The HX Files Xtract 018

Hello and welcome to xtract 018m of the HX Files.

In this issue a 20 watt transmitter with a built in receiver.

This project would be a unit that would be, not to make little of It, a spare transmitter and receiver, and instead of it being left at home, it was to be brought with the main portable transceiver (see photo I below)

Picture 1,
Photo of main rig

just in case anything happened to the main transmitter or receiver. It would be setup as a transmitter, so if needed it could be used straight away. The receiver could be switched on while the TX was on, but as they have their own aerial sockets I could monitor the TX signal without an aerial being connected to the receive socket. There was a plan A or B at the start, I had thought of plan B of making It a transceiver, and by simply adding a coaxial relay, TX/RX switch, a couple of phono sockets and patch leads it could be done, but I wanted to make this spare as a backup transmitter and to keep it as such, so I will carry on and build it as plan A and leave plan B for some time in the future.

The case for this project started life as a 100 watt 2m amplifier, and no, it was not converted to 23cms, it was however converted to junk by its previous owner. I did not ask how he let all the smoke out, but I was told that it was beyond repair, so as the whole amplifier was a large heat sink and would be very handy to have, a deal was done and it was placed into the stores, and there the amp rested for a couple of years awaiting a renaissance. (Wow that was deep, it must be Christmas).

The first thing I done was to remove the old circuit board and switches, (I forgot to take a photo), with that done the original front and rear panels were use to mark out the holes for the new panels, including a new bottom one, but before any cutting out was to be done to the panels I had to place the other parts on the heat sink to give me an idea on were to drill to attach the amp, transmitter and the receiver.





 In photo 2 on the right, you can see the front panel as a blank on the top, and on the bottom with the holes for the various switches, led’s and a couple of carrying handles that would also act as a guard to protect the front. In photo 3 below left, you can see the parts laid out out in their final position with some of the wiring done, the amp top right and the 50mw driver on the left, the receiver is on the bottom right, also seen is some connecting patch leads.

Photo 3

The amp has some pre drilled holes in its own mounting plate and that with the bonding of the amp to the larger heat sink; the amp was finally attached by marking and drilling straight through the heat sink and using some stainless steel nuts and bolts.

Photo 4 on the left shows the back panel with the amp N type socket on the left, you may notice that the two N sockets are different, one been the fitted socket on the amp and the other one a panel mount N to SMA, I was not going to remove the n type fitting from the amp and attach it to the panel via a small lead or adaptor, so not wanting to remove the N type,  a couple of small pieces of the panel was cut out so it would fit around  the sockets, and as I had not got the harder files to work on the steel , I can make a new and better rear panel.

Photo 5 on the left is a picture of the almost finished front panel; the 3 switches are for the 20 watt amp on/off, the receiver, and the DC on/off. The switches and led’s will be marked out by the labelling machine when I find it. The 6 led’s are used for the following, the DC power, amp on/off, TX on/off, RX on/off, the amp has a feature that has a DC monitor voltage that can also be used to indicate if the amp is on so I will use that one as well, and not ruling out a time in the future that the unit could be turned into a transceiver I had a spare led for displaying the relay. In photo 5 the finished front can be seen installed on the heat sink, the keen (Hungary) eye amongst you may have noticed that the led’s seem to white, but when the voltage is applied to them some of them light red and the rest green.

That is all for this Xtract of the HX Files, and indeed for 2011, I would like to thank you for the kind words when I met you at the rallies over the year, so with that, I wish you a very Happy Christmas, and a prosperous, and P45 free 2012.

May all your signals be P5.

73’s

Pat.

the HX Files 017

The HX files 017.

Hello and welcome to Xtract 017 of the HX Files.

In this issue.

