Two Videos from Farhan's Visit (more to follow)

 

Farhan Visits Northern Virginia En Route to FDIM (Videos to Follow)

Mike KD4MM, Farhan VU2ESE and Dean KK4DAS

Farhan VU2ESE was in Northern Virginia this week, on his way to the Four Days in May Event at the Dayton Hamvention.   We had a great visit with Farhan.  We took him out to the Thomas Jefferson High School for Science and Technology where he shared with the students tribal wisdom about building CubeSats and about building simple direct conversion receivers.  Farhan's use of direct conversion receivers to teach homebrewing to students in Hyderabad inspired our efforts in Northern Virginia.  We often referred to Farhan when speaking to the students here, so it was really great to give them a chance to talk to him directly. 

From the high school we went to the local restaurant at which Vienna Wireless has its weekly lunch. Many of the people at this lunch are also members of the VWS makers group.  This was a lot of fun. 

Don KM4UDX even brought in his somewhat eccentric build of the uBITX transceiver designed by Farhan.  Don's rig is labeled "The uBITX of Life."  It has also been called "The Franken-uBITX." Whatever the name, Farhan was clearly pleased to see Don's handiwork. 

I shot a lot of video during Farhan's visit (last time I failed to do this and regretted it).  I will put these videos up on the SolderSmoke YouTube channel during the days ahead. 

Thanks Farhan! 

SolderBaloney and SolderTruth

This is so nuts that it actually had me checking to see if this was possibly an April 1 joke.  But alas, it was put out on March 30 and is apparently quite serious.  Rogier PA1ZZ sent me this.  I think his reaction was the same as mine.   My message to Rogier: 

Ha!  He misses the key point:  HOW MANY OXYGEN MOLECULES ARE IN THE SOLDER?   Here at the SolderSmoke Laboratories we only use oxygen-free solder.  And wire.  Sounds MUCH better.  Just kidding.  I think this is audio-fool  hogwash.  I'm sure my friend Ron WA6YOU (a real solder expert) will agree.    How dare this guy in the video besmirch the name of good ole 60/40 Kester!   And even at the local high school, Dean and I were pleased to find that all the students and their teacher had already REJECTED lead-free solder.  Also, this guy seems to think that the lead has been replaced by silver.  Dude, that would be some expensive solder!   His explanation of rosin is, I think, kind of shaky.  Thanks for sharing Rogier.   73  Bill 

Next I suppose we'll have recommendations on how different solder mixes can produce different audio effects:  "For a more mellow sound, go with 60/38 and 2 percent copper!"  

I immediately sent this to my friend Ron WA6YOU, a noted expert on this subject: 

Ron's response: 

OMG!!!!!  I don't know where to start and I haven't even had breakfast yet.  First off Sn60/Pb40 contains NO silver and melts at 361 F and yes I do have my irons in class set to 800 F.  Today in my classes I use Sn63/Pb37 since it is Eclectic....it is either solid or liquid and no in between.  For the cables I build for the satelittes (center pin of SMA male connectors), I use KESTOR Sn62/Pb36/Ag02 which is only 2% silver and called silver bearing.  You can still buy it on  Amazon.  As for flux, I use Kester RMA186 liquid and contrary to Paul, it does not "make the solder melt"....it basically de-oxidizes and provides a path for the solder to flow.  The flux inside the solder melts at 347 F.....BEFORE the solder melts at 361 F thus making the path for flow.  Remember when we were kids and had the little round can of Kester flux that you would dip into?

  

FYI:  To solder the pin of an SMA connector I do NOT rely on the flux inside the solder....Prior to inserting the center conductor of the RG-316/DS (mil-spec double shield teflon)  I apply a "dropllet" of RMA186 on the 7 stranded wire tip and insert it into the pin.....next I apply another "droplet" into the inspection hole (not called a solder hole).  Then I put a droplet of silver bearing solder on the PIN TIP of my iron and apply it directly to the hole in the pin.....magnification is definitely needed.  The solder flows into the hole and I tell my students that if you don't see an outline of the inspection hole, then you used too much solder and the pin will not insert into the into the body of the SMA.  I can make 6 to 8 cables an hour and all are within 1 (ONE!!!) MM tolerance in lengths.  If they want a cable 138 mm long from connector front to front, then it can't be 137 or 139 mm.....yep I can do that and I would love to show you all sometime.  And yes I crimp the ferrule.  I have 8 birds in space and the last three have 80 cables each of mine made in my basement.  

