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.

The HX Files 22

Hello and welcome to Xtract 22 of the HX Files.

As I wright this Xtract of the HX Files it is only a few weeks from
 the Friedrichshafen rally in Germany,

 some more goodies were bought and added to the stock pile (the shed)
 see photo1below.

One of the stores department

                                 Some of the stock to be used in upcoming issues of the HX Files featured in
 Echo Ireland, the journal of the Irish Radio Transmitters Society ( I.R.T.S.),

No doubt some items will come in handy, I hope. (Will I ever learn)?
As you can see from photo 1,
 I might need a new stores shed, but what is a man (hoarder) to do
 as it is very handy to have things in stock and not waiting a couple of weeks for the postman.

Not all ATV (shock and horror)

Just like this time last year, I took part in the I.R.T.S. v/uhf field day, the stations were set up and manned by the Dundalk ARS, (EI7DAR) Dundalk went /p in Colon Co, Louth in io63qs. The 23cms ssb and 70cms stations were setup in the back of Marks (EI9FX) van, the 23cms station was an Icom 910 transceiver, and a single 35el beam, the 70cms setup was a Kenwood TS2000 and a single 18el beam. Electricity was supplied by Marks 3.3kv generator, with the radios and a couple of desk lamps only using up a few watts that left more than enough power to use the most important piece of equipment that was brought to 

Slibh Bragh (our location) the electric kettle .

In photo 2 above you can see Marks rotator which is turned by pulling on the rope to turn the beam, not having a direction indicator in the shack was not much of a hardship as all that had to be done was to use the compass to make sure the beam was pointing near enough to the other station and then some fine tuning to lock-on to them, but it did mean that when the aerials were to be turned someone had to get out of the van with their wetsuit on, yes it was that wet for a time one could say that the ground was flooded.

Bits and Pieces

In photo 3 above, you can see some of the bits and pieces bought in Germany, a couple of centre feeds for some 24 Ghz dishes, also seen are some transitions that will convert the waveguide to sma, an a circulator all for 24 Ghz, a couple of items for 5.7 Ghz, a few panel mount N type sockets with various lengths of coaxial cable terminated with a sma fitting on the other end. The mesh sheets seen in photo 1 will be used for some chassis work and maybe even a front panel or two. With a few projects on the go at the same time, the one described below was the nearest to completion for this journal, and as most of the parts were to hand and no need to dig my way in and out of the shed it also needed the least amount of chassis bashing to be completed I decided to finish it first.

10 GHz Transceiver

The project in this Echo Ireland is reusing an old test/QRP 10 GHz transmitter that I have for a while, but to do anything with it I found that its enclosure was just big enough for the transmitter and the modulator board and no room for any major improvements to it. 

10 GHz transceiver

The bottom of the unit you see in Photo 4 above, is of an old security camera enclosure bought at a car boot sale and it is a good size and would be more than big enough to take the old transmitter and even a receiver and circulator so it now would become a transceiver. After a bit of seeing what went where, the first job was to remove the glass pane that was bonded to the front (some of the ingredients used in the manufacturing of glass would distort/block the signal passing through it), so the kettle was boiled (sadly not to make tea) and with the use of the kitchen sink the water was added slowly over the front of the housing and left to soak for a couple of moments to soften the glue. Using a bit of pressure from my thumbs on the glass a gap started to appear and with the use of a small flat metal ruler as a leaver the glass was removed in one piece, the glass was then used as a template to mark out a piece of Perspex which was then glued in.

 A small chassis was made out of some mesh sheeting, and it was found that some of the holes matched up with the mounting holes in the base of the camera housing, those that were slightly out of line were made slightly wider by the use of a tapered reamer, and with that job done the parts were bolted into place on it. The solfen head was bolted to one side of the circulator and the Lnb on one of the other ones. The LNB “slot” is smaller than the ones in the circulator “slot” and a waveguide adapter was used to connect them together, this was done firstly by drilling some holes in the adapter plate to match the holes on the other parts, both parts have threaded holes and could be screwed together, but the makeup of the circulator meant that the heads of the bolts to be used would not allow them to be screwed in straight, so off with their heads and a slot was cut into the top of them so that a small flat headed screwdriver could be used, the screwdriver was small enough to pass through the circulator from the solfen head side and the  bolts could be tightened. The Gunnmode 4 board was first attached to a chassis and then the Horne type aerial bolted above that. To use the transmitter I simply switch it on and off directly from the PSU (as there is no tx/rx switching unit) audio and video leads run into the transmitter from a camcorder, and to receive a signal I use an old analogue satellite receiver with a length of coax connecting the satellite receiver to the LNB and as a result I can monitor my tx signal whilst transmitting, and turning the tx off I can look for other signals.  The finished transceiver was attached to a pole pointing down my back yard and I will be able to use it to checkout any other 10 GHz transmitters and LNB’s I may be working on.

Finally, may all your signals be P5,  73,s de Pat.

HX Files 021

Hello and welcome to xtract 021 of the HX Files.

