Friday, May 3, 2013

The HX Files 025



Hello and welcome to Xtract 025 of the HX files.
In this Xtract I would like to talk about a couple additions made to one of the 10 GHz dishes used when out portable.
This would involve somehow attaching a block of metal to the back of one of the dishes. The metal would be shaped to the same profile as the dish and it would have a telescopic sight and a laser fitted to it.
These attachments would (I hope) help me line up with the other station in the qsl  The telescopic sight to help line up the other station, and the laser would hit the spot of their location or at least very close to it.
New toy
Before talking about the project in this issue of Echo Ireland, I was wondering what project was going to finish first as I was moving from one project to another as the stock pile was missing a few parts for some of them, and not wanting to remove parts from other projects made in earlier issues what was one to do, then just what I needed, a new project came to the top of the list that pushed the others to the back burner; I decided to change my car. I had a friend looking out for a car for me and in the last couple of days of February he found what I was looking for and a new toy was bought. One job was to take the radios out of the other car and into the new car, (new to me that is) the ATV gear had to be removed and installed also, although not fully installed into the car yet, some of the ATV equipment is in place and just waiting to be connected, as with some cars there are not too many hiding places to place the parts, and it is getting harder to get cables from the car battery to your equipment. For now only one hole was drilled in the roof for the 2m/70cms aerial and now it is a waiting game to see if a tow bar or a roof rack is purchased to attach anything else. Play time was brought to an abrupt end when our editor let it be known that the deadline was only a couple of days away as I had not noticed the time, so words like gosh and darn were uttered and something had to be finished for Echo Ireland.  
The sight








The telescopic sight (photo 1 above) was bought at a rally in the UK, the trader who I know for many years said that I had the wrong accent to be buying this sort of thing over hear, he did not know what to think when I asked him if he had anything to go under the sight ( a rifle).
Some details
The sight is to be mounted above the centre of the dish, and the laser is mounted below the sight.
Lining up the sight and laser would not require any high tech equipment, the high-tech thing done in a friends yard was to fire the laser (switch it on) at the wall, mark that spot on the wall with a felt pen, and then using a spirit level I marked a spot on the wall the same distance as the sight is mounted above the dish centre, so in theory the spot on the wall would show were the rf is heading for.
Anyway back to the start of the construction, using a piece of wood a template was cut out to match the metal, firstly using a fret saw and then finishing it off with some files and sandpaper to get it right. With that job done it was time to get the shape marked out onto a piece of metal fit enough for the job.
After a bit of a search the block of aluminium (photo 2 below  ) was found in the parts bin, and the wooden template traced onto the metal block.


 Using a small angle grinder, fitted with a cutting disk, a lot of the unwanted metal was removed and the cutting disk replaced with a grinding disk, this would remove most of the metal and leave a small amount to be filed to the final shape.
Ooops
It was while grinding the last of the metal that some of the aluminium dust was sucked into the grinder through the cooling ducts and in an instant the dust ignited and there was a flash and the mains power tripped.
When the power was turned back on I found out two things, one that the grinder no longer worked as the aluminium dust had gotten into the workings of the grinder and wielded to them, and two, new underwear needed.
 It was while grinding the metal that the dust was hitting the guard behind the vice and unknown to me, some of it was bouncing back towards the grinder and being sucked into its cooling ducts.
With the curve finally right some grooves were cut into both sides of the top of the block so that the sight would slide onto the block of metal for fitting. The laser was to be clamped to the block using some fittings from another project until some were made for it, but the drill bit jammed, snapped and followed by the drill with me holding it and the metal fitting broke. So some changes had to be made for this issue, and not having  similar brackets in stock yet, I am just using the smaller laser, or as the trader said, it is an astronomy aide,  When the bracket was finished it had to be attached to the dish but how, not wanting to drill any holes into the dish or the wave guide  after a chat in one of my local hardware stores with members of the staff some adhesive was used and that adhesive is so strong that you would bend the dish rather than break its hold on the parts.


















 As you can see in photo 3 above, there is a difference in the sizes of the lasers;
 the larger of the two is from an old laser printer/copier.



























 Photo 4 above shows the sight in position and the laser just placed on top of the wave guide,
  it or the larger one will be attached to the plate when the parts are got.
  That’s it for this issue; may your signals be P5.
 73 de Pat.