Knack Story: Ryan's Rig

Bill,
      
... [I know] a young ham locally who suffers terribly from the
affliction of the "knack". Ryan, KJ6HBY, is 17, and an Extra class,
who earned his DXCC in a year. He is a great builder, starting out
building his first antenna a couple years ago by breaking apart an old
washing machine motor and unwinding it for the wire. Along the way he
has restored various rigs, i.e. HR10, S-38, IC707, etc and built a
BTX17 (17 meter version of the BTX20). Enclosed is a couple photos of
his latest creations. First, he hand carved a wood morse code key. It
actually feels and works well. Now he has build a single tube xmtr,
and after fussing with it, is pumping out 4 watts. Both of the kid's
folks are hams as well as his sister. I had an opportunity to visit
his shack the other day. It's a teenage ham's dream and a mother's
nightmare. Racks floor to ceiling with radios! If anybody has the
knack, Ryan does. Makes me think there is a future, we can sleep well
tonight.
73
Mike Herr
WA6ARA
DM-15dp
Home of The QRP Ranch

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

But Why Did Swamping Resistors Cure JBOT Oscillations?

OK,  so as I mentioned in SolderSmoke 148 (apprently with screeching in the background -- sorry) I managed to tame a bad JBOT oscillation problem by placing 680 ohm resistors across the primaries of the broadband transfomers in the JBOT.  Now I'm wondering how/why this worked, and what we could do to make this kludge unnecessary.  

Am I correct in suspecting that at the problematic frequency of 250 kHz, the one or more of the tranformers are self resonant, and that the resistors just bring down the Q of the -- in effect -- tuned circuit?  This lowering of Q makes feedback and oscillation more difficult, right?  

Here is the background.   Read from the bottom up.   

There is an old saying in Spanish:  "No hay mal que por bien no venga."   More or less this is the same idea as: "Every dark cloud has a silver lining."  Well, the dark cloud was my techno-agony with the parasitic oscillations (see my plea for h elp from yesterday).  The silver lining was the e-mail from Edgardo, LU1AR, in Buenos Aires that helped me get rid of them.    Edgardo advised putting a resistor across the primaries of the JBOT amplifier stages.  This is an old "lower the Q" trick, the idea being that lowering the Q might help prevent the amp from self-oscillating.     I used 680 ohm resistors.   First I put one across the primary of Q1.  No joy. Then Q2.  No luck.  Then I put one right across the primary of that big output transformer.  That did it!  The parasitics disappeared.   And I still get a nice 4 watts of output.  Thanks Edgardo.  I hope to make a contact with this rig today. 

The real silver lining in this story comes, however, in the form of Edgardo's blog site.  Wow, what an inspiring example of Argentinian Knack.  Radios, telescopes, auto-giros.  This guy is also into homebrew DSB rigs.  Wonderful stuff.  Check it out.  (Google will translate it for you, if necessary, but even if you don't read Spanish, the pictures tell most of the story.) 

http://www.lu1ar.blogspot.com.ar/

I put this URL blog up on the SolderSmoke blog.  

Thanks to all who sent advice and encouragement.  Merry Christmas! 

--- On Sun, 12/23/12, lu1ar  wrote:

From: lu1ar
Subject: [BITX20] Re: JBOT taking off at 250 kHz
To: BITX20@yahoogroups.com
Date: Sunday, December 23, 2012, 9:56 PM

First. You must secure the RF decoupling of +B line. Use a bunch of small capacitors in paralell 1n and 100 nF with 22 uF electrolitic.
Second: Use 1Kohm resistor in paralell with primary of the transformers. Begin with the driver, then the 1st amplifier and then the output transformer.
Let us know results.
Regards.
Edgardo Maffia LU1AR
Buenos Aires - Argentina

