Arduino Sidecar (instead of a Shield)

In my last post I described my Arduino Keyer Kludge.  In that project I didn't use the standard "shield" board that normally sits atop the Arduino board.  I had used a shield in an earlier project and I didn't really like it.   I prefer to have all the electronics and connections on the top of the board -- this makes for easier experimentation and modification.  

Above you can see my "sidecar" technique.  I build the circuit on a piece of copper clad board using isolation pads superglued to the copper (aka "Manhattan style").   For the Arduino board, I just superglue a piece of balsa wood to the copper clad board, and attach the Arduino board to the balsa with small wood screws.  Electrical connections from the Arduino to the sidecar just go from the Arduino pins to the appropriate points in the sidecar circuit via small-gauge wire.  

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Paddle Output Arduino Keyer Kludge (video)

Ooops -- I got my keyer terminology wrong in this video.   The K1EL keyer just needs a "paddle keyer" input, not an iambic keyer.   One line is brought to ground for dots, another for dashes. (With an iambic keyer, if you make both contacts at the same time you get a string of alternating dots and dashes.)  My homebrew cootie keyer did the job, but I wasn't very proficient, hence the need for this digital kludge. I also got the name of the Arduino guru wrong: he is Massimo Banzi.  Mi dispiace Massimo.   


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

SolderSmoke Podcast #153 -- SPECIAL FDIM PODCAST

SolderSmoke Podcast #153 is available for download:

http://soldersmoke.com/soldersmoke153.mp3

June 22, 2013 

Manassas Hamfest
Building a Balanced Modulator in LTSpice
Peter Parker's Minimalist SDR receiver
Alberto I2PHD's SDRadio program
My Arduous Arduino Adventure:  Sig Generator
MAR-1 amplifier chip
WSPRing again (the sound of WSPR)
Broadening my Barebones Superhet for phone
Cliff Stoll on Kludge vs. Kluge
FDIM INTERVIEWS:
G3RJV on one and done projects, Sodder vs. SoLder, Regens
G3VTT plays SolderSmoke for his students
NM0S on new Four States PTO rig
K0NEB on kit building techniques
NH6Z on high performance SDR
KK7B on hard rock rigs, modular construction and understanding
I2RTF Saluti a tutti!
W7EL on EZNEC, Dilbert, and escaping the Cube Farm
W1REX on QRP as a creative outlet,  Knack to the Max!

 

SPECIAL THANKS TO SOLDERSMOKE'S DAYTON CORRESPONDENT:

BOB CRANE, W8SX

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

A Billion Pixels From Mars

Don't miss the hi-res version.  Link and background info here:
http://www.jpl.nasa.gov/news/news.php?release=2013-205&cid=release_2013-205


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Feynman's Red Book (on the Sino-Indian Frontier)

Today I bought a copy of "Feynman's Tips on Physics."   I wasn't sure about buying it, but this story in Ralph Leighton's foreword convinced me:  

"At a lonely border post high on the Himalayan frontier, Ramaswamy Balasubramanian peered through his binoculars at the People's Liberation Army soldiers stationed in Tibet ― who were peering through their scopes back at him. Tensions between India and China had been high for several years since 1962, when the two countries traded shots across their disputed border. The PLA soldiers, knowing they were being watched, taunted Balasubramanian and his fellow Indian soldiers by shaking, defiantly, high in the air their pocket-sized, bright-red copies of Quotations from Chairman Mao ― better known in the West as "Mao's Little Red Book."

Balasubramanian, then a conscript studying physics in his spare time, soon grew tired of these taunts. So one day, he came to his observation post prepared with a suitable rejoinder. As soon as the PLA soldiers started waving Mao's Little Red Book in the air again, he and two fellow Indian soldiers picked up and held aloft the three, big, bright-red volumes of The Feynman Lectures on Physics.

One day I received a letter from Mr. Balasubramanian.  His was among the hundreds I have received through the years describing the lasting impact Richard Feynman has had on people's lives.  After describing the "red-books" incident on the Sino-Indian Frontier, he wrote, 'Now, twenty years later, whose red books are still being read?' "   

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

The Jamesburg Dish

Mama mia!  That's an antenna!  This is the skyhook that the very hip people in yesterday's video (scroll down) are using to send very cool messages to Gliese 526.  With a setup like that, they may have a shot at a QSO!  

More on the antenna here: http://www.jamesburgdish.org/

As I suspected, real hams (not the hipsters!) are doing the tech work. 
 
