BITX Build Update #3

This weekend I built the VFO.   I used Doug DeMaw's FET Hartley, from his "QRP Notebook," page 50.

Getting a VFO into the desired frequency range always seems to involve a bit of "cut and try."  Not only do you have to get in the correct freq range, but you also have to try to get the tuning range of your variable cap (or coil) to match the band you want to cover.  In my case, thinking of 20 meter SSB, I need about 200 kHz of tuning range.  And sticking with my 9 MHz (for 20) and 13 MHz (for 17) plug-in filter plan, I need the VFO to be in the 5 MHz range. 

That main tuning cap you see above has more capacitance than necessary (19-148 pf).  One option would be to pluck out some of the rotor plates (been there, done that).  But that seems a bit barbaric, so instead I just reduced the overall capacitance by putting a smaller fixed capacitor (about 20 pf)  in series.      

Yesterday I had it percolating nicely.  Waveform looks beautiful on the Tek 465.   But it was drifting too much.  I had a cheap plastic trimmer cap in there.  This morning I replaced it with a more substantial ceramic trimmer.  This seems to have improved stability quite a bit.

I need to put some stabilizing substance on that toroid.   DeMaw prescribes Q-dope.  I'm all out.  What is the field expedient substitute?   Was it clear nail polish? 

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BITX Build: Update #2

Not much progress to report.  But I have been thinking about the filter frequency.  Here is my latest idea: 

Maybe I'll build the VFO in the 5 MHz range.  This would allow me to use the 9 MHz Yaesu filter (and associated crystals) that Steve Smith sent to me (see above).  With this I could be on 75 and 20 meters. 

I could build another filter at 13 MHz and, using the same VFO in the 5 Mhz range, get on our beloved 17 meter band.  I kind of like the idea of plug-in filters. 

You can see my ideas for the board layout.  I'm thinking of a Doug DeMaw Universal Hartley VFO inside the box shown above.   The tuning cap you see is out of an old Heath QF-1 Q Multiplier.  It has a very nice reduction drive built into the tuning shaft.  It measures 19 to 148 pf.     
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Building the BITX! Update #1

There it is guys:  A blank canvas of copper-clad board.  A clean slate ready to be filled with the components for a BITX transceiver.  As you can see, I am fighting my "build first, design/plan later" tendencies.  No real design work for me on this one (thanks Farhan!) but I am trying to plan where everything will go on the board.  (Thanks to Jim, W8NSA for the board.)   I'm going to build it Manhattan style (perhaps with an ugly dead bug or two).  I'm starting with a big board because I always seemed to end up with a shortage of space.  It looks like I can easily get all of the circuit (minus the PA) on this board.  I'll build the PA on a separate piece of copper-clad.

I'd like to build it for 17 meters, but if I stick with the 10 MHz filter that means I have to build a VFO at around 8.1 MHz.  That's not impossible, but in my experience it is easier to build simple, stable VFOs at lower frequencies. 

 

I notice that there are a lot of cheap crystals available at higher frequencies.  So, instead of keeping the filter at 10 MHz and trying to get the VFO stable at 8.1, what do you guys think about keeping the VFO in the 4 MHz range and  building the filter with crystals in the 14 MHz range? 

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Pete Juliano's KWM-4

 

Pete Juliano, N6QW, has authorized me to provide SS Daily News readers with a look at his magnificent KWM-4, a solid state version of the legendary Collins transceiver.  This project is in the Summer edition of QRP Quarterly.  Amazing job Pete! 

 

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A COOL Norwegian "S" Meter (video)

Immaterials: Light painting WiFi from Timo on Vimeo.