--- In BITX20@yahoogroups.com, "iam74@..." wrote:
>
> 
> 
> --- In BITX20@yahoogroups.com, Bill Meara wrote:
> >
> > I'm building my FOURTH JBOT and this one is giving me more trouble than all the others combined.   I seek the help of the group. 
> > Here are the details of my tale of woe:
> > 20 meter rig.  Double Sideband.   The JBOT is fed by a simple two-diode, trifilar toroid singly balanced modulator.  NO DIPLEXER TO SPEAK OF.  At the output of the balanced modulator there is a 1000 uH choke to ground and a .001 uF cap to the input of the JBOT.  AF amp is an LM-386.  VXO is a very simple MPF-102 one stage ceramic resonator VXO with no buffer stage.  7 element low pass filter (three coils, four caps). 
> > All the transformers are wound on FT-37-43 cores.  T3 is four such cores stacked 2X2.
> >  
> > The arrangement works beautifully into a 50 ohm dummy load.  But as soon as I connect it to an antenna (a dipole out in the yard, fed with 50 ohm coax) the output signal gets ugly.  
> > Looking at it on the scope, instead of the nice figure eight pattern (similar to the two tone test pattern of SSB) I get ugly fuzzy outcroppings from the peaks.  Looking at the signal more closely I can see that in addition to the 14.2 Mhz signal, there is another LF oscillation at around 250 kHz. 
> > I've been struggling with this.  I can't get rid of the LF oscillations. The leads are all short and the inputs are far from the outputs.   I've beefed up shielding, and decoupling.  I've sacrificed a chicken to Papa Legba. Nothing seems to help.  
> > I THINK the feedback/oscillation is taking place in the JBOT itself -- not through the
> > audio amp or the balanced modulator or the VXO.
> > I watch the RF and the AF inputs to the balanced modulator to see if there is any difference between the stable situation (with the 50 ohm dummy load) and the unstable situation (with the antenna),  I don't see any differences. 
> > I even put an antenna tuner between the final and the antenna anb made sure that the antenna looks like 50 ohms non reactive.  This seems to help a bit, but the ugly instability is still there. 
> > Help me! 
> > 73  Bill N2CQR    
> >
> 

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Move over Altoids Tins! Legos for Raspberry Pi Case

Too bad the Raspberry Pi board is a bit too big for our beloved Altoids tins.  It would have been a very fitting match:  British board in a British box.   A twelve year-old has solved the problem with Legos:  http://blog.makezine.com/2012/06/11/lego-raspberry-pi-enclosure/
Will this lead to raids on the toy boxes of the grandchildren of SolderSmoke fans? 
Billy's RasPi is running nicely (but no Legos for him).   

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Signal Generator Ideas

Hi, Bill

Howzabout a generator that goes from 1 Hz to 40 MHz with 1 Hz resolution, adjustable cursor so you can step any of the 8 digits, presettable offsets for if frequency, repeater offset, or r.i.t., directly synthesized output so almost no phase noise and 12 bit waveform accuracy? How about a price tag of less than $20 for all the major parts? Start by Googling dd_synth.asm for control software, and rather than buying the PCB recommended in the notes at the head of the program, search for AD9850 on Ebay for the synthesizer board and LCD 16x2 for the display. A 16f628a PIC is a couple bucks. Both the display pinout and the synthesizer pinout match standard perfboard. For a little more than $10 more get the AD9851 board and the upper frequency limit is 60 MHz.

A better way to transistorize the old tube-type generator is to use a dual-gate RF mosfet for the oscillator. You can trim the gain for waveform purity by adjusting the bias on gate 2. Once you find the optimum bias on each band, diode-switch the bias level with the bandswitch. Since gate 2 has an extremely high impedance you can use resistors in excess of a megohm, so it won't affect the Q of the tank coil.

Jim Daldry
Raleigh NC

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Opening Scene of Contact (CQ at the end)

Mike Herr's video on his use of an Arduino to call CQ SKN made it onto Hack-A-Day 
yesterday and provoked some discussion there of the meaning of CQ.  One fellow posted 
this opening scene from the movie Contact.   I thought you guys would like it. 

