THE BLURB. The South East Radio Group Newsletter April AREG Visit SERG

Transcription

1 THE BLURB The South East Radio Group Newsletter April 2011 AREG Visit SERG SERG Club Rooms all setup for the presentation from AREG (Photo courtesy Charles VK5HD) It was back on the 4 th of February that 4 members of AREG came to visit SERG and talk about their High Altitude Balloon Experiments and demonstrate some of their equipment. Adrian VK5ZSN, Terry VK5VZI, Matt VK5ZM & Grant VK5GR came down and gave a presentation on Project Horus ( a series of experiments with High Altitude Balloons and the variety of payloads. Terry VK5VZI gave some background on the experiment and described the challenges that they faced and some of the methods they used to overcome them. Topics varied from ways to hack some of the Canon digital cameras to give them new modes to how to build light-weight payloads to problems with launching.

2 Adrian VK5ZSN talked about the Government Sponsored fox hunts that occur when the Bureau of Meteorology (BOM) releases a weather balloon for atmospheric and wind readings. It so happens that Mount Gambier is one of the locations that regularly releases weather balloons and there was hope to monitor a balloon that evening. As it turned out it wasn t to be as the schedule had changed and Mount Gambier no longer releases weather balloons at night. Adrian VK5ZSN in the back of his hunting vehicle View of the computer screen in the back (Photos courtesy Charles VK5HD) For those who were interested there was an invitation to chase a weather balloon due for release the next morning at 09:45 or 23:15 Zulu. The plan was to meet on the roadside near the Bureau of Meteorology and watch from there. As luck would have it someone contacted Craig, the local officer, and we got invited into the site to see the launch up close. Just before launch time the radiosonde from the balloon was detected and signals were being received. Unfortunately the prediction was for this balloon to end up out at sea so there was little point in chasing it. The prediction software was done by Cambridge University and can be accessed via the website

3 Photo of Balloon as it is exiting the automated launch system (Photo courtesy Charles VK5HD) Grant VK5GR has put a video of the radiosonde release up on the website (see project horus reference above.) Tony VK5ZAI was back home in Kingston and was monitoring the launch from his QTH. His 70cm beam was able to pick the signal of the balloon up when it got a bit of height and was still getting data as the balloon passed over the coast and out to sea. AREG s visit certainly generated some interest and they to got take back some surplus equipment that was kindly passed on by Kevin VK5NKJ & Andrew VK5FCLS.

4 From the Webmaster/Editor: Hi Everyone, Well this is the second attempt at a newsletter and I ve had a few good comments about the first one but will always welcome suggestions for content or improvement. This edition has a lot of balloon information in it and not much in the way of other amateur radio topics in it. Please help me to address the balance with suggestions for topics, even an article on something. There was a thank you on the Project Horus website from Grant and the guys which was nice to see. Thanks to Colin VK5DK for putting a short article together on the 23cm Transverter. Thanks also to John VK5DJ for the report on the recent work on the Repeater Network. Andrew VK5KET And now a word from the President. Hello It is good to see the second edition of The Blurb. Let s hope we can get enough information from you to continue to a lot more editions. Well let s get into it. The convention this year looks like it will be a one day event with Ross from Strictly Ham favoring the Sunday. Location and details will be worked out very quickly and advertising to let everyone know of the changes coming soon. So we all know the Fox Hunting Championships will remain a TWO day event. Numbers have increased for this event and we would be silly not to accommodate this increase. Wayne VK5ZX is working on the program and will resemble closely that of last year s program. The clubrooms are for use by you the club members. It was great to hear that Colin VK5HCF was using them for a QRP contest. As time goes on the shack at the club rooms will be more and more populated with equipment for you to use. So think about getting some people together and going to the clubrooms for a bit of fun. Charles VK5HD.

