November 22, 2017

So many projects, so little time...

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So many projects, so little time... Most of you hams out there reading this probably know exactly what I mean. I currently have so many amateur radio related plans, ideas, and projects in mind, that I just don't know where to begin. Trying to give it all some structure, and to have an easy way to link to related webpages, I've made a list here of all the projects that are in the PA7MDJ "pipeline". I know myself, and probably not all projects will be finished or realized, but some of them definitely will! Suggestions, hints, and tips are very welcome of course. The information on this blog will be constantly edited, links and other information is continuously being added.

Launching a High Altitude Balloon with a HF WSPR tracker payload
This is my main project at the moment. I'm awaiting the special QRP Labs U3B balloon WSPR tracker to become available. QRP Labs currently still has the U3B in its test and development stage. At present the exact date of the U3B becoming available is unknown. Another blog post that I wrote earlier about the U3B, can be found here.
I've already acquired the needed 36" foil balloons (I'm planning on flying the lightweight payload on a single balloon), 0.1 and 0.2 mm enameled copper wire for the dipole antenna, and 52x19 mm and 39x19 mm solar cells, 100 of each. The solar cells are rated average 0.5 V / 300 mA / 160 mW and 0.5 V / 240 mA / 120 mW respectively. It will take about 6 cells to power the U3B.

Some things still to do: buy a bottle of helium, buy 0.8 mm enameled copper wire, buy a precision electronic weighing scale accurate to 0.01 gramms

An interesting forum with lots of info on WSPR balloons is http://radio-signals.com.

Powering up my U3S transmitter with solar cells
While awaiting the U3B, and since I got plenty of them, to get more experience and more knowledge of the little solar cells described above, I've taken up the plan to try powering up my U3S transmitter here down on earth using these same little solar cells. The U3S has to be powered with 5 V and draws about 110 mA at idle and 220 mA when transmitting, so it will require some more cells than the U3B. Soldering to the cells, I've been told, is not easy. I'm awaiting the arrival of a package with special tinned wire strip and a flux pen. Once arrived I can start soldering to the solar cells. The soldering experience I will gain during this project will be invaluable for the U3B balloon project.
I have several circuit designs in mind including the following components, either individually or a combination of them: 5.5 V 1 F supercapacitor, a 5 V LDO regulator, a DC-DC boost regulator, a 3.7 V 100 mAh LIPO battery.
I'm still learning about solar cell specific things like Isc,Voc, Imp, Vmp, and the solar cell I-V curve (see links below).

Some things still to do: buy schottky diodes

http://forum.solar-electric.com/discussion/18083/voc-vmp-imp-isc-explained/
http://www.kg4cyx.net/solar-panel-specifications-explained/

Building a Pixie CW QRP transmitter and an electronic keyer based on Arduino
I already bought the Pixie kit back in the summer at HAM RADIO 2017 in Friedrichshafen. An earlier blog post I wrote about it can be found here. There you can also read about the Arduino based electronic keyer I want to build so that I can use the Pixie with a dual paddle.

I recently made a 40m CW contact with my SOTA friend Roger F5LKW on SOTA F/AM-680. During this SOTA activation Roger used a Pixie transmitter. The CW signal sounded very clear, and if I didn't know better, I would have thought it was coming from one of the more expensive rigs usually used on SOTA activations. This definitely sparked the urge for me to finally start assembling the Pixie kit.

PA7MDJ in the log of F5LKW/P SOTA F/AM-680.
Building a simple QRP magnetic loop antenna and participating in the QRSS beacon annual New Year's Eve Operation Celebration
I would like to build a big (5 to 6 m circumference) QRP magnetic loop antenna of RG213 coaxial cable to use with my QRP Labs U3S transmitter. I hope the mag loop will have enough efficiency to put out decent enough signals on 40m. I secretly hope it still has enough efficiency on 80m as well, and I will experiment on that band as well.

I will use a variable tuning capacitor taken from a never finished antenna tuner project that I bought from a fellow ham at the local club some time ago. The air gaps between the capacitor's vanes is probably big enough for the antenna to handle up to 5 - 10 Watts. So maybe beside using it with my U3S, I can also use it in the field with my FT-817.

If finished in time, I would like to try sending QRSS beacons with my U3S on 30 or 40m with it during the recently announced annual New Year's Eve Operation Celebration.