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Arduino Does Straight Key Night

Bill,
     Hope a good Christmas and excellent New Year. Here at WA6ARA we had a blast for Straight Key night . In the past I have used new keys, old keys and multiple keys. This year we celebrated SKN with a little twist. At Pacificon I purchased a hugh CW key, all made out of wood, about 3 times the normal size J-38. This isn't a QLF key but a piece of beautiful wood working, and fully functional. This was my main key for SKN.
But SKN can require the sending of CQ SKN for a considerable amount of time. Normally a programed keyer would do the job fine. But this is not in the true spirit of SKN, the use of the straight key. So, using a trusty Arduino board and a few lines of programming,  I solved the practical and ethical problem. The Arduino drives a model airplane servo. The servo is positioned such that it's arm presses down on a miniature J-38 key, thus sending the "CQ SKN". Also the miniature J-38, about half size, sort of balances out the larger size of the
hand key, and keeps the universe in check. I've enclosed a short youtube for your viewing enjoyment

http://youtu.be/Rn7Ky9Ib7ug

73
-- 
Mike Herr
WA6ARA
DM-15dp
Home of The QRP Ranch

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

Like a Hamfest, but kind of EVIL

For a look at how the hackers do their version of the Dayton ham-vention, check out this video on DEFCON:   http://vimeo.com/56234900

Looks sort of like "Four Days in Hell" to me!  Finally, a group that makes hams seem normal and well-balanced! 

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A Nice Hallicrafters S38-E Knack Story

Bill - 

It was Christmas of 1958 (5th Grade)that my parents bought me the Hallicrafters S38-E that I still have.  I was recovering from multiple surgeries the previous summer to correct for the effects of Polio when I was 3.  I came down with Polio in the last year before the vaccine was released to the public.  

A bit of bio - because of my physical limitations as a child, I spent a lot of time indoors reading and listening to the radio.  Broadcast AM here at that time was still playing dramas like "The Lone Ranger" and "Big John and Little Sparky".  I really enjoyed them.  Then, on that fateful day I asked my mother why, since our radio plugged into the wall electric outlet and we could hear people talking, weren't other people able to hear us talking on their radio if we spoke into the loudspeaker.  She said, 'I don't know, but the library ( 2 blocks away) will have books about radio that you can read."  The Knack bit early and it bit hard.  

By the time I was in 5th grade I had discovered short wave radio.  I dearly wanted a short wave radio and I wanted a Hallicrafters.  Somewhere I had found a catalog and wow! nothing else would do.  What I didn't realize until I was in my teens was just how hard times were for my folks.  Most families then did not have medical and hospitalization insurance.  My dad was paying off the hospital and the doctors every month almost until I graduated from high school.

But, anyway, I did get the S38-E for Christmas.  At $69.95, it was the least expensive Hallicrafters available.  In reality, it is just an All-American - 5 with extended tuning range.  Tuning was as broad as a barn door, and above 15 MHz it is as deaf as a post.  But it was mine and I loved it.  The short wave bands were still hot in those days as we were just peaking through one of the most celebrated Solar Maxima of the last century.  Many the hours I listened to HCJB - Quito, and Radio Moscow, and Voice of America....   I also found people talking to each other - Wow!  Ham Radio.  And just look at me now.... And those strange beeping sounds - that was actually people talking? And what was that strange Donald-Duck sounding talk all about?

Yes - I still have that same S38-E.  It went to college with me, and has been with me for over half a Century, now.  Yes, it still works. (Needs a replacement IF transformer),  Yes, it will shock the bejeebers out of you if you plug it in wrong.   {I use two filament transformers back-to-back to prevent that.)  Yes, the Knack still has me, but that's another chapter.

72's 
Bruce  KK0S

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High Pitched Audio QRM in SS #148

Two listeners blessed with good high frequency hearing alerted me to the fact that the latest podcast had some annoying high pitched noise in the background.   Peter, VK2TPM was the first to report it -- he sent along the above spectral analysis of a gap between words.  Steve,  W1KF,  also heard it, and provided a clue that I think solved the mystery.  