5 Other News Congratulations to Eion VK5KEE and Paula VK5FOXX on the arrival of their second harmonic. Upcoming Events WIA National Field Day Sunday April 17 th Amateur Radio, The first technology based social network Harry Angel Sprint Contest April 23 rd GEO Parks Weekend 28 th /29 th May. For those who are interested the GEO Parks weekend is scheduled for the 28 th & 29 th of May. This year there are some new European stations being active so hopefully conditions will be kind. Australian Foxhunting Championships June 11 th, 12 th Held in conjunction with the SERG Convention the competition is on as usual this year, we will be looking for volunteers to go hide and transmit. SERG Convention 12 th (To be confirmed) Planning to start for the 2011 event which will be the 48 th Convention. Repeater report Tony VK5ZAI reported noise on the link between The Bluff (VK5RMG) and Mt Benson (VK5RKN). Col and John were able to monitor the UHF link on MHz and it was obvious that we had a problem with the transmitter. It sounded as if the Phase Lock Loop was having trouble locking. The 8025/30 transceivers are not designed for full time operation so do run hot. The links at VK5RMG are both 8025s and most of the time are working just as hard as the main transmitter. We reduced the power on the links when we originally installed them to minimize heating. So on Monday 11 th April Col (VK5DK) and John (VK5DJ), after checking with the site owners, set off up the hill. The link was misbehaving when we left home so we hoped that any changes made would show up immediately. Col is the master of the surface mount components so after removing the link from service and removing the covers Col got to work on the electrolytics.

6 Electros have proven to be a problem in the 8030s so Col removed all 6 on the TX board. The very first one he touched with the iron cause Col to say Hm, funny smell, a sure sign. So Col felt he was on track. Apart from muttering wise words John found that one of the removed electros did have a moist dark substance on the base. Among the 6 electros was one that served the mute circuit and as these often fail we hope we have given a new lease on life to the mute as well. After putting the unit back together and hooking up that really difficult to access antenna plug, we made a few test calls and listened to the link. So far so good! While travelling home we worked the unit a bit and Tony joined us reporting that all seemed OK. The big test was the broadcast that night. Fortunately Tony reported that there were no bad sounds coming down the link during the 40 minutes it was active. We hope that the problem is fixed. We have two other problems with the network at present. The Willalooka repeater is down. Allan VK5ZLT has visited the site and found that the power supply has become intermittent. Throwing the power switch several times brought it back to life but it failed again the next day. John VK5DJ is resurrecting a spare power supply from a unit owned by the club and will get this to Allan on Friday. Hopefully Allan will be able to replace the unit as soon as possible. Tony has offered to fix the wayward supply. The other problem is a noise entering the network at Naracoorte. It sounds more like an interfering signal than a fault at the site. We have also noticed that it is worse after a warmish day. Probably someone s mast head amplifier but we are not sure. Simon VK5VST has offered to monitor the input channel and see if he can hear it. Until it is a consistent problem there is no point in the maintenance team visiting Naracoorte. If the interference becomes too bad John will turn off the link to Naracoorte. When this has happened you will notice there is no beep on the tail. John VK5DJ

7 Member Contribution 23cm Transverter Colin VK5DK Recently I have been using a 6 foot Parobolic Dish supplied by Tony VK5ZAI on 23cm (1296MHz) for portable Field Days and have been very impressed by the signals received and transmitted over the previously used 49 element yagi antenna. As the 23cm (1296MHz) equipment used on Field Days was operated from inside our tent with a coax lead to the dish, I decided to get best performance it would be best to operate a unit on the tripod attached to the 6 foot dish. With this in mind I decided to construct a 23cm Transverter which had the same operating controls as all my previously constructed 2.4GHz, 3.4GHz & 5.7GHz Transverters. 23cm Transverter constructed by Colin VK5DK (Photo courtesy of Colin VK5DK) In the designing of the 23cm Transverter I also wanted to make sure that the frequency stability was extremely accurate without drift which had occurred when using a crystal oscillator on previous designs. I had obtained some Qualcomm PLL boards from Alan VK3XPD which were able to be programmed to 1152MHz with a 10MHz reference oscillator enabling me to use an I.F. frequency of 144MHz to produce a 23cm (1296MHz) Rx/Tx signal. Using this system I was also able to use a GPS locked 10MHz frequency for extremely accurate Tx/Rx if needed. I had built a VK5EME Transverter previously, so the 23cm (1296MHz)main Transverter board was again used, but the 1152MHz PLL unit was used in place of the Crystal Oscillator. The PLL section has an on board 10MHz

