[P7] It's all in the detail.

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A fresh search of the shed found a pot of assorted plastic pipe clips. I really ought to add more storage space for glass jars. Just to avoid having so many things sitting invisible and forgotten in stacked boxes on racking.

There were several unused 12mm clips so I immediately replaced the strip metal clamps on the dish. The angles of the arms in the clips were still just a little awry. So I drilled out some small rubber tap washers and placed these over the screws between the clips and the boss. This allowed the clips to settle firmly onto the pipes with the rubber taking up any variation on angle  between the feed boss and the clips. Ideally I need some wedge shaped washers. The sort of thing found on some bicycle brakes might do. Once I decide what I intend to do in the long term I will replace the present, overlong screws with shorter stainless steel ones. 

Now I was able to remove the short studs at the rim, arm support brackets. Since I no longer needed any adjustment there. I was now able to use the short stainless steel, hex head screws and expansion sleeves as originally planned. Though I will need new Fischer expansion sleeves if I intended to add smarter arms.

All focus adjustment now takes place at the pipe clips. They really do hold incredibly tightly! Requiring considerable finger strength to slide them along the feed support arms. The head assembly is now much tidier and solidly secure against random movement. Once I find the optimum focal distance for the feedhorn I could drill through the arms and secure the clips permanently.

A standard rubber boot slid nicely over the base of the Inverto LNB to keep moisture away from the coax F-plug. I also taped the cable to the lower support arm to keep things neat.

Jobs still to do include longer pole clamping screws. To enable a solid purchase on the smaller 70mm pipe. Except that I don't have any handy in that size. Particularly in hot galvanized or stainless steel. Another trip to a DIY superstore will provide these. Then I can fix the dish accurately on that recalcitrant satellite. A suitable packing piece will give the rest of the screws something solid to work against. Where one of the four welded on nuts has stripped its thread. Much easier than finding a welder to add a new nut to the galvanized mounting sleeve. With all the attendant problems of disfiguring rust and toxic fumes.

I also want to clearly mark the centre of the dish to speed up alignment. A piece of electrical tape will do for the moment. It is far too cold and windy to spray paint.

A flange on my focus checking spacer pipe would be handy to ensure the feedhorn is pointing at the centre of the dish. The flange will sit true on the dish surface during alignment checking rather than wobbling about on its 2" diameter. Though it will need a perfectly straight spacer tube to work as intended. A tube to sit in the outer scalar ring with a long pointer for feedhorn alignment on the centre of the dish makes even better sense!

It's odd how much smaller the dish looks in profile and even from behind compared with the view from the front. The boundary hedge is winter bare at the moment. So the dish will disappear more once the hedge is in full leaf. If the dish proves itself on the target satellite I might even consider a lower stand. Just moving it back, or resiting it completely, would reduce its visual impact. The high output LNB would allow a longer cable. Rather than its present situation as close as possible to the house.

Click on any image for an enlargement.

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