Steve noted that the noise was not present during the sponsor ads that were included in this episode. 
That let me figure it out.   On Saturday when I was recording this,  I got through about half the show when the power went out (that happens a lot here).  The battery in the laptop I was using to record the podcast saved the day and no data was lost.  The power came back on within a few minutes, but the outage had turned off the main PC in the shack.  That PC (AND ITS FAN) remained off when I was recording the ads.   I did the same kind of noise removal processing that I always do, but this time the noise sample that I used was taken from the mic with the main PC (AND ITS FAN) turned off.  My guess is that the whine from the fan (which I can't hear due to tinnitus) didn't make it into the noise sample, and thus didn't get removed from the podcast audio.    I went back and did a couple of rounds of noise removal and low pass filtering.  I think (I HOPE) I got rid of the offending noise. 
I have uploaded a new and hopefully improved version of the podcasts.  Audio reports will be appreciated.   

One of my New Years resolutions is to improve the technical and substantive quality of the podcast. 

Thanks Peter, Thanks Steve. 

Happy New Year to all! 
  
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SolderSmoke Podcast #148

SolderSmoke Podcast #148 is available:
http://soldersmoke.com/soldersmoke148.mp3
December 30, 2012

SPONSORED BY usedradiomall.com

-- Hurricane Follow-up
-- Subliminal Mind Control to Encourage Homebrewing (beep-beep)
-- The Shortcomings of the All American Five Receiver
-- Solid-Stating a Heath SG-6 (with Farhan's circuit)
-- VK3YE's Beach DSB Rig
-- Tek 'scope connection to frequency counter
-- Mod to W7ZOI/W7PUA power meter
-- JBOTing my 20 meter DSB Rig -- A Tale of Woe
-- LU1AR "The Most Interesting Ham in the World"
-- Billy's Raspberry Pi
-- Latest QST, SPRAT, Hot Iron
-- Videos: Landfillharmonica,  Knack in Sierra Leone
-- Santa delivered a Soldering Station
-- MAILBAG

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He Should Have Used a Low Pass Filter!

http://www.sun-sentinel.com/news/broward/hollywood/fl-pirate-radio-hollywood-20121229,0,5142922.story

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 Christmas Present from Argentina

There is an old saying in Spanish:  "No hay mal que por bien no venga."   More or less this is the same idea as: "Every dark cloud has a silver lining."  Well, the dark cloud was my techno-agony with the parasitic oscillations (see below).  The silver lining was the e-mail from Edgardo, LU1AR, in Buenos Aires that helped me get rid of them.    Edgardo advised putting a resistor across the primaries of the JBOT amplifier stages.  This is an old "lower the Q" trick, the idea being that lowering the Q might help prevent the amp from self-oscillating.     I used 680 ohm resistors.   First I put one across the primary of Q1.  No joy. Then Q2.  No luck.  Then I put one right across the primary of that big output transformer.  That did it!  The parasitics disappeared.   And I still get a nice 4 watts of output.  Thanks Edgardo.  I hope to make a contact with this rig today. 

The real silver lining in this story comes, however, in the form of Edgardo's blog site.  Wow, what an inspiring example of Argentinian Knack.  Radios, telescopes, auto-giros.  This guy is also into homebrew DSB rigs.  Wonderful stuff.  Check it out.  (Google will translate it for you, if necessary, but even if you don't read Spanish, the pictures tell most of the story.) 
http://www.lu1ar.blogspot.com.ar/
Thanks to all who sent advice and encouragement.  Merry Christmas! 

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

Woe is me! Why Podcast is Late: Parasitic Oscillations!

I'm building my FOURTH JBOT and this one is giving me more trouble than all the others combined.  
Here are the details of my tale of woe:
20 meter rig.  Double Sideband.   The JBOT is fed by a simple two-diode, trifilar toroid singly balanced modulator.  NO DIPLEXER TO SPEAK OF.  At the output of the balanced modulator there is a 1000 uH choke to ground and a .001 uF cap to the input of the JBOT.  AF amp is an LM-386.  VXO is a very simple MPF-102 one stage ceramic resonator VXO with no buffer stage.  7 element low pass filter (three coils, four caps). 
All the transformers are wound on FT-37-43 cores.  T3 is four such cores stacked 2X2.
 