8 reference oscillator which is very stable, but if extremely good stability and accuracy is required I can plug the Transverter into my 10MHz GPS locked signal. My portable unit is running around 20watts output to a RF Module type RA18H1213GPA and I have also incorporated a receiver pre-amp to maximize receiver performance. This unit was used at The Bluff during the John Moyle Field Day with contacts being made into Melbourne even though radio propagations were not very good. It was also found that using only the 10MHz reference oscillator that signals were extremely stable, so the GPS reference was not used on 23cm. Tech Talk Sondemonitor Due to the interest generated by AREG s visit I downloaded Sondemonitor.exe ( ) and have been trying it out. Firstly for Mount Gambier you should select digital sonde decoding as that is the type released from the Bureau of Meteorology (BOM) This can be done by clicking on the left button of the decoding options. See the picture below. The menu for Sondemonitor the Mode for Mount Gambier s radiosonde is circled in red. You need a radio that can tune in the MHz region on Wideband FM as the audio from this can be decoded via the computer s sound card. The frequency is determine just prior to launch so it can be anywhere, however for Mount Gambier most often it is 402.3MHZ which can be handy if you aren t able to be by the radio for the launch.

9 The launch time for Mount Gambier, at the time of writing is 23:15 UTC. It didn t change when we went off daylight savings so it s probably always at this time UTC. If you don t have the information for GPS or a GPS that you can get the almanac out of you need to download the file from the U.S. Coast Guard. and follow the links to the Almanacs. The file you are after is current.al3. This will allow you to get a GPS fix that is close to actual, it can be offset by a bit though. Sondemonitor does provide the option to go and get the file for you but I couldn t get this option to work, possibly due to a website change by the U.S. Coast Guard. To use this information you need to load the file and you need to give the GPS engine a point of origin. I use the BOM site at the airport as given by Oziexplorer. ( ) To get the GPS position information you also have to ARM the GPS Sondemonitor has a real handy feature called scripting. You can create a script in a file and Sondemonitor will execute the commands as required. The demonstration file shows how to download the updates (I couldn t get it two work), wait for a specific time, load the GPS file, arm the GPS system with a position and it will start decoding. So even if you can t be by the radio and the computer, so long as you can leave them running you can set Sondemonitor to do it in your absence. The example file shows how it actually automatically monitors three different weather balloon launches in the UK. When you do get it running you will get a status screen like the one shown on the right. This displays the various parameters decoded from the radiosonde. When decoding successfully the red dots on the display will be green.

10 Tracks of recent weather balloon launches data converted to view on Oziexplorer Just a comment on the Cambridge University Prediction software. I tried running it on Internet Explorer 8.0 and had some difficulties, the prediction would run but all I got was a black screen instead of the maps. Couldn t figure out why. Tried it on Mozilla Firefox and had no problems. It would seem that Microsoft made some changes to IE8 that makes it less compatible with some sites. Computer Viruses I have had recent encounters with some malware Security Shield is someone s idea of scamming people for money. Various websites have had this software uploaded in the form on an image. When you go to download the image you get more than you bargain for and before you start wondering, it was downloaded from an emoticon site by someone who wanted a smiley face icon. It install itself in such a way that while you re browsing an alert will popup to tell you you are infected with a number of viruses which are all bogus. It then directs you to a website that asks you to pay to get the software to remove it. Unfortunately it also prevents taskmanager from running so you can t easily view what processes are running. It also causes the computer to

11 run slow and interferes with internet explorer and stops a number of other processes. It wasn t picked up by AVG link scanner or AVG antivirus when the disk was scanned independently. There are a few instructions on the web on how to remove it and some freeware tools that detect it but don t guarantee to remove it unless you buy the version. It took quite some time and a number of different freeware packages to clean the system off but it can be done. Finally. Something to make you laugh (I hope).. A fifteen year old Amish boy and his father were in a mall. They were amazed by almost everything they saw, but especially by two shiny, silver walls that could move apart and then slide back together again. The boy asked, 'What is this Father?' The father (never having seen an elevator) responded, 'Son, I have never seen anything like this in my life, I don't know what it is.' While the boy and his father were watching with amazement, a fat old lady in a wheel chair moved up to the moving walls and pressed a button. The walls opened, and the lady rolled between them into a small room. The walls closed and the boy and his father watched the small numbers above the walls light up sequentially. They continued to watch until it reached the last number and then the numbers began to light in the reverse order. Finally the walls opened up again and a gorgeous 24-year-old blond stepped out. The father, not taking his eyes off the young woman, said quietly to his son... 'Go get your Mother'