DiP-M / Alpha testing

Okay, finally got the chance to do some testing on the DiP-M.

The testing setup tonight was the following:

  • Wouxun KG-UVD2P handheld
  • Battery eliminator for the Wouxun
  • Two 7.2Ah 12V batteries.
  • Byonics TinyTrak 4
  • Serial GPS reciever.
  • 12V solar charger 1.5W (125mA)

Much to surprise me, the current drawn with this setup was 223mA, which is to high for the solar charger. I decided to start removing one device at a time and see what the current drop would be. Surprisingly, the small 5V serial GPS receiver drew about 130mA, because the Wouxund and the TT4 only drew around 90mA at standby current!

I did some testing, mounting the DiP-M on the roof of my truck but it’s not good enough to get a good signal to next IGate, so further tests will have to wait until the morning.

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DiP-M, Solar powered APRS Digipeater.

 

Recently, I’ve been more and more interested in APRS. I’ve been doing frequent tests on both 2m and 6m, with fair results. However, an idea has been growing in my mind, to do something to extend the range of the APRS system in Iceland. As of beginning of 2012 we have one high level digipeater in Reykjavik, and two to three smaller ones in Reykjavik and one in Keflavik. There have been plans to expand the range and install a digipeater in Bláfjöll, mountain near Reykjavik which could give a good coverage to the east of Reykjavik, past Hellisheiði.

DiP-M is a mobile digipeater, self powered by solar energy with a huge battery buffer. I went off with few main points that I would want to see it succeed at:

  • Robust
  • Long battery life
  • Long range

To success at these goals, the device would have to be highly energy efficient, low power consumption, strong enclosure, the ability to charge the batteries, and located in a very high spot, i.e. on a high mountain top. I’ve started gathering resources for the basic testing. An almost waterproof box; a not so great 1/4 wave antenna; durable Kenwood TH-25AT ham radio; TNC (which I haven’t still decided what type); 12V car battery with high capacity; and a cheap 1.5W solar charging cell.

I have started the construction of the test box and hopefully will start to execute the tests in the following week. The callsign will be TF2SUT-3 for now. More news in the following days.

 

 

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Skyward Sphere

Okay. The website went down again (router issue) but it’s up again!

Skyward sphere

Anyways, I’ve been working alot on various balloon projects. The prologue to this was that a cooperation project between Reykjavik University (RU), Síminn (Local phone and ISP company) and CCP (The creators of Eve online) decided to launch a balloon into the stratosphere with an Escape POD from Eve. They had some issues tracking the first test launch and decide to google tracking options and came up with APRS, the amateur tracking/messaging system. This is my part of the project, helping them guys out with the Trackuino which they chose for the project and building antennas which could be fitted on to the balloon payload.

One thing lead to another, and suddenly I was highly involved in debugging strange interference issues between SPOT (Satellite tracking system) and the Trackuino as well as other common issues with making antennas that could be fitted onto the balloon’s payload. The second launch which I participated in was quite a success altho’ there were some issues with the cameras and the launch it self, we kind of crashed the payload into the ground at takeoff and some of the cameras got askewed.

The APRS trackuino was a huge success, it tracked the balloon all the way save for the last 3km before landing. That was, what we expected as the only receiver stations were positioned in Reykjavik. TF3ARI, TF3RPF, TF3RPG and TF8TTY were the digipeaters and IGates who operated at that time. We have plans to increase the range by installing more digipeaters and IGates throughout the island.

The SPOT also did it’s job as from it’s position report we were able to locate the exact landing spot. The guys at RU had talked to the helicopter team of  LHG, the national coast guard to retrieve the payload after landing. However, a misunderstanding with GPS coordinates caused the LHG helicopter team to be unsuccessful in retrieving the payload. To be exact our coordinates were in degrees decimal but the national coast guard uses degrees, minutes and seconds. Thankfully, this was only a balloon and not some highly important rescue mission and I’m quite sure that the guys at the LHG have learned something from this, which is a very good thing. Mistakes that we learn from is a very valuable information.

So the first retrieve was a failure, but we decided to try to retrieve the payload early on the Sunday morning. Late on Saturday eve’ I went to my workshop, changed tires on Undanfari II and went home to sleep. Woke up at around 4 O’ clock in the morning and headed to N1 gas station where we had decided to meet up. We were 8 persons on two trucks, Toyota 4Runner 44″ and Benz Gelandewagen 38″.

The payload’s crash site was located in the highlands, which was covered in snow. To be exact it was right north of Sultartangalón on a path called Gljúfurleiti. We had a driveshaft U-joint failure when we were in the valley called Þjórsárdalur. Thankfully, I had a spare U-joint and a friend of mine in the next neighborhood lent us a spare part to fix the drive shaft. Many thanks to the local energy company Landsvirkjun as they were very kind to let us in to their workshop so we could fix Undanfari II.

After an almost 3 hour stop we were able to continue our journey to Gljúfurleiti and as we got further inlands we had to release the air from the tires to be able to float better on top of the snow. As we came to the first river, we had problems passing it, shovels were used and eventually, we managed to break through and get to the other side of it. It was not a big nor deep river, but the ice makes everything more difficult.

Few hours later, and after getting stuck and having to release more tirepressure we finally made it to the payload. And what a surprise! it was friggin’ spot on at the GPS coordinates that the SPOT gave us. We stopped for a while, checking the gear out and it was surprisingly, in a quite good shape. Then we started heading home, as the weather was getting quite furious, but the snow was heavy and we had a long journey. We arrived home around 19:00, quite exhausted.

The data collected in the second launch was valuable, and to a good use. The week after, I, Jón Þóroddur (TF3JA) and Dr. Joseph Foley held a presentation at IRA (Icelandic Radio association) which was quite a success.

The third launch

CCP, RU students and Síminn wanted to do a third launch. Few weeks passed and it was decided to launch it when the weather conditions would get better. Wednesday the 9th of May we decided to launch the third one. I was not much involved with that launch and it was quite a success, streamed live video to a website of CCP dedicated to the launch. The balloon was launched from the Reykjavik harbor and it landed in Kleifarvatn, just south of Reykjavik. This was quite a short flight as the wind conditions were not good. However the retrieve was easy as the payload drifted towards the shore.

Participating in these events have been quite entertaining, educational and have given me a deeper interests in the APRS system. I have plans for other balloon projects this summer and other interesting launches in the fall, so be sure to follow up!

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Wiki síða

Enn ein andvökunóttin, og ég fékk þá flugu í hausinn að henda upp MediaWiki á Frigg. Ég veit ekki alveg afhverju, en það kemur í ljós á næstu dögum. Ég hafði hugsað mér að henda inn gagnlegum hlutum eins og formúlum, upplýsingum um radíódót og annað sem ég nota af og til og þarf að hafa greiðan aðgang að. Síðuna má nálgast hér en DNS færslan á sennilega eftir að detta inn með morgundeginum og verður síðan þá aðgengileg.

Þess má geta að vefsíðan hennar Andreu er komin upp aftur og má nálgast hana hér. Þar má finna ýmsar skemmtilegar myndir, og verður síðan vonandi uppfærð sem oftast. :)

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