The arrangement works beautifully into a 50 ohm dummy load.  But as soon as I connect it to an antenna (a dipole out in the yard, fed with 50 ohm coax) the output signal gets ugly.  
Looking at it on the scope, instead of the nice figure eight pattern (similar to the two tone test pattern of SSB) I get ugly fuzzy outcroppings from the peaks.  Looking at the signal more closely I can see that in addition to the 14.2 Mhz signal, there is another LF oscillation at around 250 kHz. 
I've been struggling with this.  I can't get rid of the LF oscillations. The leads are all short and the inputs are far from the outputs.   I've beefed up shielding, and decoupling.  I've sacrificed a chicken to Papa Legba. Nothing seems to help.  
I THINK the feedback/oscillation is taking place in the JBOT itself -- not through the
audio amp or the balanced modulator or the VXO.
I watch the RF and the AF inputs to the balanced modulator to see if there is any difference between the stable situation (with the 50 ohm dummy load) and the unstable situation (with the antenna),  I don't see any differences. 
I even put an antenna tuner between the final and the antenna anb made sure that the antenna looks like 50 ohms non reactive.  This seems to help a bit, but the ugly instability is still there. 
Help me! 
\

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LadyAda Named Entrepreneur of 2012

Watch this video and you will see that Limor Fried has The Knack!
She and her company have brought homebrew electronics back to lower Manhattan.
Some kind listener sent me a gift certificate for Ada Fruit.  We will put it to good use, probably
with Raspberry Pi and Arduino gear.
Three cheers for Lady Ada!

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Roadkill Violins! LandfillHarmonic

Landfill Harmonic film teaser from Landfill Harmonic on Vimeo.

Wow, this is a really inspiring video about being inventive, overcoming obstacles, using what you find and putting junk to good use.  I thought you guys would like this (ESPECIALLY ROBERTO!).

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FITSAT-1 Flashing Morse With LEDs from Orbit

Very cool:  Japanese students sent up a small satellite.  One of its capabilities is to flash Morse code messages in the visible light range using LEDs.   Prepare to peg your geek meter: 
http://www.fit.ac.jp/~tanaka/fitsat.shtml 

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PE1JXI's BITX-20 Handheld

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Watching a Light Beam at One Trillion Frames per Second

Billy alerted me to this TED Talk presentation on an MIT Media Labs project that used new "femto photography" techniques that allow us to watch -- in VERY slow motion -- a light beam pass through a bottle. Amazing. Makes me think about Einstein's old thought experiment about running alongside a light wave (but of course here they are slowing down time...)

 Here are some details on how they did this:
 http://web.media.mit.edu/~raskar/trillionfps/ 

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African Knack

Thanks to Allan, WA9IRS, for sending us this inspiring video. Just the right touch for Thanksgiving. This kid is definitely one of us. Let's try to think of ways to help him. Parts box? Radio books?

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Get SolderSmoke For Christmas! 30% off (23-27 Nov)!

Use the little mail icon (below) to forward this to those who are buying you things for Christmas!   30% off if you buy 

23-27 November.    Here are books: 

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

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NA5N, a Solar Flare, and the Very Large Array

I think I said before that Paul, NA5N, has one of those "dream jobs" for a radio amateur.  Confirmation of this came in a message he posted to QRP-L today: 