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Peter Parker's Video on SP5AHT's Phasing Receiver

There are so many very cool aspects of this project:  I love the phasing receiver arrangement -- it uses the same basic concept that allows my old HT-37 to generate SSB (I struggled to understand it as a kid, and finally succeeded!).   The use of the mobile phone as an audio spectrum analyzer is wonderful.  The N3ZI signal generator looks a lot like the DDS project I was working on (I should have bought N3ZI's! ).  I've been seeing these square pattern PC boards in many projects lately -- I may try this in my next project.  And of course, it is very cool to see a circuit designed in Poland being put to use by a fellow radio amateur in Australia -- a good example of the International Brotherhood of Electronic Wizards!

Here is the page for the SP5AHT rig that inspired Peter:

http://www.sp-qrp.pl/modules.php?name=Content&pa=showpage&pid=54

It is in Polish, but Google should translate it, and, in any case, we all speak Schematic!

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"Chart of Electromagnetic Radiations"

Wow, all you need to know, right here on one poster!  They even cover particle/wave duality.  I tried printing it up in hi-res but the uncertainty principle seems to be interfering! Get yours here:  http://www.flickr.com/photos/llnl/9403051123/sizes/l/ 


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Oscillo-porn! A $500,000 Oscilloscope! (video)

I don't know,  I think I like my Tek 465 better!  But if any of you guys are thinking of buying one of these, PLEASE do so via the Amazon link on my web page!

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Dipoles in Space! Millions of them!

http://www.wired.com/wiredscience/2013/08/project-west-ford/

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SolderSmoke Podcast #154

SolderSmoke Podcast 154 is available for download!

http://soldersmoke.com/soldersmoke154.mp3

August 11, 2013

-- Alligators!  Real Alligators! (see picture below -- look closely)

-- Ten meter beacon project (with Arduino and Reverse Beacon Network)

-- Telescope repair:  Chap Stick as lubricant, and the perils of macular pucker!
 
-- HW-101 saved from cannibalism!
 
-- The Wonders of WSPR and our need for instant feedback and gratification.

-- QST Review of SolderSmoke, The Book.
 
-- MAILBAG

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Kishan Has the Knack! (video)

Many of us were staring out similar windows, also dreaming of model airplanes, and of transmitter circuits, and telescopes, and rockets... This video runs only 12 minutes.  Don't be deterred if you don't speak Hindi -- the story is easy to follow.

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Who Invented the Transistor?

http://www.beatriceco.com/bti/porticus/bell/belllabs_transistor1.html

I dunno.... Roswell?  Really?  But I find myself attracted to anything that involves the use of iron pyrite and cats' whiskers in radio.  Mike, KL7R, sent me a bunch of fools gold from Alaska and it turned out to be better than galena as a detector. 

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

Homebrew Transistors (video)

So you are using store-bought transistors eh?  APPLIANCE OPERATOR!

Check out Jeri Ellsworth's very impressive production of NMOS transistors.

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

Solar Field Flip! (video)

Too bad we are not in late March.  This event has such great April Fool's potential:
Some ideas:
-- You'll have to rewind all your toroids!
-- You should switch the braid and the center conductor on all your coax!

I like the "cup half full" sentiments in this video:  The second half of Solar Max is about to begin!

Thanks to Kim VK5FJ for sending me this.






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SALE: SolderSmoke book for about $16 (save 20%)

This coupon will get you the SolderSmoke book for around $16. Valid through August 9.

http://www.lulu.com/spotlight/soldersmoke


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

Big Data and the Square Kilometer Array

All of this is very interesting, but SolderSmoke readers will probably find the last ten minutes most interesting.  

http://www.youtube.com/watch?v=dzlwhP5JejA

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

Soul in an Old Telescope

I like this telescope.  The owner built it in 7th grade and is still using it at age 70.  I'm still using the Drake 2-B that I bought with newspaper route money, so understand the sentiments.  