I am just waiting for the day when some USG safety officer comes into my class and has me surrender all "lead solder" and have to replace it with SAC305.  See my handouts below from my lesson plan.  Let me demo this for you all sometime.  It is said that I can put a Type-N male connector on a garden hose......HI HI.

  

Thanks for the link and remember.....The US is one of the few countries still using lead.  Hoard your lead solder.....the day is coming.

73 de Ron, WA6YOU

Solder and flux in use at N2CQR

By Jeff Murray K1NSS (2014)

Jam on Radar Antenna of Jupiter-bound Spacecraft FIXED! Antenna deployed!

Great news. This stuck antenna was getting me down.  Three cheers for the ESA folks who fixed it from afar.  

https://phys.org/news/2023-05-stuck-antenna-freed-jupiter-bound-spacecraft.html

Here is how they did it: 

https://www.esa.int/Science_Exploration/Space_Science/Juice/Juice_s_RIME_antenna_breaks_free

The RIME antenna looks a bit like one of my dipoles! But it can look 9 km into the ice. 

And what a great name:  Jupiter Icy Moon Explorer.  Juice. 

Godspeed JUICE!  

SolderSmoke Podcast #246: PeteGPT! DC RX, Si5351, Franklin osc, Cuban DSB, Hex beams, uBITX mods, DX, 10 meters, MAILBAG

 

SolderSmoke Podcast #246 is available: 

AUDIO PODCAST: http://soldersmoke.com/soldersmoke246.mp3

YouTube VIDEO: (247) SolderSmoke Podcast #246: uBITX, Hex Beam, DX, High School DC RX, 10 meter SSB Rig, MAILBAG - YouTube

The AI Deep Fake Threat!  PeteGPT!

Hearing Aid info:  I can hear the cymbals in my audiogram adjusted Airpods.

Update on the TJ DC RX project – Several receivers working! https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Sunil’s company provides Nano/Si5351 combos.  With the KD8CEC software. Very cool.  http://amateurradiokits.in They have a new SSB dual band transceiver – the Airpal.

Mark AJ6CU helping me. Sent me Nanos with KD8CEC software. His uBITX Settings Editor seems very cool. https://github.com/AJ6CU/uBITX-Settings-Editor/releases/tag/V2-beta-1  Thanks Mark.  

Franklin Oscillators. 

Cuban Islander and Jaguey info.  Send more!

Fixing up uBITX 2   How Bill blew up TWO Raduino Nanos. My results with the KB1GMX mods. (see below)

Hex Beam work:  Adding 10 and 15 meter elements.  But now I can hear AM breakthrough from WFAX 1220 AM  (5 kW during the day),  So I made a high pass filter.

Made first contacts on 15 and 10:  Argentina, Brazil, Dominican Republic.

First contacts with both India VU3TPW and China BA4TB.  SSB homebrew.

sBITX news. Taking orders!

Pete’s 10 Meter SSB Project

Mailbag:

--Wes W7ZOI provided great info and analysis on the Franklin oscillator. And lots of great tech info on other topics: http://w7zoi.net/oldtech/ponder.html Thanks Wes!
--Lex PH2LB. uBITX mods. TO-18 Heatsinks. New stickers (see above).
--Kostos SV3ORA and Hans G0UPL about the Franklin Oscillator.
--Listening to HRWB 178: Great stuff, many old friends: George KJ6VU moved to Oregon. Thomas K4SWL on the show.  Ben, an old friend of Pete’s,  mentions John Zaruba K2ZA – the guy who gave me the DX-100. Wonderful connections.
--Thanks to Todd VE7BPO for sending me another AADE LC meter. I need it for the SSSS.
--Nick MONTV planning a 15/10 meter dualband SSB rig. Me too! See video.
--Trevor Woods in W. Australia – The portrait in Artie Moore’s shack. Chuck WB9KZY – Willam Ramsay
--LA6NCA Helge three tube RX. Regen or DC? Mike Masterson WN2A and I discuss.
--Mike WU2D video on Retro QRP rigs – Steve G0FUW discusses Severn rig long in the works –started 1983 and nearly finished!
--Tim Hunkin of Secret Life fame did video with speaker made from potato ship bag. Discussed with Tony G4WIF and others. Also, Tim has an amazing video on cutting holes in metal. On the SolderSmoke blog.
--Bob Crane W8SX will be covering FDIM for SolderSmoke!
--Glen VE3DNL working on a more sophisticated DC RX.
--Craig KC2LFI from the beach on Grand Cayman. FB.
--Steve EI5DD reports We have changed our name - The May Issue of the HAM RADIO IRELAND Magazine, Ireland’s only independent magazine for the Radio Experimenter: https://docdro.id/SHH0VEy
--Mike EI0CL on 15 meters with Dean KK4DAS. FB
--Howard N3FEL of the Penn Wireless Association wants to do a group build of a DC RX.
--Martin LW9DTR in Buenos Aires looking for help with the code for an AD9850
--Todd K7TFC – always helping other homebrewers.
--Really thoughtful message from Kevin WN7Z