We're running a special experiment today using the VLA antennas to observe at 74 MHz (a protected radio astronomy band) and at 327 MHz.  We've hung dipoles just below the antenna subreflectors, acting as a virtual ground, and of course the 88ft dia. dishes to illuminate the dipoles.  Picks up a lot more power from the sky than I would have thought (about 30dB gain over the same dipoles in free space). 
Anyway, about 0830 MST, suddenly the system temperature climbed about 200 deg. K.  Our switched power calibration injected into the LNAs showed no shift, meaning the jump in power came from the sky, not from the electronics.  The power plot looked just like a solar flare.  Checked the NOAA site, and sure enough, we had an M4 solar flare from region 1618 ... about smack in the center of the sun.  About 1530UTC=0830MST=1030EST, Wed. Nov. 21. 
NOAA has since measured the shock wave from the CME at 1918 km/sec.  This is a fairly strong shock wave, and coming from the center of the sun means planet earth will be pretty close to the bulls eye. 
The first time in my life I witnessed a major solar flare in real time watching the "sky power" plots.  Pretty neat.  First time the astronomers involved in this experiment have witnessed a solar flare as well real time. 
Region 1618 has produced numerous C- and M-class flares past couple of days with high potentials of future activity.  This will ionize our E/F layer for elevated MUF and weak signal reflection.  Check the bands if you're not at work. 
This 1918 km/sec. shock wave headed for us will almost assuredly trigger a major geomagnetic storm in a couple of days.  If it hits Friday evening, it will trigger likely aurora over northern U.S.  It may hit Saturday.  I'll check the NOAA predictions later today and post as to the expected shock wave arrival. 
72, Paul NA5N
Socorro, NM
Currently inside of VLA antenna #5, west arm.
http://www.vla.nrao.edu/ 

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Another VK3YE DSB Rig

Hi Bill

       A short e-mail from across the pond. Thanks for sharing the VK3YE link, so impressed I was that I have built one. 

It receives great and puts out a nice looking dsb signal, looking forward to some good qso's, ready to improve on it as we speak and looking to make a top band and 18m version also, love the site and keep up the good work...Ian

Ian Miller

G7FFV

UK

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"Road Kill" Batteries for Us?

http://news.nationalgeographic.com/news/energy/2012/11/121116-second-life-for-used-electric-car-batteries/


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Schematic of the VK3YE "DSB-On-The-Beach" Rig

Peter Parker's amazing 8 transistor DSB rig (featured in an equally amazing YouTube video -- see earlier blog post) has sparked a worldwide resurgence of QRP minimalism.  There is now a lot more activity on the "Minimalist QRP Transceivers"  Yahoo group (be there or be square).   Steve "Snort Rosin" Smith WB6TNL is minimalist mentoring to the max -- with his help it looks like more VK3YE transceivers will soon be on the air.  Steve was kind enough to take the info from Peter's video and turn it into a .pdf schematic (see above).  It is in the file section at the Minimalist QRP Transceivers group.  I was, of course, pleased to see the inclusion of a robust 7 element low pass filter.  

Michigan Mighty Mites are also tickling the ether.   I may pull out my single MPF-102 Yingling 80 meter rig.   You can join the Minimalist group here: http://groups.yahoo.com/group/Minimalist_QRP_Transceivers/

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Uncle Sam Wants You! (Well, really your Telescope)

 I don't think they will be that interested in my $50 Tasco 4.5 inch reflector, but I am thinking about sending in a proposal for a 1.2 million dollar series of upgrades for the old 'scope!

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A Promising Start for the SG-6 Solid State Conversion

We have kind of half a holiday today -- I have the day off, but the kids went to school.  I made use of the additional shack time to test the feasibility Farhan-izing my old, not-so-beloved Heathkit SG-6 signal generator.  I did a quick Manhattan build of the oscillator section from Farhan's sig generator (link in yesterday's post).  Using an idea from an old 73 Magazine article on a similar project (thanks Clint!), I smashed the tube (appropriate, don't you think?) and connected (using the glass stump!) Farhan's oscillator directly to the pins that lead to the switchable coils and the variable cap of the SG-6.    I just wanted to see if it would oscillate, and see if there was a big change in SG-6 dial calibration.  

Wow, it worked great!  It oscillates very nicely on all but the upper frequency band setting (20-50 MHz).   I feel confident that I'll get it to oscillate at least up to 30 MHz.   Next I'll build Farhan's buffer and amplifier stages.   The SG-6 had a switchable attenuator -- I want to include that feature in the solid state version.  I'll have to give some thought to the audio modulation feature (nice for aligning AM receivers). 