http://makezine.com/2013/07/29/through-a-diy-telescope-brightly/ 

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

Soul in the Old Machine: HW-101 Saved From Workshop Cannabilism

Most of our correspondents did not like the idea of me trying to convert my Heath HW-101 into a BITX-101.  But, thinking that I still might to this,  I decided to take the old rig off the shelf and see what it looked like.  I liked the looks of it -- lots of space, simple circuitry,  nice belts and gears for turning the many variable capacitors, no black box ICs.  I could see traces of my earlier repair adventures -- electrolytic caps that had been replaced, the plastic dial clutch that I'd "fabricated" myself.  Then I decided to try to fire it up. Hey, the receiver sounded very good.  Next thing you know, I was getting the transmitter going.  Then I was working DX on 20.  By the end of the afternoon, I knew there was no way I would be tearing this old rig apart.  There is simply too much soul in this old machine. 

More on this in SolderSmoke 154....

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The Viganella Heliostat -- A Village Brings in the Sun (Video)

http://www.odditycentral.com/pics/viganella-the-italian-village-that-built-its-own-sun.html

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EXCELSIOR! Happy Birthday Jean Shepherd

 

 

NPR's "Writer's Almanac" alerted us to this:    Shep was born on this day in 1925.  I realize now that that made him just a week or so older than my dad (who was a big fan).

Here is a really nice site with info about Shep, ham radio, and his call sign: 

http://www.flicklives.com/index.php?pg=318

EXCELSIOR !!!!!!!!!!!

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HB-101 ? BITX-101?

 

 

OK, so I've been wanting to build a BITX-20 for a long time.  Then Steve "Snort Rosin" Smith sent me a nice 9 MHz filter, and I started to think about using it to build a BITX 75/20.   But I don't really like 75 meters too much...  And I have this Heathkit HW-101.  I like it very much, but these rigs do not age well:  Too much heat, too many cheap components, tubes on PC boards... yuck.  I got tired of fixing it.  I've occasionally fantasized about scrapping most of the HW-101 circuitry and turning this rig into a 100 watt linear amplifier. But I didn't have the heart to do this.  Then, on the way to work yesterday it hit me:  Why not take the beautiful bi-directional circuitry of Farhan's BITX design and use that to solid state most of the HW-101?    Obviously I'd retain the finals and maybe the driver, and the CW and SSB filters.   The VFO could be transistorized.  Maybe I'd retain the tube AF amp.  I'd like to add 17 meter capability.  Pete Juliano took an HW-101 and added a digital dial (that's his rig in the picture).

 

What do you guys think?  Am I nuts?  Or would this be a worthwhile project? 

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The Nanomembrane Laser Detector Receiver

 



I like it!  Here we find some cutting edge radio technology that does not involve millions of microscopic transistors and thousands of lines of code. And it can be explained in a few paragraphs without resort to exotic math.  It even makes use of our beloved LC resonant circuit.  Quick, where did I put Billy's green laser?  And where can I get some silicon nitride? 
  
http://m.technologyreview.com/view/517336/physicists-detect-radio-waves-with-light/

Thanks to Jim, AB3CV, for sending us this.

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

Earth as seen from Saturn

Look closely.  We're the little dot.  Photo taken July 19 2013 by the Cassini probe.   People were waving!  Really:  http://www.newscientist.com/article/dn23914-shiny-happy-earth-photobombs-saturn-snapshot.html?cmpid=RSS|NSNS|2012-GLOBAL|online-news#.Ue2_i2DD-ic


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Tour of WLW 500,000 Watt Transmitter (video)

Well, you know that you are really in the high power big leagues when your transmitter requires a cooling pond, and you have to put on welding goggles before you examine your tubes!  I especially liked the bit about how they built the transmitter BUILDING from the packing materials used to ship the transmitter (my operating desk is made from a box used to ship my HT-37!). 

This is all really amazing.  They built this thing less than ten years after the initial launch of commercial broadcast radio in the U.S. 

Thanks a lot to Randy for doing this video and to the guys who gave the really excellent tour.

My apologies to the QRP purists who I know will have been deeply disturbed by this presentation.

