AmateurRadio.com

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!

“Whoa, pardner! That’s a big jump from what you’re using now! You’ve only been at this for about a year and a half”, the older Ham reminded him.  Sometimes George tended to think that Ham Radio was still the way it was back in his Novice days.  Then, some if not most, Hams had to work a long time to build up their code speed  and  it generally took longer for them to work their way up the ranks. He sometimes forgot that his two prize students were already General Class license holders, having upgraded from Technician Class.

“I know Mr. Mason, but most of that time was spent with you, so I’ve learned from the best. You’ve shown me how to build a kit the right way and you’ve helped me get my code speed up. I’ve almost got all 50 States under my belt and over 40 countries in my log …. and I’m good for about 18 words per minute in the code!” Davey was proud of his accomplishments, and he hoped Mr. Mason was too.

Little did Davey know just how proud George Mason was of the two boys.  Under N2EBA’s tutelage, the two younger Hams didn’t get stuck in the VHF/UHF rut that many newcomers find themselves in.  George got them interested in HF radio operating from “Day One”, and to his delight they took to his favorite mode, CW, like fish take to water.  The way they had increased their code speed so greatly in such a short amount of time constantly amazed him.  His personal theory now was that since Morse Code was no longer an examination requirement, people who really did desire to learn the code, took to it more quickly.

Confirming his respect for Dave and Jimmy’s achievements, George stated, “You and Jimmy were top notch students, Davey. I am proud of both of you, and how far you’ve both come since you started. Amateur Radio is a lifelong hobby that can serve you well. How has Jimmy been doing?”

“OK, I guess”, Davey started to explain, “But he doesn’t get as much on-the-air time as I do. I have the kits that you and Mrs. Mason gave me, and that you helped me build. Jimmy doesn’t have a shack at home … his parents can’t afford it right now. So I have him come over and use mine anytime he wants.  At home, he keeps an ear on the Ham bands with an old Hammarlund receiver that his uncle found for him, but it‘s not the same as having your own station set up, and actually making QSOs“, Davey responded.

“Well, you’re a good friend, David Bolton. Other people aren’t so generous. Helping other Hams and passing on Ham Radio traditions are part of what this hobby is all about.  Amateur Radio helped to teach me the electronics skills that I needed and used during my 40 plus year career. I like to think that now I’m doing my part to keep the hobby alive. It looks like you’re setting out on the right foot in that regard, too.” George Mason was indeed very proud of his young students.

And right then and there, the seed of an idea took root in Davey’s brain.  He didn’t know exactly how he was going to accomplish it, but he knew he still had a little time before Christmas came.

The time before Christmas seemed to be speeding by in the blink of an eye.  There was school, chores to be done around the house, and of course radio time whenever he could squeeze it in.  And there was Christmas shopping to be done!  Davey used what money he had to buy Christmas presents for his Dad, the Masons and Jimmy.  Jimmy’s present was going to be a special one this year – he just had to figure out how to go about getting it.

One evening after school, while Davey and George were in George’s shack, trying to get into the log of an fellow Amateur that was on a DXpedition to a far away island in the South Pacific, the doorbell rang, and Davey’s father showed up to bring him home.

“Thanks so much, Jeannie, thanks so much George”, Jason Bolton offered to the Masons.  “Davey’s not being any trouble, is he?”

“You’re kidding us, right?”, the Masons both asked with one voice.  Jeannie said, “Jason, Davey’s as good as gold and no trouble at all. He’s a fine testament to the job that you and Abby have done bringing him up”.  George added, “Davey’s my star pupil Jason, he can spend time in my shack any day”.

“Hi Dad!”, Davey greeted his father as he bounded up from the basement.

“Ready to go, Sport?” Jason asked his son.

“Any time that you are, Dad” Davey told him.

As the two walked home, Davey asked his father if there was going to be much more overtime. “I realize the medical bills were high Dad, but I miss spending evenings with you.  Think this will be over soon?”

“Well Davey, I am seeing a light at the end of a tunnel, and I don’t think it’s a train”, he joked with his son. “I think that the last week before Christmas will be the last week that I’ll have to work late. Then things can go back to normal.  Hey, I’ve been so busy that I forgot to ask you what you wanted for Christmas this year – anything special?”

Davey wanted to just burst open about the QRP rig that he wanted so badly. But he knew the price and he knew his Dad’s financial situation. So instead, he said,”Not really, there’s some books and a video game or two I would like”.