uBITX 2

My KB1GMX mods to uBITX 2

Boom! Small Electrolytics Blow-up in a Big Way. MAGIC SMOKE RELEASED!

It doesn't take much.  Like if you put 12 volts across a little electrolytic rated at 10 volts, WATCH OUT! The tranquility of your workshop could soon be very suddenly disturbed.  Even with the proper polarity, they will BLOW-UP.  The MAGIC SMOKE will be EXPLOSIVELY RELEASED. BOOM! 

And speaking of capacitors, Rogier PA1ZZ sends this: 

https://jupitercondenser.com/collections/audio-capacitors

But don't blow these ones up.  Some of them are 75 dollars a pop!  

Apex Surplus in Los Angeles

The Polaroid camera for the Tek 'scope was pretty cool.  And the comments about the Simpson 260 made me feel good about finding one at a recent hamfest, but I don't think mine is an extremely rare Model 2.   

Radio's Noble Savage: Jean Shepherd and The Secret People (that's us) -- Shep and Kludge?

I was looking at the pictures from the Nearfest hamfest when I spotted this quite from Shepherd at the bottom of a post in the AM Window by Carl WA1KPD: 

"Okay, gang are you ready to play radio? Are you ready to shuffle off the mortal coil of mediocrity? I am if you are." Shepherd

I Googled the quote and that took me to this 1966 article from Harper's: 

 http://www.keyflux.com/shep/shepharp.htm

The article is a (mostly) accurate view of Shepherd.  Much of it would not be socially acceptable today (and rightly so).  The article correctly describes Shep's stories as being truth-based but also filled with hyperbole.  

This got me wondering:  How did Shep pronounce kludge?  I mean, it could have been him who put me on the pronunciation track of kludge like fudge.  He wasn't being listened to outside of NYC, and maybe Boston and San Francisco.  So that may explain why the rest of the country is getting the pronunciation so completely wrong.  We may be on the verge of a breakthrough here.  Steve Silverman:  ALERT!  

Can anyone find a recording of Shepherd using the word Kludge? A Bronze Figlagee with Oak Leaf Palms will be awarded. 

Check out the Harper's article and the video (above) of Shep talking about THE SECRET PEOPLE.  

EXCELSIOR! 

Who is the Man in the Portrait in Artie Moore's Shack?

 

Who is this person?   He is in a prominent position in Artie Moore's very early radio shack.  Artie was obviously big on labeling things, and there is a label under the picture but I can't make it out.  What do you folks think?  Who is this?  

https://soldersmoke.blogspot.com/2023/04/artie-moore-and-titanic.html

High-School Students Successfully Avoid THE SHELF OF SHAME -- Update on the Direct Conversion Receiver Project

One of the first finished receivers

Dean KK4DAS, Mike KD4MM, and I had a good day at the local high school yesterday, even after a month of spring break and other absences.  We thought this might have been our last session at the school this year, so we strongly encouraged the students to GET THE RECEIVERS DONE.  We told them about the Shelf of Shame, and warned them not to half-way finish something that would gather dust at the bottom their parents' closet.  They were close to success!  It was time to finish the project. 

