rope to each dipole end. The uphill side was easy to tie off to a tree, nearly horizontally due to the slope. I don't have an obvious place to secure the "downhill" end of the dipole, so for now I simply extended out the rope from this dipole end and tied it to a concrete terrace chair. This results in the dipole dropping at about 30 degrees to the horizontal. I will need another pole arrangement for this end eventually.
Then the wind began to build over the next day or two, and the top 2m of the pole was thrashing around a lot, so I lowered the dipole until I came up with a plan.
It occurred to me that the problem with a hoist is that the downward force is twice the weight hoisted, due to the pulley idea. I could reduce this with a multiple pulley arrangement so the tension on the rope is reduced at the expense of a lot more rope! Also I needed some more guy ropes for the top section of the mast.
Back to yesterday. The fine weather tempted me out, and I hoisted the dipole again. The top pulley continued to play up, as although the rope could not actually slip off, any sideways displacement of the weight bearing rope caused to jam, presumably against the cable ties that stopped it coming off the pulley, but I couldn't really see. Luckily I could rotate the main pole to keep the pulley angled directly so the load rope could run up straight.
Once I got the dipole to the top, I was able to use the tension in the lift rope to double as a guy rope by tying it off to the western guy anchor. I put some bend on the top 2m of pole - the prevailing wind is from the west so this should anchor it well. The dipole itself is almost north-south, and I angled the feed line off the house in the east. I realise that I should have tied off the feed wire with some string to relieve the strain on the copper cables. My guess is that this is going to be the weak point.
The photo is taken from the uphill side (north east) so is looking down at the support pole, and shows the south dipole wire tied off to a chair.
Daytime tests into my HF225 receiver showed the usual range of strong Spanish stations, and not much else. Sunset brought in a strong Japanese station in conversation with a number of Spanish amateurs. I swapped to the softrock and couldn't get this signal until I eventually substantially reduced the gain on the A-D converters, which suddenly cleaned up the band. This is odd, as level meters on the converter did not show any peaks, but I suspect these level indicators. At some stage I will experiment more with converters, I am trying out a few 192k converters I have around.
Today we have strong winds again, this unusually from the east. I will watch with interest how my skyhook behaves...
