AmateurRadio.com

Weather balloons have been routinely launched into the atmosphere for many years by government and commercial organisations for the purpose of scientific and meteorological observations and research. Hundreds are launched daily around the world, using predominately renewable Hydrogen as the lifting gas.

These balloons invariably carrying radiosondes, a battery powered telemetry instrument package to measure various atmospheric parameters and transmit them to a ground receiver. Worldwide they operate on radio frequencies around 400MHz and 1680MHz.

Last year I discovered the hobby of High Altitude Ballooning, where enthusiasts send up their own balloons loaded with experimental payloads and radio telemetry trackers using low power transmitters and amateur radio data modes and frequencies. I have since had a great deal of enjoyment receiving and decoding these as well as developing my own payload.

I decided last year to also try my hand at decoding the commercial radiosondes. Reception of the telemetry signals is relatively straightforward as they are of higher power than the hobbyist transmitters and decoding can be done by the Sondemonitor program from COAA available to individuals to produce graphs and charts of temperature, pressure, humidity as well as the location (if transmitted) and height of balloons.

The software is available for a 21 day trial but when I attempted to install it I was thwarted by a licensing issue caused I believe by installing trial versions of COAA's ShipPlotter and PlaneSpotter programs in the past, despite this I still decided to purchase a software licence for the princely sum of €25.

However this was just before the Christmas upheaval and the dismantling of my receiving set up and so it got mothballed and I have never got around to using it till now.

It was quite by chance that I was flicking around the SDR yesterday using my original (Version1) FUNCube Dongle PRO when I spotted a Radiosonde signal on 404.2MHz, my interest was piqued. (It should be noted the later FUNCube Dongle PRO+ unfortunately has a coverage gap on this frequency so cannot be used)

I connected to my magical HAB antenna and using SDR# and the Sondemonitor program I received and decoded my first radiosonde early this morning and a second flight around noon.


The program produces some interesting graphs showing temperature, humidity, pressure and other measurements during the ascent and after the balloon burst, as well as Tephigrams.


 
I am not sure where these balloons are launched from. The Radiosondes are identified by the software as Vaisala SGP models (but have no GPS data?)  Checking the Vaisala website there are a number of devices and one downloadable document is a comparison of the Vaisala Radiosondes made by the UK Meteorological Office in 2013 (pdf file) which mentions a site in Camborne in Cornwall, but I have also seen mention elsewhere of a site in Larkhill on Salisbury Plain.

The Met Office document also hints that the Radiosonde currently used by them is one of the Vaisala RS92 range, indeed the RS92-D appears to be a device which has no on board GPS and would fit with the GPSless decodes I have made.

Definitely another interesting radio diversion and if you are interested then reception can be made using RTL-SDR receivers as this tutorial on RTL-SDR.com demonstrates, but bear in mind the demonstration/tutorial shows GPS information being received which I have not seen on either of the two launches.


Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

I was finally able to put the finishing touches on the new GW3UEP Class-E transmitter by mounting the hardware on a small 19" panel.

Added to the panel were a 5A DC meter to monitor drain current, a keying jack and a key shorting-switch for keydown testing. This is the third version I have built using the design on Roger's page, with all three performing pretty much as advertised. It is an inexpensive, easily reproducible design.


Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

…..the summer of 2014 that is. Boy it has been hot lately. Last Monday we had a record for September: over 38 degrees Celsius and my own weather station peaked at 39.0 degrees. And the end is still not in sight. Tropical storm Fung-Wong will bring some much needed rain this weekend and with it somewhat lower temperatures. But after that it is back to spending day after day with sweat soaked clothes stuck to your body. With the shack on the top floor and without airco it is now oozing heat, even at night. And I so long for heating up my iron and getting ready for winter DX fun on the lower bands. Patience is a virtue and I need lots of it. 73 and stay cool.

Hans "Fong" van den Boogert, BX2ABT, is a regular contributor to AmateurRadio.com and writes from Taiwan. Contact him at [email protected].

G1KQH has found some very low cost TDA2003 ICs.  I use one of these in my VLF beacon shown in my RSGB RadCom article and on my website. Best range is just short of 6km by “utilities assisted” earth-mode.  When fitter again (currently I am not allowed to drive and I am still too clumsy when on my feet and moving because of my brain bleed last year) I intend to continue my VLF experiments. I have used these ICs at 8.97kHz, twice, and sub-multiples of that frequency.  Beyond 20kHz would be outside their spec limits, but they may still work?

G3XBM 5W VLFearth-mode CW/QRSS beacon

Evening Roger,

Used in your LF PA 10p each nuts!

http://www.banggood.com/100pcs-TDA2003-10W-IC-Car-Radio-Audio-Amplifier-Integrated-Circuit-p-944202.html

Or you can buy in 10s @ 16p each inc delivery!

http://www.banggood.com/10pcs-TDA2003-10W-IC-Car-Radio-Audio-Amplifier-Integrated-Circuit-p-922620.html

Banggood sounds Chinese. I have no idea if these are genuine parts or not. They are advertised as 10W car radio audio parts.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Judy and I rode our bikes along the Pemigewasset River in Old Hill. I stopped on a knoll overlooking the river for 15 minutes and worked Belgium, Moldova, W1AW/4 in NC and Germany.

The day was fine, but a bit cool and breezy. It definitely feels like fall is approaching. Every now and then the scent of wild apples would fill our nostrils as we peddled along. Yellow leaves lay on the path. Wild asters dotted the lane way.

On the knoll I tossed my line over a pine branch and hooked up the KX3. I started out on 17 meters. Right away I worked Pat ON7PQ in Belgium. He was 599 and gave me a 569. Then… another quick contact with
Moldova… ER3MM, Victor. He gave me a 449.

Then I switched to 20 meters and heard W1AW/4 in North Carolina booming in. I made the contact easily.

I switched to 15 meters for one more QSO. Hans DL8MCG was calling CQ and I answered him. I wasn’t strong… barely 539, but we had a nice chat. “UR FB with 5W,” he sent when I told him I was QRP. Hans was running 500 watts to a vertical.

I packed up and joined Judy who was knitting in the sun farther down the lane.

The crickets are singing a new song now. It’s the song of cooler days and the coming of winter.

Jim Cluett, W1PID, is a regular contributor to AmateurRadio.com and writes from New Hampshire, USA. Contact him at [email protected].

W1ZU's home setup.

I had some spare time just before dinner time and thought it would be a nice idea to sit down and relax at the radio. The rig was set to the QRP watering hole of 14.060 and very soon after I heard W1ZU calling CQ. Now having said that I just read the other evening in my CQ magazine of how important it is to listen, so I thought I would give the ears a workout and the key could sit idle. By listening I found out that W1ZU was operating from a summit in Maine, that he was activating SOTA (summits on the air) summit W1/DI 006. Not being an active SOTA chaser I did some more listening and was very surprised how fast the pileup developed to contact him. It would seem you can obtain points for contacting summits and this one was worth one point. Once the pileup settled down I threw my call out and Scott came back to me with a decent report. If I did not spend the time to listen and just tossed my call in and make the contact and move on I would never had learned the detailed info about this contact.
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].