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Oldest Drake 2B? (now with pictures)

Bill and Soldersmoke readers,

One of the earliest and still surviving Drake 2Bs is owned by Paul Brock (K4MSG) of Hamilton, Virginia.

Paul is very much into Boat Anchor Ownership and Restoration.  

 

If you are interested, look at his write-up titled “The Magic of Boatanchors” http://www.k4lrg.org/Projects/Magic_of_Boatanchors/index.html

 

 

K4MSG’s Drake 2B Receiver s/n 2052

 

In my perspective, this receiver is still an absolute “Keeper.”  

If anyone has a Drake 2B older than Paul’s,  we’d love to see it.

We have all surmised that the first 2B was serial number 2000, from the first production run back in April 1961.

Paul’s radio could have easily been one of the first receivers to hit the market.

 

Interesting sidebar; The early 2B and 2As do not have the red scale log scale adjustor button.  

 

I remember these when they first hit the market. They seemed so small compared to the Hammarlund, Hallicrafters and National triple conversion receivers from the same era.

Most Old Timers felt they were not going to get their monies worth with a tiny receiver sitting next to their big 60 to 100 Lb. transmitter.

In 1962, this was a very modern radio both in style and performance. Coupled with the Q-Multiplier/Speaker you had a superb receiver which worked extremely well on C.W., A.M. and S.S.B.

 

My first experience with the Drake 2 B came at Skyview Radio Club near the Pittsburgh, Pa area back in 1965.

 

 

 

Here is one of those early ads that show the Drake 2B without the Red Scale Slider Button.

 

 

 

 

Happy building and melting solder everyone.

 

73’s De -=WA3EIB=- Harv. Albq., NM

 

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SolderSmoke book for $16

QST gave the book a very nice review in their August edition.  But they got the price of the paper edition wrong -- it is definitely not $45!  The normal price is $20, but with the coupon code SOCIUS you can get it for $16 through 19 July. 
http://www.lulu.com/spotlight/soldersmoke

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

Grayson's Thermatron Timeline

Our friend Grayson put a lot of effort into this very interesting timeline of tubes (aka valves, or thermatrons).  Thanks Grayson!

http://hollowstatedesign.tumblr.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

book review in qst? GOT IT

Thanks to those who sent me the review.   Got it. 


I heard the August qst has a review of the soldersmoke book. I'm away
from home. Could someone email me the review? Thanks 73

"I Make Stuff" Chuck Stottlemyer (video)

More about Chuck Stottlemyer here:
http://makezine.com/2013/07/02/movers-and-makers-charles-chuck-stottlemyer/

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 Visit to the Arduino Factory (video)

Named for an Italian bar, produced by cool people in Ivrea who wield soldering irons and wear T-shirts that say "Make it Simple."  You gotta love Arduino! 

Today I will finish connecting my Arduino Uno to my Doug Demaw Lil' Slugger 10 Beacon rig.  Code (computer code!) by K6HX. 

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Knack Book News: New Blog, 25% off Sale

Our friend Grayson has launched a blog related to his new book Hollow-State Design:
http://hollowstatedesign.tumblr.com/

Over the 4th of July holiday you can save 25% on two of Lulu's GREATEST Knack-related books.  Just use the coupon code FIREWORKS when making your payment. 

For SolderSmoke:  http://www.lulu.com/spotlight/soldersmoke

For Hollow-State Design: http://www.lulu.com/shop/grayson-evans/hollow-state-design/paperback/product-20987562.html


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 Society for Model and Experimental Engineers

Wow.  Stop what you are doing and take a look at the four short films about a group of intrepid British knack victims.  Very nicely done.  Really captures the allure of the shack/workshop.

http://makezine.com/2013/06/28/the-makers-of-things-2/




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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

Dutch Knack During WWII

 

 

There is a very nice article on the MAKE blog this morning: 
http://blog.makezine.com/2013/06/06/an-early-maker-story-from-holland/
 
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

Quote of the Day: On Tinkering

Finally, some justification for my "build first, design later" method:

"Contraptions, machines, wildly mismatched objects working in harmony -- this is the stuff of tinkering.  Tinkering is, at its most basic, a process that marries play and inquiry."

from www.exploratorium.edu/tinkering   Quoted in Massimo Banzi's book "Getting Started with Arduino."

