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.

The HX Files Xtract 024

Hello and welcome to Xtract 024 of the HX Files.

In this issue I would like to write about some of the templates that were made, and used, to help me in the layout of the parts in some of the projects constructed over the last few years.

Like in any construction project you would layout the various parts to be used in the project to find out not only what goes were but were to drill, file and shape.

When it comes to drilling out the holes and filing them to shape for the final fitting, you would be placing the parts in and out of their positions many times before their final placement, and as a result the parts can get marked, damaged and even broken, and as a result of this, over some time various templates have being made to help me out, see photo 1 below for a few of them beside the actual parts to be used.

Project parts and templates

The easiest to make was the template made for the various amplifiers that have been used, as they are most often mounted on to some heat sink by the manufacturer in its enclosure and this would entail removing one of its lids, and this was a ready made template that could be used for marking out its location.

But when it came to space being a part of the construction a piece of wood was cut to the size of the amp and the lids bonded to the wood, and some small screws and/or panel pins are used to act as their coaxial sockets and DC connections, later on some of the templates had N type sockets and others had the SMA type fitted to them as well as a screw or two, and these screws would act as the DC connections.

The 1.2/2.5 GHZ transmitters are the same size as each other, and like wise, their receiver boards, so only one of each would have to be made.

After sourcing some scrap wood, some marking out and rough cutting of the wood was done first and by using some dowel rod to mimic the phono, aerial and DC sockets. 

Smaller parts like the coaxial relays fuse boards, aerial sockets, and such like would not require a template, but I found parts like the SMA terminated coaxial relay would be on most projects featured in Echo Ireland be fixed internally in the project  and mounted onto, or sandwiched between a couple of suitable heat sinks. The larger N type coaxial relays mostly being used often come with a mounting bracket that can be used as a template for marking out the locations of the aerial sockets, seen on top right in photo 1.

For an item like the TV/monitor it would not be practical to make a template unless you could be guaranteed to be able to get the same size of TV/monitor  every time, as a foot note  a couple of 4 inch (100 mm) monitors are in-stock , but their mounting plates are both completely different from one another. At a recent rally four 6 inch (150 mm) monitors were purchased and these are identical to one another so it will be worth making a template for them. These monitors were used for an ice system (in car entertainment system) and would be originally wrapped around the headrest of the vehicle by their own Velcro straps, but as they could be mounted onto the projects by either fixing some small pieces of angle aluminium to their back, or to make a frame, and for it to be attached to the project first and then to the monitor. Some of the projects made did not have many connecting power or coaxial cables, but of those that require a lot of cabling, a wiring loom would be made. When a wiring loom is needed for a project t a layout of the parts are naturally done first on some paper and then a line drawn from the various part to its switch, LED, power or coaxial point, and then when the case or box to house the project has been found, it is also decided what parts are going were. A piece of wood is cut to the size of the chassis and the various project parts would then be screwed or stuck to the wood. With that completed some screws or nails were added that would act as formers or guides for the various cables to be used in the loom, by simply using some string (in stock, as it is cheaper than the finished cable) to act as the cables, the string would be tied onto the screws on the templates and then the string ran along the board to the other points on its line and then tied off. (This would be repeated until all parts were catered for)  Once you were happy you would transfer each length of string to the appropriate length and rating of cable, and with all the cables now replacing the string they could be bound together with some tape or cable ties. 

As you can see in photo 2 above and on the right, the template of the chassis and front panel have a few holes and screws about their surfaces, these are for the various switches and any other parts that would be attached to the panels.  You maybe able to see the string and the screws making up some of the loom, the piece of string tied to the screw representing the switch and routed along the screws to the fuse point and then to the DC supply, and this you would do until you have everything wired up, there are a few holes in the chassis boards and the ones not in use are covered with a piece of sticky tape or label when starting to wire up the parts to be used.

Bird Watt meter parts   

For some project you may have no other choice but to use the actual parts,(those of you who have a Bird meter need not worry as one was not scraped,I bought the parts of a fellow ham who had bought them off a dealer, so rest assured dear readers a meter did NOT die for this up coming project) as you can see in photo 3 above these parts are being used in a forthcoming  project, the parts are from a Bird Watt meter  and the only part seen other than the meter is the cavity that its slug is located, but that is another story……..

Close up of some of the templates

And finally, I would like to wish you and your family a prosperous New Year,

 and may your signals continue to be P5.

73, Pat.

Hello and welcome to Xtract 023 of the HX Files.