 Photos, of a 10GHz RX and 23cms TX, operating /p on 1296GHz SSB
 and Goodies from Friedrichshafen.
 Last time in the HX Files.
 I mentioned about building the opposite

 of what was built, (23cms RX and 10GHz TX)

This time it would be 10GHz RX, and 23cms TX. You can see in photo 1 on the left  the setup, with the23cms TX on the  botom right and surprise surprise, the 10 GHz RX on the top left. The 10 GHz RX is a modified LNB, not the normal Sky type but one that is finished in wave guide. The aerials used were the same as the other unit, a slot for 23cms and a Horn type for 10GHz. The unit for the time been would be finished with N type fittings and I would use some adapters like the last time so I could use different types of aerials, I know that using any adapters would cause some power loss but I was not worried by this as I was not making a DX Beacon I was only going to use it from the bottom of my garden which is around 17mts long. The aerial for the 1.2GHz is a dummy load that can be seen in photo 2 below eft.

 I found that this aerial was good enough to do the job of reaching me.  This TX/RX would be easy (ish) to build in the small box like the last one, but unlike it this unit would not be the handy portable or demo unit as the kit would also involve an analogue satellite RX. So the signal would picked up by the RX aerial first and then via the transition to the LNB, and then down to the Sat RX and then back up to the 23cms TX, the cables used would be some coaxial cable from the LNB to the Sat RX, and from the Sat RX the audio and video would be sent up some phono leads to the 23cms TX, and a DC lead for the TX. The marking out and drilling of the box would not be too much of a struggle as the holes I needed were near to the sizes I had drill bits for and would only involve having to do a minimal amount of filing and run the risk of oval holes, I don’t have a large enough reamer for the job but the files would do as long as I took my time as the box was very easy to file and the holes could get bigger all to quick.

 Oops.

I made a chassis template from a cereal box first and then I would  transferred it on to a piece of clear Perspex and then drill out the holes and file the corners for a better fit, but on drilling the second last hole in the Perspex it cracked and snapped in two, and that was followed by words like gosh darn and blast which could be heard coming from the machine shop (the kitchen) I had no more of the Perspex so I used some hardboard instead, but this chassis would only be for testing and would not be a permanent solution as the hardboard would attract moisture and not only fall apart but short out the equipment as I did not use big spacers and if  the chassis did warp it would short out the TX board  and that would not be a good thing. When I was marking out the box I was wondering how to install the LNB, I noticed that at the F connector was at the back of the LNB and that its retaining nut was on the outside, which meant the nut could be used to hold the LNB firmly to the project box and by using the waveguide to SMA adapter and a SMA to N type that was chassis mount would hold the other end and as you may have notice in photo 3 below left, the F and N terminals are close together.

Some UHF Qso’s.

I had a few SSB contacts on 1.2GHz; yes I took some time away from ATV (WHAT!!!) I went /P with Dundalk Amateur Radio Society (EI 7 DAR ) who took part in the VHF/UHF Field day that took place on the weekend of the 2^nd  and 3^rd  of July. For the 1.2 GHz part of the field day, EI 7 DAR/P was manned by myself and Mark EI 9 FX, and we were using an Icom 910 (2m, 70cms and 23cms), and a 35 element Tonna. Most of the contacts on 23 cms were on the Saturday, and we only heard the same stations again on the Sunday, other members of EI 7 DAR were on 6m,4m and 2meters,  and the 2m crew scored well, they used the callsign EI 0 W/P, anyway enough of that mode.

Friedrichshafen Rally.

The rally was a good one, although the stalls were down the stuff was there, and even if you are a youngster (a pup) or a senior citizen (a grave dodger) you could have bought everything from a microphone to an aerial, and all in-between. At the rally I purchased a few goodies for 23cms and 10 GHz. The biggest was a 60 watt amp for 23cms, and a 2 watt amp to act as a driver for the 60 watt. The QRO amp uses 28 volts+/-, so a 24 volt PSU was also purchased and the one I bought had a adjustment pot fitted to the front, and under test the no load voltage was 27.8 volts and under load (a couple of 12 volt car headlight bulbs in series) dropped this to 27.5 volts and this was well within the amps parameters so I should be getting very close to full power when driven by the 2 watts. I will have to dig deep into the stock piles to look for a suitable project box. I hope to have the unit built soon and have it in the HX files in a couple of issues time if all goes to plan, and the plan is to build it primarily as a base unit, but I could use it /p. even if the main power for the transceiver is 24 volts, I would use an inverter to convert the DC power up to mains voltage, or you could purchase one of the small Lidl/Aldi generators.