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Solid State Conversion for a Heath SG-6 Signal Generator?

I've recently become acutely aware of the shortcomings of my signal generator. 
It is a Heathkit SG-6.  It is really old.  It has a selenium rectifier in it. It has one of those old mic connectors on it for the output.  The output is very low.  But I like the cabinet and there is a nice switchable coil/variable capacitor LC circuit in there (see above).  

In 2008 in Hyderabad, India Farhan went to McDonalds with his kids and went home with some straws.  Soon the straws are chopped up and turned into coil forms for a signal source:  http://www.phonestack.com/farhan/siggen.html

So here is my idea:  de-tube the SG-6.  Turn the selenium over to the HAZMAT authorities.  Save the coils and the cap and most of what George Dobbs would call "the socketry."  Use an MPF-102 for the oscillator, then make use of the buffer and feedback amp from Farhan's soda straw circuit. 

What do you guys think? 

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8 Transistors = 40M DSB XCVR (on an Australian Beach)

Another brilliant rig from DSB guru Peter Parker, VK3YE.  I really liked this one.
I loved his drawing of the circuit diagram -- right there on the beach! Lots to be learned from this video.  Thanks Peter!
 
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The Hobbit Hole of QRP

In SolderSmoke 147 I mentioned that I had found some old pictures of AA1TJ's underground hamshack and workshop.  People wrote in asking me to post them.  Here they are.  I still can't find the shot of the door surrounded by snow. 

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Lights and TV during blackouts! My Inverter ($69)

People have been asking about the DC to AC inverter that I have been using during the now frequent power outages (5 in the last two years, two of them since July 2012).  With it I can easily keep the lights on in the house and even run the TV.  Not bad for $69.  Here it is:

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Solder Smoke Podcast #147 -- Hurricane Sandy Edition

Hurricane Sandy backup station at N2CQR

SolderSmoke Podcast 147 is available for downloading: 
http://soldersmoke.com/soldersmoke147.mp3
October 29/30 2012
Hurricane Sandy on the way
Thanks for birthday wishes 
Einstein -- a very nice fellow with a bit of the Knack
Rocket project update
808 key chain cameras (thanks for the Amazon support!) 
Audio output transformer for Barbados Barebones RX
Mighty Midget RX -- breaking it, fixing it (with help from friends)
Freq counter connection to Tek scope  
Halli S-38E -- How to avoid electrocution?
The HQ-100's anti-drift alarm clock 
Book Review:  "Instruments of Amplification" by H.P. Friedrichs (5 Soldering Irons!) 
BANDSWEEP: 20 meter SSB via DC receiver on hurricane day
Report on outcome of the hurricane -- inverter saves the day (really the night)
MAILBAG (a big one).    

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All OK at SolderSmoke HQ

Hurricane Sandy went through here yesterday. We had a lot of water and wind.  Power went out at about 7 pm, giving me the opportunity to display my technological prowess by deploying my 1.1 kilowatt DC/AC inverter.   It worked very well -- we had lights and TV, and were the envy of the neighborhood.  We all went to sleep on the ground floor -- trees are the real hazard here.  We were very pleased to be awakened by the lights coming back on at 1:20 am.  Three cheers for Dominion Power!   I hope listeners in the storm's path had it as easy as we did.    

Podcast #147 will be a special Hurricane Sandy edition.  I should have it out in a day or so. 

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Waiting for Hurricane Sandy

That vortex off North Carolina is Hurricane Sandy, and it is heading right for us.  It should make landfall tomorrow, perhaps in Southern New Jersey, perhaps closer to us (the location of the landfall of the eye doesn't matter much -- the wind field has a radius of 300 miles!)   It could really mess things up  --- lots of water, lots of wind, and it will collide with a cold front moving in from the west.  Yuck.   There is a good chance we will lose power.  I have pulled out my trusty Heathkit HW-8 and my solar-charged gel cell battery, so I am ready to go.  Good luck to all those in the storm's path.   