We warned them not to be perturbed if the receiver doesn't work the first time they power it up.  This is not "plug and play."  The receiver would likely need some trouble shooting, or at least some peaking and tweaking.  We noted that we often have to sort of coax a signal out of a newly built receiver. 

We soon had the students come forward with two projects that were ready for final testing.  Sure enough we found problems with both.  The solutions provided a lot of educational fun. 

The first group had not yet built the diplexer -- we advised them to skip over the diplexer for the moment -- just connect the output of the mixer to the input of the AF amplifier.  We can't let the perfect be the enemy of the good!  Build the diplexer later, but for now, get the receiver going.  They did, and a few minutes later they were receiving signals from Mike KD4MM's transmitter (on the other side of the lab). 

Then a second group came forward.  We put a San Jian frequency counter on the PTO output.  Uh oh.  Trouble.  Gibberish!  A wonderful troubleshooting session ensued.  With the student, we found that the signal was good at the output of the oscillator transistor, but NOT at the output of the buffer.  At first we suspected that the buffer was bad, but it was not.  Then we lifted the connection to the mixer and suddenly the buffer output was good.  So the problem was in the mixer!  When we disconnected the input transformer of the mixer from the diode ring, THE PROBLEM WAS STILL THERE.  So the problem was clearly in the input transformer.  Dean gave us a replacement transformer.  Soon all was right with the rig, and this group joined the ranks of the successfully completed receivers.   

I think that seeing that two groups had finished helped motivate the others.  Our announcement that successful completion would lead to a "Certificate of Completion" also helped.  But most of all, I think the natural desire to finish the job and avoid the "Shelf of Shame"  was pushing the students forward. 

Other news: 

-- Our stage-by-stage award program continued.  Last time we awarded "The Torry"  for the first successful bandpass filter;  this time we awarded "The Audy" for the first successful audio transformers. 

The Audies

-- We told the students that their work has been entered in a Hack-A-Day contest.  Most of the info and files on the project can be found on the Hack-A-Day site.  Check it out:  

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

-- We also told the students about Walter KA4KXX's very generous offer of a reward for the first students to check into the Florida Sunrise net.  (We had to make it clear that this offer is completely extracurricular and unconnected in any way from the school .)  The students were clearly intrigued.  Sunrise Net may get some new check-ins! 

-- We provided instructions on how to build a simple 1/4 wave reception antenna.  We also did a video.  

We had thought that this would be our last session at the school,  but at the students' request we will be back with them next week for another session.  We think there are at least five more receivers approaching the finish line. 

Retro QRP Rigs of the 1960's, 70's, and 80's -- Video by Mike WU2D

It is time to put aside (again!) all of the heated ideological arguments about the power level that defines "low power."  Just sit back and enjoy this wonderful trip down QRP memory lane. 

Mike's description of the simple, single-transistor QRP transmitter was really nice.   I recently made something similar: https://soldersmoke.blogspot.com/2023/02/first-qso-with-high-school-receiver-100.html  And Mike does a nice plug for our beloved Michigan Mighty Mite.  Go CBLA! 

The modular idea:  words to live by my friends. 

40673!  TT2!  And G3RJV's PW Severn - indeed, bow your heads!

Wow, the Ten Tec Power Mite (or Might!) -- I still want one.  Same for the Argonaut -- what a great name (sounds like a "magic carpet), and with SSB to boot!  I want to join the Argonaut cult! 

I have both the HW-7 and HW-8 (the HW-8 is heading to the Dominican Republic).  This video makes me want to fire up the HW-7.  Maybe on 40.  

My 40 meter homebrew rig (Digi-Tia) has in it the filter from that old Yaesu FT-7 rig.  The filter was given to me by Steve "Snort Rosin" Smith.  https://soldersmoke.blogspot.com/2015/05/bitx-digi-tia-build-update-2-installing.html  

Thanks to Mike for including me in the credit roll at the end.  What a great group of people -- it is a real honor to be listed with those folks. 

Tim Hunkin on Drilling Holes (Secret Life of Components Video)

 I guess that aside from being a great video, this is something of a test of technical nerdy-ism.  If you find this hour long video really interesting, well, you know... 

Really cool stuff from Tim Hunkin: 

-- I liked the angle driller.  Need one. 

-- The placement of the magnets near the hole to catch the shavings was really cool. 