“Hmmmmm …… no radio gear?”, his Dad asked.  “I know there always some kind of key or accessory that you have your eye on – nothing like that? There‘s still time for me to order something, just point it out to me, as I don‘t know a transmitter from just about anything else you use!”

“No Dad – not this year.”

“Have you gotten all your Christmas shopping done; or do you need me to drive you over to the mall again?”

“I’m just about all done Dad, but I need a huge favor”, Jimmy asked.

“And that would be …….?” his Dad asked.

“I need you to write out a check for me.” Davey’s entire plan seemed to tumble out of his mouth in mere seconds. “I want to buy Jimmy a rig of his own for Christmas. Just a small kit, nothing too big – I know his parents can’t afford it and I know that Jimmy really misses not being able to get on the air as much as he wants.  There’s a place where I can order one, that will get it here in time for Christmas, but I don’t have a credit card or a checking account, so if I give you the cash, do you think you could place the order for me?”

His father was quiet for a few seconds, and then asked, “Davey, are you sure you want to do this?  I know you’ve been saving up for something that you’ve been wanting very badly.  Isn’t this going to deplete your savings?”

Davey replied, “That doesn’t matter, Dad.  Jimmy’s the closest thing I have to a brother and he loves Ham Radio as much as I do. It kills me that he can’t spend as much time on the air as I do”.

Jason Bolton sighed, ”OK then; but only if you’re sure. But then again, you did inherit your generous streak from your mother.  So …..  you’re really set on doing this?”

“Sure am, Dad!”, Davey answered. And that night, they ordered the kit that Davey had in mind, on line.  They got the total and Jason Bolton  put the order on his credit card.  As Davey was handing him the money, he said, ”Wait a sec, Davey. How about we split this? As much as I admire your generosity, I hate to see you eat up all the rest of your savings”.

“Thanks, Dad, I appreciate the offer; but this is something I’d like to do on my own”.

“All right, we’ll do it your way this time. Your Mom sure would be proud of you, and so am I”, his dad told him, and giving him a big hug, said ”You’ll never be too old to get one of these from your Old Man.”

To Be Continued …..

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

Blogger tells me that this blog contains 999 posts, which must make this one the one-thousandth. When I started blogging almost four years ago back in February 2009 I had no idea that it would go on for so long.

Of course, the events of 18 months ago gave me every reason to believe I would never achieve such a total. Fortunately fate, having given me a metaphorical kick in the crotch, decided to smile on me after all and so I have defied the doctors’ predictions. Slowly but surely I have been going from strength to strength, so that I think I have a fighting chance of going on for at least another 1,000.

I would like to take this opportunity to thank all of my readers, especially those who comment or email, without whom the whole business of blogging would be a waste of time. I am particularly grateful to the many who sent messages of encouragement which were a great morale booster to both Olga and myself during a difficult time.

I hope you will all keep reading this as well as my “brain tumour blog” One Foot in the Grave, which is rapidly approaching a milestone of its own. I hope I will keep on “beating the bastard” and carry on blogging (and hamming) for years to come.

No sooner had the question entered Davey’s mind, than he heard some noise come from the backyard.  As the boy walked up the driveway to investigate the source, he saw George Mason fumbling with some tools.

“Hi, Mr. Mason, what are you doing?”

George looked up to see Davey’s smiling face.  “Why Davey!  You’re a sight for sore eyes!  I’m trying to measure out some wire for a new antenna. It’s hard to manage tape measure, wire and wire cutters all at the same time.  I could use another four hands, or maybe an octopus. Want to lend an Old Ham some help before you go in your house?”

“Oh yeah, sure. About that …………” Davey answered.

“What’s the matter Davey?  Something happen?” George asked his young Ham friend.  He could tell from the way the expression on Davey’s face fell that something wasn’t quite right.

“Well, Mr. Mason, it’s like this.  I was helping Jimmy with his books on the way home from school.  He can’t manage them well and deal with his crutches at the same time.  Anyway, he dropped one as we were crossing the street. When I bent down to pick it up for him, the house key popped out of my jacket pocket and went down the storm drain.  Dad’s going to have a fit!” the boy explained.