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

Alan Yates, VK2ZAY, is back in the knack!

I was getting kind of worried.  I hadn't seen any new articles on Alan's excellent web site.  But on my last visit I learned that he has moved to Seattle and is going to Maker Faires:  http://www.vk2zay.net/article/268

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

Save 20% on Knack Books

Codeword: GLOW.   Very appropriate for Grayson's Thermatron book: 



http://www.lulu.com/shop/grayson-evans/hollow-state-design/paperback/product-20987562.html


And also for mine (tubes, QRP fireflies and all that):



http://www.lulu.com/spotlight/soldersmoke

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

1-29 MHz In One Small Box

 

This weekend I put the Arduino/AD9850 Direct Digital Synthesis device into a box this weekend.  It is sort of evolving into a general purpose HF signal generator and/or VFO.  It is really kind of neat that this little collection of boards can generate RF across that range, with accurate digital readout.  Thanks again to Richard Visokey, AD7C, for the circuit and the code.  As you can see, my cabinet making skills will never land me a job on the Discovery Channel,  but I'm kind of pleased with the box.  I picked up the wood panels from a hobby/craft shop. 



 

 

I left a lot of space in the box.  I envision an amplifier taking the output from its current .4 milliwatts up to around 10 milliwatts, followed by step attenuators (pads).

 

Here is the other end.  Of course, I could have just taken the ATMega chip out and avoided putting the whole Arduino board inside the box, but I'll leave that exciting digital adventure for a future project.


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

Simple Homebrew SDR

I know that "simple" and "homebrew" aren't the words that come to mind when we think of Software Defined Radios, but minimalist guru Peter Parker, VK3YE, reminds us that with little more than an antenna, a diode, a crystal oscillator and a connection to the computer soundcard, you can dive into the world of SDR. 

I've been doing this for some time now, but my receiver uses a 40673 dual gate MOSFET and a universal VXO from George Dobbs, G3RJV.  I've been running mine with the FLDIGI and JT-65 HF programs.  Peter's video alerted me to the charms of SDRadio from Alberto, I2PHD.  This is a very nice program.  Of course, I'm always happy to add a dash of Italy to my operations.  Thanks Peter!  Thanks Alberto! Thanks George!


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

Cliff Stoll DEFINITELY has The Knack! And he Kluges!

 

The Maker Blog has a nice article on Cliff Stoll, the author of "Silicon Snake Oil" and "The Cuckoo's Egg."   I liked Cliff's books and included quotes from them in "SolderSmoke -- Global Adventures in Wireless Electronics."  I was glad to see that Cliff is doing well and still tinkering.  Be sure to check out the video on his R/C fork lift.  FB OM.

I was, of course, very intrigued by the slide showing the symbol of the "KlugeMeisters of America." Can we get a pronunciation ruling from Cliff?  Can we nominate people for induction into the KMA?  

In Spiritu Klugo!  Non Vacuo Sine Glyptum!  Words to live by,  my friends...  Patrick Murphy explains all this here:  http://www.cv.nrao.edu/~pmurphy/kluge_where.html 

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

Ham Radio, the tsunami, HW-101, Tek 465, BITX-20

I know many of you guys have seen this before. And I know that Farhan is tired of seeing it pop up again and again.  But it just appeared on my Facebook page today and I watched the whole thing and saw things I hadn't noticed before:  There's a Heathkit HW-101 (or maybe its an HW-100).  There is a Tech 465 oscilloscope. There is a BTX-20!  

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