What to do

After making a few transceivers for use at home or portable, I was wondering what to make next? I was thinking what else would be of use, a beam or a vertical either one of them would be handy to have in the spares department, for the vertical aerial which typically is a slot type would involve some tools that I do not have in my workshop, so I decided that a beam it was is to be. While looking for designs of beams on the net I noticed that some of them were like the ones I have myself but only bigger, that was not the only thing bigger than  I have that I saw on the net ( towers , cars and of course an aerial). Some of the aerial designs were rather complicated to try as a first time project, but deciding  on the designs that were like my own was not a hard choice to make  so I had a look at the ones I use and decided to extend a couple of them. The conventional type of beam was not too bad to make as most of the basic parts were in stock, originally it was a 35el Tonna and now it is a 42el instead.  I already have a 55el at my home location but that aerial has two support arms underneath it I did not go to that trouble as I had not got enough of the tubing for the supporting framework. Working on that aerial was not too bad as a piece of box tubing the same size was in stock as was some of the standoff brackets for the elements. A couple of copper brazing rods were bought and a constructing we went. Having a ready made aerial was great as I could copy the extra piece of the beam that was to be attached to the 35el aerial. The elements were cut using a small hacksaw with the rod being held in a vice, the elements  were not all the same length  but there were a few of each that were the same size, and again having something to copy from was very handy but I still had to make sure that my markings and cuttings were exact. With that job done I had only to place the elements into their standoff brackets and make sure that the same amount of element was visible either side of the bracket. The new standoff brackets were bought at a rally some time ago for spares just in case some of the original ones were damaged. The brackets simply just clicked onto the boom, the original brackets had a small bump on them that fitted into a dimple on the boom which gave them the correct distance apart, the new ones had no bump on them and neither was there any dimples on the new section of boom but they were a tighter fit and seemed to offer a lot of resistance when I tried to move them, the distance of the extra elements were all the same as only the first few on the original beam had a different gap so I made a spacer out of a scrap piece of angle wood to match the gap between the elements .The other beam was originally a 15el loop aerial, and just like the other aerial, from element 4^th  to the last one were the same distance apart and the same diameter of loop. Copying the loops meant using some sort of a former to wrap the wire around to make the loops. As luck would have it I had a large diameter hole cutter (Photo 1 below) that was the same size as the loop, with only what to use to make the loop elements out of being the next issue. After a quick look through the store bunkers I found some rods and whips (I found them beside the fluffy handcuffs but that’s another story) that I could use for something to make the loops with. I was thinking of the odd lengths from some off-cuts of old and scraped aerials I had and also though of brazing/wielding rods, and even the loop of metal that is on the back of the hub caps found on some cars,  keep an eye on the side of the road, as with the one or two pot holes that are around the country have the habit of removing the odd hub cap, this wire is can also be used but it is rather rigid and springy  to bend around the loop former and some of them are of a different gauge of metal . The other lengths of rods and whips were also found to be rather stiff to work with and a bit springy, after a couple of close calls when the rods slipped from my hands and in one case hit the safety glasses I had on.

Time for Tea

It was then decided that the construction could wait and it was time to have a cup of tea or two and think of a plan B. During the tea drinking I was looking for something else and though of some electrical cable that comes in single strand, but of all the different cables I had none were single strand, a visit to Tony EI6IK and he had what I needed so after removing the outer plastic covering I used the electrical cable and wound it around the former, it started to look like a spring and after enough coils were wound on it the wire was cut and I had the loops that I needed for the job also seen in Photo 1 below.

The hole cutter partially embedded in a piece of wood for safety  

The elements before tiding up and soldering to bolts

 Photo 2 above shows some of the loops as each loop were cut off the spring like winding and the ends will be tidied up with a file. With the loops formed you then have to join the ends, this was done by brazing them together; the brazing was done for me by Kevin EI5JG, the two ends of the loop were joined together at the same time in the slot of a brass screw that a screwdriver slot in them. As mentioned earlier this job was extending the length of the aerial, and as the diameter of each element and their spacing was the same between each loop from the 5^th to the 101^st, whilst the strength of the new loops may not be the same as the original elements but they are good enough as they would be only used in a portable setup. A template was made that would help with marking and drilling the holes..

Worktop joiner

End profile of joiner, in the middle,and the two booms

 The template (Photo 3 above left) was made from a joiner used in joining kitchen worktops together, it has 3 holes in it from the manufacture one of these holes can be seen by the square drawn around it, but so far they have not caused any problems. 

In photo 4 above right, you may notice the joiner has a right angle on one side and a curve on the other side of it, the curved side will sit perfectly on round boom if I ever have to extend a round boom aerial. The old and the new extension booms  are 16mm x 16mm and were joined by some round tubing that was held in place by bolts on the original beam and rivets on the new section, the bolts can be removed easily  both for transporting and for the times that a big aerial is not needed. The first hole in this template would bolt into the last one of the original holes and the other holes used to line up, and then to mark (with the aide of a centre punch) the new holes onto the new piece of boom, and then the template removed and placed onto the last of the new holes and repeated until all the holes marked out that are needed. When installing the new elements the head of the bolt that the loop is brazed to can be held carefully by hand and the loop held parallel to the other elements while the retaining nut is tightened. I was lucky that on the second aerial being modded that a hole cutter I had was the right size.

The  new elements 

 In Photo 5 above you can see both the new elements ready for fitting; since the modded aerials were made I have used them on a few portable events and have noticed no difference in Rx and TX signals when I compared them to the factory ones of the same size.Whilst making the loop elements out of the copper wire I did notice that they were not as strong as the original loops and if the birds decided to rest on them the elements would bend and twist as the birds took off from them, so I decided to use the aerial upside down, it may give a better area for the birds but at least the elements would be okay.

And finally, thanks again to Kevin EI5JG for doing the brazing for me, and to Tony EI6IK for the element wire.

And may all your signals be P5.

The new boom before being cut to the required length