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Good News From Ireland!

Hi Bill,

I'm not sure what's in your sacrificial solder but it sure is good stuff!!!

I received my results today and I'm very very pleased to say I passed.

Now I can finally set my mind to building a shack...

I'm going to celebrate by ordering one of Tim Walford's excellent looking beginner kits and I've just started building Tony Park's Ensemble RXTX.

I'm not sending in my cert just yet though as I want to pass my morse test first.

Thanks again for the kind support, I'm sure it got me a good few percent on the test!!

Also thanks to Steve Smith WB6TNL and his words...

"Thousand of people have taken this examination and passed. There is no reason why I cannot also pass."

He was right!

Also I hope Dave passed, unfortunately I didn't get to meet him at the exam, hopefully we'll figure out how to contact each other, it'd be good to have a newly passed fellow ham to share ideas with.

Regards, or should that now be 73 :),

Chris

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"Zen and the Art of Radio Telegraphy"

OM Carlo Consoli, IK0YGJ, has produced a nice book on radio telegraphy.  Very much in the spirit of the International Brotherhood of Electronic Wizards, he has made it available in Italian, English, French and German.  I have started a refresher language course in Italian and intend to use Carlo's book as reading material for the course (my instructor will be sympathetic because her son is a radio amateur).  Who knows, I may be able to improve my Italian and my CW at the same time!    

Check it out:  http://www.qsl.net/ik0ygj/enu/index.html

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The Joy of Tinkering at RIT

Our Dayton corrrespondent Bob Crane, W8SX, sent us this. Thanks Bob!

http://www.edn.com/design/test-and-measurement/4396825/The-Joys-of-Tinkering?cid=EDNToday

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Something Different: Stop Action Movies

The stop-action film Frankenweenie is hitting the theaters here. Its mad scientist/workshop theme seems to have some Knack relevance. This morning I found this five minute film called "The Maker." I thought you guys would like it. I also liked the video (below) about some of the homebrew gear that they used to make The Maker.

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Harv's Hallicrafters HT-37: A Thing of Beauty

Good Evening Bill,

Well with sore fingers, I’m glad to report that the upper deck of my newly acquired HT-37 is complete. (see enclosed photos)

Mice had a small party in this radio but aside from the numerous corrosion spots and few frayed wires,  the task of restoring was not too over whelming.

I have had my trusty Soldering Iron in high use mode lately.

All but the final tubes have the Hallicrafters logo stamped on them.

I had to replaced the Final Tune Capacitor C55 and have gone through all the modifications done to this radio during its 52 years of service.

The previous owner added an internal Antenna Relay (grey transformer near rear of deck.) and replaced the Mic connector with a Drake style phono jack. (I guess that’s acceptable.)

Now I’m onto the re-capping of the lower deck, De-ox the tube sockets and switches. Finally, the replacement of the rectifiers with solid state devices.

I’m documenting all the details just in case there is another solder melting soul out there that wants to restore their HT-37.

With some tender care, it should last another 50 years.

Bill, Keep on learning, Keep on burning (solder that is!)

73’s & Enjoy

Harv -=WA3EIB=-

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My Mate for the Mighty Midget

Al, W1UX, asked for a picture of the receiver that I used to listen to his dulcet tones this morning.   Here you go Al.    Here is an article on the project: 

http://www.gadgeteer.us/erart.htm

Above is the Mighty Midget RX paired up with a DX-60 and a VF-1 (circa 1998)


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W1UX

Now THAT'S a ham shack! My Mighty Midget receiver allowed me to listen in this morning to Al, W1UX, and friends on 75 meter SSB. One of Al's AM operating positions appears above.  Note the DX-100.  And the R-390 (want one).  And the Tek 465. I've been a big fan for years.  Check out Al's boatanchor web site:    http://www.tinyradio.com/boatanchor01.html  

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Mighty Midget RX on a Key Chain

The key chain device will soon be carried to 1200 feet by our new rocket.

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