In this xtract I would like to talk about a handy little project that was made a short time ago, its main use is to be a quick setup when first arriving on site, and it would get you on air in a few minutes by using the tripod, a slot aerial and coax you would be on air whilst the main station was being setup.

The unit in receive mode

 In photo 1 above you can see the finished project,
 top is the transmitter, on the left side is the receiver, in the middle is an N type socket, on the middle right is a TX/RX switch, a red and green lights, and a red and black DC sockets. In the lid of the box is a monitor and on the top left of the lid is a camera with sound.

Case history

The case for the project was bought at a nearby car boot sale, it was originally a vanity case and the main reason it was bought was (not for the fiver the seller was asking or the hair dryer in it but) the fact that the lid was deep as it would accommodate a monitor for a project when I got a monitor small enough to fit, and there the case lay, languishing in the stores department, (as seen in the last HX Files) for a couple of years. Maybe some time I will feature the stuff in that department/shed in a future issue when/if I have to take everything out for some stock taking.

The build

The first thing I noticed was that the case had a couple of narrow metal brackets riveted to the sides to form a support for something when the case was brand new. These brackets would be used as a support for the main panel and for a change the panel was cut from some of the mesh sheets that were bought in Friedrichshafen this year. The panel had holes of 8mm in it and after measuring the internal dimensions of the box a piece was cut out with some tin snips and made to fit the case. You would think that having a piece of metal with a couple of hundred holes in it that it would make for an easy time but they were never in the right location but with the snips and some files the parts could be fitted to it, but as the holes were not in line it meant that when cut out the panel had a lot of sharp edges to it, although the panel would be recessed into the case a lot of filing still had to be done which took a while and I was almost sorry I did not pick a piece of solid sheet metal instead. Knowing the case was a small and that the components would be close to each other I could not be to fussy unless I wanted to made my own case, and also having the 12v battery as a primary power source installed in the case, things would be cramped and some compromising would have to be done. With that in mind the laying out of parts followed, and then with the aide of a file one of the holes was widened to the size of the SMA fitting on the TX board, and with a pair of snips some of the metal was removed to let the phono and DC sockets protrude trough the mesh, some fine tuning was done with the use of various files to smooth the edges and to make the parts fit nice and tight.

The same method was to fit the RX board next and most of the rest of the parts were able to be fitted as they were small enough to be installed with no need for the holes to be touched, with the exception of the N type connector the file was used to remove the excesses metal. With the TX/RX boards and other fittings in place, but as the transmitter’s output power was 50mw I decided to use a 2 watt amp, it was connected to the TX unit with a small SMA patch lead on one end of the amp and the previously mentioned N type panel mount to the other end, and as the amp was mounted under the panel, and the transmitter’s SMA fitting was above it, one of the holes in the panel was widened to allow the patch lead through it and connect the transmitter to the amp. The fuse holder was mounted on the top of the panel, as if there was a power issue the fuse could be checked out quickly without the need for a tare down of the unit. The use of the DC sockets are two fold, their primary use are to allow the recharging of the units 12v 5 amp internal battery, and they would also be a handy source of 12v.

Photo 3

 The monitor was attached to the lid of the case with the use of some small brackets to leave a space for the audio to be heard, as the monitors internal speakers were mounted in the back of it, it also had a headphone socket so you could use the headphones or a set of active speakers depending on the location, in photo 3 to the left of the monitor you can see were the camera is fitted.

In use

 To use the transceiver the toggle switch is moved from its centre off position and pulled towards the operator, and to receive the switch is pushed away from the operator from the off position. There is no separate power cut off switch, but this toggle switch has a locking system, to use it you have to lift a spring loaded shaft and move the switch to the position you want, when the shaft is released it locks the switch in that position and it cannot be moved until the shaft is lifted.

Photo 2

 As you can see from photo 2 on the left (a close up of photo 1), a small aerial is attached to the receiver for self monitoring if I decide to leave the unit in TX mode I could use another DC lead and connect the receiver to the DC sockets, to the right of that aerial you can see an SMA to N type adapter that will allow the main aerial to be connected.

In photo 4 below, you can see the kit ready for assembling on site, the aerial used is a slot type and above it is its protective sleeve( removed for the picture) which is made up of a piece of plastic waste pipe.

  When not out and about with this project it can be used as a test piece for checking out other receivers and transmitters like the one featured in issue 08 of the HX Files as seen photo in photo 5 below.

And finally

This project has reminded me that somewhere in the deepest part of the shed is a much larger case so if get brave I will go exploring and locate it.

That’s it for now and may all your signals be P5

73 Pat.