That is it for this issue of Echo Ireland, see you next time and may all your reports be P5.

73’s Pat.      

The HX Files 016.

Hello and welcome to Xtract 16 of the HX Files.

Some brain storming.

During a tea drinking session with Tony (EI 4 DIB) one topic that came up was what to do when you want to test a receiver or a transmitter and there is nobody around to receive a signal from or indeed to send one to.

So not living on top of a mountain I would have no DX stations to lookout for, so the talk came around to a project consisting of a receiver on one band and a transmitter on another. So after more tea (and a visit to the bathroom)

 it was decided that a visit to a couple of my stock locations was called for, to see what parts I had that could be used and would not run the risk of been used for another project.

A Hunting I will go.

After a couple of hours hunting for the parts in my stock stash’s, (shed number 2 and under the bed) and a spot of stocktaking, I decided that a 1.2 GHz receiver and a 10 GHz transmitter would be the frequencies of choice.

 In photo 1 above, with the exceptions of some phono and DC power leads, you can see the parts that would be used in the project. The finished project would be used to receive a 1.2 GHz signal and then that signal would be re-transmitted on 10 GHz. The receiver’s audio and video signal would go direct from the 1.2 GHz to the audio/video inputs of the 10GHz transmitter. The project box used is one of the waterproof ABS type so that I would have piece of mind when or if it ever rained The first thing I done was to do a parts layout in the box to see what would go were, not just the TX and RX, but smaller parts like the cables use for carrying the voltage, audio and video, a DC distribution bar, fuse holders and aerial sockets.  The mounting hardware was bolted through the box and a good quality sealer used to prevent water ingress. A sub chassis was used to secure the various parts so that if I had work on the unit it could be removed easily (ish). So after some measuring and marking (photo 2 below) I cut an opening in one of the side of the box, this opening is the size of the aperture of the solfen head .I would attach the 10GHz on one end of the box and the N type socket on the opposite end of the same size.

 I attached the solfen head to the inside of the box and a small extension piece of waveguide that can be seen in photo 1, with that piece having one flange with threaded holes and the other without the thread . I screwed the unthreaded end to the solfen head and the other end of the extension with the thread would be a lot easier than using small nuts and bolts. I could also quickly attach and remove various aerials for testing and some other fittings, such as a slot aerial, a horn type aerial, even a transition from waveguide to a SMA or N type and most importantly, some attenuators to minimize the RF output, so I would get a better test from a weak signal as what was the point of putting out a QRO signal when QRPP was what I wanted to test the receiver’s, and also, I did not want to “nuke” myself. It would be attached to the fence at the bottom of my garden about 53ft from the shack with some attenuators fitted. If I decided to use this project out and about portable it would not be a big deal to undo it.
Photo 3 below shows the unit before the spaghetti ( the wiring) was added.
 photo 4 below,shows the aerials I would use when the unit was up and running ,the aerial on top is a 23cms slot aerial that is covered with heat shrink, on the bottom left of the picture is a slot aerial and on the right is a horn type aerial both for  10GHz.

Testing, Testing.

Tony’s back garden is 100ft long and it was used for some testing of the finished unit, using a rubber duck type aerial with an adapter for the receiving the 1.2GHz signal and the slot aerial for10 GHz. So using a 1.2 GHZ TX, and a modified LNB and an analogue satellite receiver for 10 GHz receiving, the testing was carried out and all went well,

With all the test carried out and passed, the kettle was put on and the tea drank, later on that night at home I decided to make a mod to the unit, I used 2 long leads, one end of each lead was joined to each of the rx/tx units and those leads were joined by a back to back phono plug joiners. The reason for this was that if I brought it to another ham’s shack the system would be mounted on their mast and with the joiner inside their shack the operator could remove the joiner and connect a camera and then he or she would be transmitting on 10GHz, also by connecting a TV on the other lead you would be receiving 1.2GHz. Not exactly what one would call hi-tech, but it works and it may also get another ham onto the microwave bands and that has to be a good thing.

As a result of the testing of this project I decided to make one the other way around 1.2 GHZ TX and 10 GHz RX. I will have some photos of that next time.

That’s all for this Xtract, and I hope all your signals are P5.

73’s Pat.