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Looking at my IBP beacon monitor pages over the last couple of days I have noticed an odd thing. I am not receiving the Madeira beacon CS3B on 17m at all.

Extract from G4ILO beacon observations

Either my multiband dipole has a very sharp null in that direction (which I think is unlikely as an indoor antenna probably receives enough reflections not to have any sharp nulls) or the beacon isn’t transmitting any signal on that frequency.

A quick check around other beacon monitor pages and I can’t see any spots of CS3B on 17m at all. Should I tell someone?

Series Five Episode Twenty-Six of the ICQ Amateur / Ham Radio Podcast has been released. The latest news, listener mailbag and Martin reviews the Raspberry Pi for Amateur Radio

• Issues with Northern Ireland Amateur Radio Exams
• ACMA warning about non-compliant goods
• VK5VF Adelaide beacons back on air
• Taiwan Radio Hams seek additional allocations
• FreeDV Ham Radio digital voice software
• GB2BP QRT
• Ofcom announces additional 5 MHz channels
• Update from Campbell Island DX

Series Five Episode Twenty-Six of the ICQ Podcast has been released. News Stories include :-

• Issues with Northern Ireland Amateur Radio Exams
• ACMA warning about non-compliant goods
• VK5VF Adelaide beacons back on air
• Taiwan Radio Hams seek additional allocations
• FreeDV Ham Radio digital voice software
• GB2BP QRT
• Ofcom announces additional 5 MHz channels
• Update from Campbell Island DX

Listener mailbag and Martin reviews the Raspberry Pi for Amateur Radio

I had some time this morning to experiment with the RTLSDR USB dongle which I’ve previously mentioned. Designed as a DVB TV/DAB receiver, with different drivers, they can be used as a wide band scanning receiver. As I mentioned yesterday, I’d seen Pete 2E0SQL report success in decoding the ADSB transmissions from aircraft with his stick.

I used my latest USB dongle with the E820T tuner – having made sure that the drivers were up to date. The first ADSB decoder that I tried was the ADSBSharp program which you can download from here Having installed that – I started the program with the dongle plugged into a USB port and a small antenna which came with DVB stick plugged in. Immediately I could see that the dongle was decoding frames – and quite a few of them.

I wanted to try and plot them, so I started up ADSBScope which you can download here

From the menus, I selected Other/Network/Network setting and set the Raw Data CLIENT (not the server) to port 47806 which ADSBSharp was ‘broadcasting’ on. The URL should be set to 127.0.0.1

I then pressed the RAW Data Client icon – it’s the right hand of the group of three ‘network’ icons on the icon bar. Lots of messages started appearing in the right hand pane, but very few position decodes. I filtered around with the filter but didn’t see much improvement.

Honour was sort of satisfied as I knew the data was being decoded, but I wondered if if I could do better. I’d seen some discussion on Twitter about the RTL1090 software which would work with the RTLSDR dongle and should decode the data. I downloaded the program and installed it from the RTL1090 website

Running the program up, I could immediately it seeing aircraft and displaying ‘Active Flight’ data. However, even after reconfiguring ADSBScope’s Raw Data Client to point at RTL1090 which was running on port 31001 ADSBScope was not displaying flight information.

I then remembered seeing in the ADSBSharp instructions that you had to configure the client to use AVR format. I had no idea what that was, but wondered if I should get RTL1090 to send the data to ADSBScope in AVR format. This was what cracked it! Simply start RTL1090 from a command prompt with the /AVR flag and the data will then be sent to ADSBScope and mapped.

I am surprised how sensitive the receiver is. Not as good as the LZ2RR  ADSB dongle, but as you can see from the map, the system is quite capable of receiving aircraft over distances of 20 to 50 miles away – even with a basic indoor antenna.

Definitely a great use for the DVB dongle, especially if you have been interested in Virtual Radar, but were put off by the prices!

Christmas Eve came and Dave and his dad attended Midnight Mass together. Jason sat in one of the pews while Davey pulled duty as an Altar Server.  The next morning, they opened up their gifts to each other. Jason was very pleased with the gloves and hat and scarf that he received from Davey. Likewise, Davey loved the books and video games that his Dad had given him. He knew that money was tight this year, and he appreciated all his dad had given him.

While cleaning up the breakfast dishes together, his dad reminded him that they would be having dinner over at the Mason’s later in the afternoon. “You know that the Masons invited Jimmy and the Stapletons over for dinner too, right?”, His father asked.

“Yes, sir”, Davey answered, “It was nice of them to do that.  I have Jimmy’s kit all wrapped up and under their tree, so that when Jimmy gets there, he can open it.  He has no idea ……. this is going to be great!”

Then his mood changed and he got quiet, and after a few moments, his dad said, “I know Davey, I miss her too. Your Mom and you are the most important things in my life. I love you both so much – you’ll never know how much.  Just know that she’s looking down on us and is glad that we’re celebrating her favorite holiday together.”

Dinner at the Mason’s was a feast.  Mrs. Mason, who was by any measure a great cook, outdid herself.  There was a turkey, there was a ham, there were mashed potatoes, gravy, yams, cranberry sauce, vegetables and home made buttermilk biscuits.  For dessert there were three kinds of pie.  Nobody could outcook Mrs. Mason. Everyone enjoyed the meal and the friendship.  After they had all stuffed themselves to the gills, Mrs. Mason called everyone over to the tree.  “Santa was here last night and left some presents!” she gleefully informed her guests.