Some things still to do: buying two 2 metre long planks to build a cross support frame

http://www.g4ilo.com/wonder-loop.html
https://rsars.files.wordpress.com/2013/01/simple-rg213-hf-loop-30m-15m-g8ode-iss-1-31.pdf
https://sites.google.com/site/g7aqkhamradio/home/my-qrss-beacon
https://americanhoplite.wordpress.com/2016/07/01/my-experience-so-far-with-the-mfj-9232-loop-tuner/
https://www.nonstopsystems.com/radio/frank_radio_antenna_magloop-small.htm

Building a magnetometer
I've always wanted to build a magnetometer to experiment with taking my own measurements of the activity of the geomagnetic field at my own QTH.
You can build one easily with a jam jar and a light or laser pointed at a mirror on a suspended bar magnet, but I prefer another similar design by GJ4ICD which uses a Hall effect sensor instead of the mirror/light like presented at the UKSMG site here and linked to below. Unfortunately the Hall effect sensor 634SS2 is not available anymore, and I have no clue about what replacement part I can use.


DIY Magnetometer design by GJ4ICD (source)
http://www.uksmg.org/content/magnet.htm
http://www.britastro.org/aurora/jamjar.htm
http://blog.stevemarple.co.uk/search/label/Magnetometer
https://fear-of-lightning.wonderhowto.com/how-to/measure-geomagnetic-storms-with-diy-magnetometer-0132960/
http://www.eaas.co.uk/cms/index.php%3Foption%3Dcom_content%26view%3Darticle%26id%3D74:how-to-make-a-very-sensitive-jam-jar-magnetometer-by-robert-cobain%26catid%3D10:equipment-reviews%26Itemid%3D16
http://www.swpc.noaa.gov/sites/default/files/images/u33/Activity_7.pdf
http://gw7eri.com/homebrew/magnetometer/magtalk.pdf

Building an 80m loaded dipole
In my small garden I can only fit a wire antenna of about 10 to 12 metres in length max. A full size dipole for 80m will be about 40 m in length. With a loading coil in each element the length can be reduced. I'm not expecting much of a 12 metre long loaded 80m dipole, but I still want to see what it can do with my 200 mW U3S WSPR transmitter, and maybe even try to make my first ever 80m 2-way contact, in CW, SSB, or some digi mode. Again, I'm not expecting super DX from it though. If working ok, I'll also want to try making one for 160m. Making coils with the right inductance value is the challenge in this project. I don't have an LC meter. I've been looking at those cheap ones available at the various Chinese selling sites, but the reviews for these are varying from the device being inaccurate garbage to ok for the price.

https://www.nonstopsystems.com/radio/frank_radio_antenna_80m-dipole.htm

November 13, 2017

The Aurora Beacon

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The "Aurora Beacon" transmits on 3.579 and 10.144 MHz with the callsign DK0WCY and on 5.195 MHz with the callsign DRA5. The beacon is located at the QTH of Emil Johannsen DK4LI in northern Germany in grid locator JO44vq. In its CW identifier loop beside its callsign the beacon continuously also sends a data group of four elements consisting of numbers and letters containing the current K index and MUF and indicating if there are unusual propagation conditions in progress or forecasted, like for instance Radio Aurora. At specific times every hour there are also more detailed broadcasts with geophysical and solar-terrestrial data, warnings, and forecasts, in CW, PSK31, and RTTY.

A schedule and information on the format of the broadcasts can be found on the beacon's website. On the website you can also read the history of this fascinating beacon, and how in pre-internet times it was set up mainly to alert the radio amateur community of Aurora conditions being in progress, the only other way of being alerted at the time being part of a telephone network of interested radio amateurs.

The Aurora Beacon somewhere around 2003 with Emil DK4LI.

Blank DRA5 QSL card as found on www.utilityradio.com.
The Aurora Beacon is a project of the DARC Ortsverband Süderbrarup M15 and the beacon manager is Ulrich Mueller DK4VW. I haven't been able to find out who founded the Aurora Beacon, and in what year, but looking at the photo above of around 2003 with the "20 Jahre DK0WCY" sign, I guess it must have been at least somewhere in the early 1980s.