-- Tim's reluctant admission that it is just better to buy new drill bits (as opposed to sharpening old ones) is good advice. 

-- WD-40!  Yea! 

-- Note:  No white "Boffin" coat for Tim.  Just "overalls."  But as I watched I found myself thinking that he could probably have used an armor plate or at least a Kevlar vest amidst all that flying metal. Perhaps a bit more eye protection too...  

-- Fiddley.  A useful tech term.  

--Swarf:  Another useful tech term:  the metallic remnants (shavings) of drilling. 

-- The digi readout on the milling machine looked really useful. 

Finally, I loved the sign that Tim has posted in his workshop:  

SMALL HADRON COLLIDER

Four Old BBC Shows on Radio: Hams, Physics, and Antique Wireless

The first one, about ham operators in general, is pretty depressing. Then it goes downhill as they shift to those who are listening to baby monitors and cell phones.  Yuck. 

The second one seems to show some physicist having understandable difficulty explaining particle-wave duality in a short TV segment.  

There is a short bit (that I didn't quite get) about the BBC's "Teddy Bear's Picnic."  

The final one is about Gerald Wells and his Antique Wireless Museum in South London.  Note the white coat -- clearly a boffin.  For a while I confused him with Rupert Goodwins G6HVY (similar white coat, but a different bloke).  

Helge LA6NCA's Altoids Tin Receiver

Here's another great video from Helge LA6NCA.  This is a follow-up to his Altoids Spy Transmitter project.   Really well done.   Hack-A-Day called this receiver "regenerative" so naturally I was disappointed, but when I watched I realized that it is NOT a regen but is instead a direct conversion receiver.  TRGHS.  All is right with the world.  Thanks Helge!  73 

Artie Moore and the Titanic

I had never heard of Artie Moore, but his is a very interesting story from the earliest days of radio. 

 https://en.wikipedia.org/wiki/Artie_Moore

https://www.facebook.com/groups/118053768802799

A Request for Digital Help from a Ham in Argentina

Can someone out there help OM Martin LW9DTR? 

His e-mail is on his QRZ.com page: https://www.qrz.com/db/LW9DTR

MARTIN LW9DTR has left a new comment on your post " The JF3HZB Digital VFO Dial in the DJ7OO Direct Conversion Receiver (Who is JF3HZB?) ":

Technical support
Dear Klaus Kirschelmann
My name is Martin and my call sign is LW9DTR
I am writing to you from my hometown of Buenos Aires, Argentina.
I need your tech support because I'm trying to run the assembly you posted with the AD9850 + Arduino Mini + Oled to apply it in a QRP transceiver project and I've encountered two problems.
The first problem is that I can't find the code to program the Arduino on your website.
The second issue is that the QRP transceiver design I'm using requires an inverted DDS output, ie as the frequency on the display increases, the output frequency should decrease.
I lack programming skills, so I'm coming to you knowing you can guide me on what commands I can change in the program to make this happen.
I will be very grateful to you in advance for your tremendous support.
I say goodbye with all due respect and wish that this April 18th, International Amateur Radio Day, surprises you with joy and new projects.
A big and warm hug.
With respect:
Martin Silva, LW9DTR

CuriousMarc Powers up (and Explains) Old Cathode Ray Tubes

Wow, really cool video from CuriousMarc and the guy who wrote the "Open Circuits" book.  But fellows, you really need to be more careful with the high voltage. Remember poor Ross Hull.  One hand behind the back would help.  Volts jolt, but mills kill.    

Inside "Open Circuits"

Here is a cool video about a very cool book.  I wasn't going to buy it, but when I saw it in a book store, I opened it up to a random page and found myself looking at the 2N3904. TRGHS.  So I bought it. 

https://soldersmoke.blogspot.com/2022/09/open-circuits-cutting-open-components.html

https://soldersmoke.blogspot.com/2023/01/open-circuits-inner-beauty-of.html

The Franklin Oscillator: A Super-Stable VFO. Why No Attention? Why So Little Use?

My Franklin VFO

Lee KD4RE of the Vienna Wireless Society has been talking about the Franklin oscillator. He has been telling us that it is very stable, and capable of stable operation up through the ten meter band.  Lee wants to build an direct conversion receiver for all of the HF bands with one of these circuits. 