There were presents for the Stapletons, who were overwhelmed and didn’t know what to say.

“Don’t say anything”, George said.  “Jeannie and I know what you’re going through, we’ve gone through it a few times ourselves over the years; and with God’s help, we always got by.  Some day, when things are better, you do the same for someone else.”

Then Davey handed  Jimmy a gift wrapped box.  Jimmy took it eagerly, “Oh man, I wonder what this could be?”

“Well open it up, knucklehead!” Davey kidded his friend, “Unless you’re like Superman and have X-ray vision, you’re never going to know until you do.”

Jimmy unwrapped the gift and saw that it was a kit for a QRP Tri-band transceiver, a popular model by famed QRP designer Steve Weber KD1JV. “Davey, are you nuts? This must have set you back a ton!”

“Hey buddy-boy, don’t yell at me, yell at Santa, he’s the one who brought it here”, Davey glibly replied.

“Yeah, well, “Santa” is the greatest friend a guy can have – tell him I said so the next time you see him”. Jimmy looked at his friend with a stunned look of disbelief still on his face.  Mrs. Stapleton had a few tears welling up in her eyes, overwhelmed by the generosity of their friends.

Davey told his friend, “Santa wasn’t able to dig up an antenna tuner or a paddle, though. I’m afraid you’re going to have to come up with those on your own”.

That’s when Mr. Mason chimed in ”I’m sure that there’s enough stuff in the N2EBA parts box, that we can come up with a QRP antenna tuner. And if I’m not mistaken, Jimmy, I think Santa left you another box under the tree”.

This time, George handed a small box to Jimmy.  When Davey told George what he was up to, their Amateur Radio mentor decided to buy Jimmy a Bencher paddle to go with the rig.

Jimmy looked at them, “The both of you are the best. Thanks so much!  This has been a great Christmas!”

Then Mrs. Mason came over to Davey and whispered something in his ear.  With a quizzical look on his face, he moved over to the Christmas tree when he heard her say, “Go on, Santa left one for you, too.”

Davey found the box with his name on it.  Caught totally off guard, he sat down on the floor next to it and began to remove the brightly colored wrapping paper.  He caught his breath for a second when he saw what it was – the Elecraft KX3 kit that he had wanted so badly!  He immediately looked at his dad, who simply nodded and said, “There’s a note attached to the box, Davey.  I think you might want to read it”.

He opened the envelope – inside was a plain sheet of paper with handwriting on it – his mother’s handwriting.  She had written the note shortly before she died.

“Dear Davey,

With all that has been going on, your Dad and I decided that we wanted to buy you a very special Christmas present this year.  We both know that this is something that you’ve really wanted and that you were trying to save up for on your own.  We also know that you’ll get a lot of enjoyment from this for years to come.  So no matter what happens, or wherever life takes you, please know in your heart how much your Dad and I love you.

My love always and Merry Christmas!

Mom”

This time, Davey was the one caught speechless. With tears glistening in both their eyes, he looked at his Dad, and his Dad looked back at him.  Both had smiles on their faces. As much as he had wanted the radio, that small piece of note paper with his Mom’s handwriting  that he had just received, and what it represented, meant more to him than anything in the world. Dave Bolton still missed his Mom terribly, but now he knew that she would always be with him.

“You’re right Jimmy”, he said, “This IS a great Christmas”.

Note: The names and call signs that appear in this story are purely fictitious with two exceptions. Steve Weber KD1JV continues to design kits that are sold primarily through Hendricks QRP Kits. N2EBA was originally issued to Mark Rosenwald, a good friend of mine who is now a Silent Key.  Thanks Mark, and a Happy Hannakuh to you, in the Big Shack in the Sky!

72 de Larry W2LJ
QRP – When you care to send the very least!

I had an email from a KComm user from Russia today. He reported that when he clicks on a spot in the DX Cluster window the message “Invalid floating point operation” appears.

I guessed immediately what the cause of this was. It’s a problem that has been the bane of my life ever since I started programming as a hobby. In most of Europe the character used for the decimal point is a comma, not a dot (or period as our American friends say.) If your program is being used in a European country, adopts the correct regional settings and then reads some data expressed in the US or British way (such as the frequency in a DX Cluster spot) when it tries converting data to a binary floating point value it will come up with an error. If the European Union was actually any use you might think they would have standardized the representation of numbers by now, but hey…

If you are affected by this issue then a workaround is to use the Regional Settings in Control Panel to change the decimal separator to a dot instead of a comma. I’ve looked at the KComm source code and fixing the problem doesn’t look as if it is going to be easy so a solution may be a little while in coming.

Chatting to Pete 2E0SQL on Twitter yesterday, I was excited to hear that he had been able to decode ADSB transmissions from aircraft using his RTLSDR dongle (you’ll recall that these are the devices which cost around a tenner). Although this is nothing new in the Linux world, it’s new to me in the Windows world.

Even better news is that it’s very simple to do.

If you already have the correct drivers from ZADIG installed, you should only need to grab the executable which is available on the SDRSHARP site

I haven’t tried this myself yet, but Pete reported that he was able to decode data and plot it, using Virtual Radar Server using just a bit of coax for an antenna!

I will give this a go over the next few days – as it sounds interesting!