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

LONE SIGNAL: SETI gets cool. Perhaps TOO cool! (VIDEO)

Slashdot alerted me to this new SETI-like effort to communicate with extraterrestrial civilizations.  It is called LONE SIGNAL.  Check out their video (above and here:
http://youtu.be/M-XcrnSKUog )

http://news.discovery.com/space/alien-life-exoplanets/crowd-funded-radio-beacon-will-message-aliens-130612.htm

The project has many features that put it in the traditional SolderSmoke area of interest, especially  "the use of a re-furbished radio telescope."   But one look at their video (click above) made me think that perhaps these folks are just too cool for a project like this.  I somehow can't see ANY of these people using a soldering iron.  On the other hand, if WE had videos like this, maybe we'd be able to bring more young people into ham radio!  Yea!  Why can't we be cool too? How about it, ARRL?


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

The Manassas Hamfest

Elisa heroically accompanied me to the Manassas Hamfest on Sunday.  We had fun.  I thought they had a good turnout of vendors and tailgaters, and it seemed like the sellers of real ham stuff were winning the battle against the encroaching computer people.  I saw many interesting old boatanchor radios, including two R-390A receivers, one HT-37, an HW-101 and several other Heathkits.

As for NEW technology, the fellows from the NOVA LABS maker space had a very interesting table, and their web site has a very kind acknowledgement that hams were "the original hackers, who organized build groups and hack labs similar to modern day makerspaces—back before people called themselves “Makers” and long before it was “cool.”  They had a 3-D printer that was doing its thing in a very impressive manner.  They also had some quadro- and octo-copters built by a group called DC Area Drone User Group.   Very cool.  Want one.

Inspired by Nick Kennedy, I have included in this post a picture of my purchases from the hamfest.  As you can see, I controlled myself.  But I couldn't resist the humungous flashlight!  I got a bunch of .1 caps (should have bought more!).  Got a Bud-box (maybe for an Arduino DDS project?)  The little circuit board with the IF cans is interesting.  I bought it (1 dollar!) for the 365 pf variable  cap, but I later realized that it is probably a complete All-American Five receiver on a single board.  I'm not crazy about tubes on PC boards, but this one may have some possibilities.  The roll of tape is supposedly coax sealer.  I also got a little 35 mm slide viewer, and a 12 volt wall wart.

I wore the "Real Radios Glow in the Dark" T-shirt that Elisa got me (on the recommendation of Rogier).  I got more positive comments on that shirt than on any other piece of clothing I've ever owned!

And we saw our first Cicadas of this 17 year cycle. 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

OOPS! Why the AD9850 DDS Boards are So Inexpensive

N3ZI has a very plausible explanation for the low price (about 9 bucks!):

My guess is that this is a liquidation due to a design build error, since they are being sold for a price of about 1/2 the price of the DDS chip alone. The modules are assembled and tested. The design error I noticed is that the wrong output filter is used. These boards use the 9850 running at 125MHz. A 125MHz DDS should have a 50MHz LPF, but it seems that these modules have the 75MHz LPF the chip maker recommends for the AD9851 running at 180MHz. My guess is, someone just copied the wrong filter from the wrong data sheet, and it wasn't caught until they went into production.
But for amateur radio applications they work fine up to about 40MHz. You can push them to 50MHz by adding a correcting filter, which is included in my controller PCB, but the output level is low in the 40-50MHz range.

N3ZI continues to offer some really interesting microcontroller products.  He has a controller board that allows you to simultaneously control TWO AD9850 boards.  This might be exactly what we need when we have a separate receiver and transmitter with different intermediate frequencies: Set up one board with the VFO freq for the receiver and the other for the transmitter with the resulting operating freq displayed on the LCD.  Viola! No more "Spot" or "net" and zero-beat by ear! (But I may be one of the last people on the planet still doing this!)   

N3ZI's site:  http://www.pongrance.com/

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

R-390A and Homebrew TX put in Transceive Mode (VIDEO)

N8ZRY has a very nice video on his recent adventures with the legendary R-390A receiver (want one!) and his homebrew 20 meter SSB transmitter.  He manages to essentially put the receiver and transmitter into "transceiver" mode.  Very nice.  I wonder if he had previously used the old standard "spot" or "net" "zero beat by ear" method?  This video has me thinking about ways to bring my many separate receivers and transmitters closer together. The problem is that they all use different IF frequencies (the crystal filters are at different frequencies).  But using my Arduino-based DDS VFO, I guess it wouldn't be too difficult to program the thing to generate one VFO freq for transmit, and a different VFO freq on receive, in effect putting the transmitter and receiver on the same frequency. 

Both the R-390A and the homebrew transmitter look great.   Thanks Greg!


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20