I was skeptical.  First, I'd never heard of this circuit.  I'd grown up in ham radio on a steady diet of Hartley and Colpitts and Pierce.  Vackar or Clapp were about as exotic as I got.  And second, I'd come to accept that it is just not possible to build a good, stable, simple,  analog VFO for frequencies above around 10 MHz.  For example,  in his Design Notebook, Doug DeMaw wrote, "VFOs that operate on fundamental frequencies above, say, 10 MHz are generally impractical for use in communications circuits that have receivers with narrow filters."  DeMaw was known for resorting to variable crystal oscillators. 

But then this month Mike Murphy WU2D put out two videos about his use of the Franklin oscillator circuit in a direct conversion receiver at 21 MHz.   The VFO was shockingly stable.  I began to believe Lee.   I fired up my soldering iron and built one.  

WU2D's Franklin Oscillator

Lee was right,  it is in fact remarkably stable, even at higher frequencies. My build (see picture above) was a bit slap-dash and could be improved a bit, but even in these circumstances here is what I got.   This was with a stable 6 Volt Supply and with only a cardboard box covering the circuit: 

Local time                  Frequency

0543                           19.1114 MHz  (cold start)

0636                           19.1116 

0804                           19.1117

1034                           19.1118

1144                           19.1117

I started digging around for references to the Franklin.  There was nothing about it in Solid State Design for the Radio Amateur, nor in Experimental Methods of RF Design.  Pat Hawker G3VA (SK) did discuss it in his Technical Topics column in RADCOM, February 1990.  Pat gave a great bio on Charles S. Franklin (born in 1879 and a colleague of Guillermo Marconi). But tellingly, Pat writes that, "Despite its many advantages, the Franklin oscillator remains virtually unknown to the bulk of American amateurs."  

QST "How's DX" August 1947

It wasn't always unknown.   In the 1940s, we see articles about the Franklin oscillator circuit. There is a good one in the January 1940 issue of "Radio."  The author W6CEM notes that the circuit "is probably familiar to only a few amateurs."  It shows up in the "How's DX" column (above). And the 1958/1959 issue of Don Stoner's New Sideband Handbook we see a lengthy description of the Franklin oscillator.  Stoner wrote: "The author's favorite oscillator is the 'old time' Franklin, and it is believed to be the most stable of them all! This rock-solid device can put a quartz crystal to shame! Because it represents the ultimate in stability, it is the ideal VFO for sideband applications."  And we see a PTO-tuned Franklin oscillator in the July 1964 QST. And it is in the fifth edition of the RSGB Handbook (1976). 

Here is the January 1940 "Radio" with the Franklin oscillator article on page 41 by W6CEM: 

https://worldradiohistory.com/Archive-Radio/40s/Radio-1940-01.pdf

Here is the July 1964 QST article: 

http://jlandrigan.com/files/PTO%20VFO/PDF%20PTO%20VFO%20Horn%20QST%20July%201964.pdf

There was an article about the Franklin oscillator in 73 magazine by W4LJC in February 1999: 

https://worldradiohistory.com/Archive-DX/73-magazine/73-magazine-1999/73-magazine-02-february-1999.pdf   

The author notes that: 

Much more recently (2022), Mike WN2A, modified his Mousefet transmitters (seen in QRP Classics in 1992) to include the use of the Franklin VFO circuit.  Mike's documentation is really excellent.  Kostas SV3ORA has a Franklin oscillator in his Super VFO circuit.  Hans G0UPL has one on his site. 

Look, there may be reasons why the Franklin oscillator has been ignored.  But the circuit sure seems to present a lot of advantages.  Stable operation beyond the 10 MHz barrier is the big one.  Simplicity is another.  If there are problems and shortcomings, let's hear about them. But it seems as if the Franklin oscillator may provide the opportunity for us to build stable VFOs beyond 10 MHz without resort to complicated PLL stabilization techniques, and without opting to go with an Si5351 or other complex digital devices.   

So let me ask:  Why hasn't the Franklin oscillator been given more attention, and why haven't we seen more use of this circuit by hams or even by manufacturers?  

Farhan's sBITX -- Taking Orders! (Video)

It is really looking great.  Congratulations to Farhan for bringing yet another amazing rig to the amateur radio community.   

Order yours here: 

https://www.hfsignals.com/