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!

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

Dipoles in Space! Millions of them!

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

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 #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

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

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.

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

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

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

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 !!!!!!!!!!!

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

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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