“Oh, Davey!  No worries! Your Dad’s not going to have a fit.  I’ll tell you what, you help me measure out and cut this wire and then I’ll go inside and phone your Dad to tell him what happened, and let him know that you’re at our house.  Your Dad is a good man and I’m sure he’ll understand that it was just an accident. And you can stay with us, of course, until your father gets home.  By the way, Mrs. Mason just baked a fresh apple pie today; and I’ll bet you it’s just about cooled down enough for a slice”.

“That’d be great, Mr. Mason. Thanks for your help!  So ……. Exactly what kind of antenna are you putting together, anyway?”  Dave had a keen interest in antennas and how they worked.

“Well, Davey ….. It’s something that I found in the ARRL’s Antenna Book.  It’s called a W3EDP antenna and it was first used way back in the 1930’s.  It’s based on the wire antennas  that used to trail from zeppelins.  I need something that will get me onto 80 and 40 Meters. My vertical is good on 20 Meters and up, but it sure doesn’t do anything for me on the lower frequencies, and now that Winter is just about here, I’d like to get on those bands at night.”

Dave helped his neighbor measure out the wire and handed Mr. Mason the wire cutters when they were needed.  When they were finished, the two Hams went inside.

“Davey, why don’t you sit down and take a load off? I’ll call your father like I promised. And don’t worry, I seriously doubt that he is going to have a cow!”

Dave settled down at the kitchen table and engaged in some small talk with Mrs. Mason while George telephoned Jason Bolton, Dave’s father. Jeannie Mason doted over Davey and she loved him as if he were her own. She was always like a grandmother to him, but after his mother died, she became even more devoted to him.

After a few minutes, George came back in the kitchen. “Good news, kiddo!  Your Dad understood completely.. He even said that it was good thing that you were here. He was actually going to have me come over to your house and have me bring you over here. Looks like he has to put in some overtime again, and he wanted you here with us. So it looks like that slice of pie I promised will end up being dessert, as you’ll be eating dinner here. Do you have any homework?”

“Yes, Mr. Mason, I have some Science reading and a Math worksheet to do.”, Davey responded.

“Better get cracking then. I think Mrs. Mason is planning to have supper ready in about an hour. Isn’t that right, Dear?”, he asked.

She nodded affirmatively, so Davey started in on his homework. George told Davey that after dinner they would go down to George’s shack and cobble together the antenna that they had cut the wire for.

A couple hours later, after school work was finished and dinner was eaten, the two radio operators found themselves in N2EBA’s basement shack. Davey loved being in “a real Ham shack”, as he thought of it. There were quite a few pieces of Heathkit gear that George had built and had lovingly maintained over the years. The jewels of the shack that Davey had envied the most were George’s Elecraft rigs. A KX1, a K1, a K2 and a K3 were all on the main operating bench. George was a die-hard kit builder, QRPer and a CW man. The only thing missing was the new portable rig, the KX3. George was putting money on the side for one, and when it arrived, George had promised Davey that he could be involved in the build. That suited Davey just fine, as he had dreams of owning his own copy of the radio which had caused a huge buzz among members of the QRP community.

Tonight, however, they concentrated on building the new antenna. They talked as George watched while Davey soldered wire to some window line.

“Sorry that you have to be here instead of home, Davey”, Mr. Morgan offered.

“I don’t mind in the least, Mr. Morgan. I just wish my Dad didn’t have to work so much. But the overtime is helping him pay off what’s left of Mom’s medical bills. It’s been real hard on him since she died.”

“I know it’s been tough for him, Davey. You’ve been a big consolation to him. He’s told me several times that he doesn’t know what he’d have done without you. But enough of that talk, Christmas is coming real soon. If you don’t mind me asking …. are you and your Dad putting up a tree this year? I mean with your Mom passing on earlier this year and all…”

Davey nodded his head, “Yeah we are, Mr. Mason. Dad told me that Mom made him promise that we would. She’d be mad if we didn’t celebrate Christmas on her account. It was her favorite holiday.”

“Well then, have you given any thought to what you’d like to find under your tree?”, George asked, his eyes twinkling.

“Heck, yeah!” Davey blurted out, “I’d sure like to see a KX3 under there! But I don‘t even dare think about that.  With all those medical bills, there‘s no way I would even mention that that‘s what I really, really want.  So in the meantime, I’ve been saving what I can from my allowance, birthday money I’ve received and grass cutting money that I’ve earned. I’d like to be able to buy one on my own, but it feels like it’s going to take forever to save up that much money!”

To Be Continued……

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