Below you can listen to a recording I made of the DRA5 beacon on 5.195 MHz today with a CW datagram. The complete datagram reads as follows:

VVV DE DRA5 2/13/N/N
VVV DE DRA5 2/13/N/N

INFO
CONDS 13 NOV 1534 UT =
MAG   KIEL K  2 2   KCUR  2.3 2.3 =
IONO   RUEGEN FOF2  4.2 4.2   MUF  13 13   MAXHOP  2263 2263   MUF 1K  7 7 =
SUN   WIND  374 374   DENSITY  5 5   BZ  0 0   XRAY  A7 A7   FLARE  NONE
= =
FORECAST 13 NOV =
SUN   QUIET   MAG  QUIET
= =
INDEX 12 NOV =
R  0 0   SSNE  NA NA   FLUX  69 69   BOULDER A  6 6   KIEL A  9 9
AR

VVV DE DRA5 2/12/N/N
VVV DE DRA5 2/12/N/N

If the third element in the CW identifier data group is an A instead of an N, Auroral propagation conditions are in progress. Below, beside links related to the Aurora Beacon, also some links to webpages about Radio Aurora. During Auroral conditions I've heard the eerie sounding CW and SSB signals on 2m, but I haven't managed to make a QSO yet, and it's still on my amateur radio bucket list. Keeping an eye on the DX cluster and regularly monitoring the Aurora Beacon will hopefully alert me in time to the next Aurora opening to have another try.





See also:

http://dk0wcy.de/
https://www.hfunderground.com/wiki/Radio_propagation_beacon
http://www.kg0vl.com/?page_id=5
http://rsgb.org/main/technical/propagation/auroal-propagation/
http://www.vhfdx.de/aurora.html
http://www.df5ai.net/Material/articles2.html#ArticlesAurora

November 05, 2017

QSL card in the Spotlight: VO1/OZ1AA Thomas Andersen, Cycling the Globe

Last edited: 10.11.2017

In 2010, Dane Thomas Andersen left Copenhagen by bicycle for an epic journey, a cycle touring expedition around the world known as "Cycling the Globe". 6 years later Andersen was back in Denmark, he'd completed his adventurous journey around the world, and in 2200 days had covered a total of 58,201 km through 58 countries!

Thomas Andersen cycling in the Andes on the border of Argentina and Chile. In the background the Lanin vulcano (Photo from the Cycling the Globe Facebook page).
Thomas Andersen also happens to be an avid ham radio operator, holding callsign OZ1AA, and during the trip has been active on the ham bands from the shacks of fellow radio amateurs around the world, old friends as well as newly met along the way.

On  September 20th, 2015, Thomas had just (on September 18th, if I'm not mistaken) reached the easternmost point of North America at Cape Spear, Newfoundland, had been on the road for more than 1800 days, had covered 43,712 km, and was staying with fellow radio amateur Gus VO1MP at his home in St.John's, Newfoundland. St. John's is the easternmost city of North America and well known to radio aficionados for Signal Hill where in 1901 Guglielmo Marconi received the first transatlantic radio signal (the Morse Code transmission originating from his Poldhu Wireless Station in Cornwall, UK). And I was lucky that day to catch Thomas on the air operating from Gus VO1MP's QTH and to QSO him on 20m CW. It was one of my most memorable QSOs and it resulted in the wonderful QSL card shown in this blog post. The VO1 prefix was added ofcourse to denote the QTH in Newfoundland, Canada.

Thomas Andersen (middle) at Cape Spear. Gus VO1MP on the right (Photo from the Cycling the Globe Facebook page).
Cape Spear literally was the end of the road for Thomas on this part of the trip. Next destination would be Africa.

More information can be found on Thomas' qrz.com page, or on www.cyclingtheglobe.com, as well as Twitter and Facebook.



I learned that there's also an amateur radio station located inside Cabot Tower on Signal Hill with the callsign VO1AA, and I wonder if it could have also been this location where Thomas has been active from on 20m CW when I QSOed him (1).

Newfoundland is IOTA NA-027.

You can listen to a recording of my QSO with Thomas below.



Addendum 10.11.2017
(1) Thomas informed me by e-mail that the contact was indeed made from the QTH of Gus VO1MP, not from Cabot Tower.


See also:

http://www.cyclingtheglobe.com
https://twitter.com/CyclingTheGlobe
https://www.facebook.com/CyclingTheGlobe/
https://en.wikipedia.org/wiki/St._John%27s,_Newfoundland_and_Labrador
https://en.wikipedia.org/wiki/Signal_Hill,_St._John%27s
https://en.wikipedia.org/wiki/Cabot_Tower_(St._John%27s)