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Tuesday, April 13, 2021

For Your Vacuum Tubes: Isotopic Ionization Sources from U.S. Radium

One or two podcasts ago I mentioned radium in regulator tubes.  As I predicted, this provoked a number of comments about how silly it is to even mention such things. Nonetheless, I find it interesting.  It seems that real radios really do glow in the dark!   

More info on the company: 

Sunday, April 11, 2021

RIP Isamu Akasaki -- Shared Nobel Prize for LED -- Analog Guy

From the obituary in the Washington Post: 

In addition to the Nobel Prize, Dr. Akasaki’s honors included a 2009 Kyoto Prize — Japan’s highest honor — recognizing developments in advanced technology. He found that some technology, however, needed no advancing at all. He took great pleasure, for example, in long-playing classical music records.

On that point, he joked, “I am analog.”

Thursday, April 8, 2021

N6QW On 40 Meters with a Civil Air Patrol Dentron Scout -- WYKSYCDS


Pete is in the air with his Dentron Scout.   Check it out: 

WYKSYCDS = When You Know Stuff You Can Do Stuff.  Pete proves it.  

Wednesday, April 7, 2021

"The Perfect Trap for the Engineering Mind" -- Leo Fernekes' Stirling Engine

I did a post about Leo back in August: 

Although it is not about radio, homebrewers will find much to resonate with in Leo's Stirling engine project.  

Warning:  There is a Part II.  And there may be more.  Proceed at your own risk. 

Sunday, April 4, 2021

A Satellite Ground Station (Receiver) Made from Junk

Very cool.  This guy (who brew up on an island in Alaska) really knows how to use aluminum tape and the junk that fills most workshops. I like his use of the security camera mount as an az-el antenna rotator. 

I foolishly discarded a Direct TV dish.  I could have been receiving GOES images by now! 

Just last week I got the same RTL-SDR.com V3 dongle that he is using.  Very FB.   It does HF direct sampling with no hardware mods and no upconverter. 

More from the builder, Gabe Emerson (KL1FI): 

Saturday, April 3, 2021

A VERY Successful April Fools' Day

I was worried.  It was early on the morning of April 1, 2021, and I had NOTHING. Maybe this  was because so much unbelievable stuff has recently happened in the world.  Or maybe it is because technology has been moving so fast that today's April Fools' joke is tomorrow's new device. Whatever the reason, for the first time in about 15 years, I had noting.  April Fools' Day has long been part of ham radio's culture and I was worried that I would not be making a contribution this year. 

Then something caught my eye.  Did you know that on Thursday they decided to change the rules of chess!  Yes indeed!  NO MORE DRAWS!   Fantastic!    This provided the inspiration for our announcement of the brutal FCC rule-making action regarding the banning of "legacy equipment."  

I knew that that headline would attract a lot of attention. And let me inform you that, according to the official rules of April Fools' Day,  if that headline did pull you in,  well that constitutes a "gotcha."  So far 1,758 people are in this category.  I thank you all.   

The comments attached to the announcement were really heart warming, even those that included profanity directed at my persona.  People recalled earlier April 1 events, like the time Pete was defenestrated from the QRP Hall of Fame.  Good times, my friends, good times!   

This was an especially happy April 1 for me, because I also launched two other highly successful operations: 

-- I teach a Zoom class.  On Thursday morning I told the students about new concerns regarding  the light hitting their eyes from the computer screens.  We were all being issued dark glasses and would henceforth have to Zoom with shades on (see above).  The students -- bless their hearts -- all agreed to do this.  

-- We are closely associated with a small company that has the word "native" in the corporate name.  As in "Native Vegetation."  Shockingly, last Thursday we got an e-mail from the Virginia Small Business Commission DEMANDING that we change the name of the company.  It seems that ANY use of the word "native" was now deemed unacceptable.  The people in this company (ALL OF THEM!) were really outraged by this.  I had to pull the plug before any legal actions were initiated!  

So, to all of you, Happy April Fools' Day!     

Thursday, April 1, 2021

FCC to Ban "Legacy" Equipment and Circuitry

From the FCC Newsline: 

Out with the old

In a long-expected policy move, the Federal Communications Commission today announced that starting on April 2, 2022,  all equipment in use by the amateur radio service must comply with strict emission purity standards.  The Commission's rule-making focuses on the bandwidth of high frequency transceivers.   Starting one year from tomorrow,  amateur equipment will be limited to a bandwidth of 3500 cycles per second.   Emissions outside the bandwidth limits must be at least 100 db below the average power in the bandpass.  In effect, this means that amateur equipment must make use of the kind of "brick wall"  filtering only available from software defined equipment.   Bringing the service into conformity with commercial practices, all high frequency equipment will be on Upper Sideband.  

"No more skirts" 

An FCC official -- who requested anonymity because of "threats"  -- told Newsline that part of the motivation behind today's announcement was a desire to end the unseemly discussion of the filter "skirts" of "legacy" ham radio gear:  "Obviously there were concerns about the pejorative way many hams were referring to 'the skirts.'  This is the 21st century!  It was time to be more inclusive!" 

Audio Tinkering to Continue

The FCC official told Newsline that the Commission is not in any way attempting to discourage hams from tinkering with the "audio quality" of their commercial SDR equipment: "As long as they keep the bandwidth to 3500 Hz, they can tinker and adjust to their hearts' content," said the official.  He went on to use some of the colorful language recently heard on the ham bands: "If they want to include very low audio frequencies -- what some call 'the thunder down under' they can do that.  Or if they want to emphasize the high frequencies -- for that "Krispy Kreme" sound -- they can do that too.   All they have to do is learn how to set  the menus on their equipment. We understand that the manufacturers will soon be making available software packages that will -- with just a simple download -- set the menus according to the desires of the consumer. Uh,  I mean of the radio amateur." 

The FCC official said he thinks the ruling will actually encourage and facilitate audio tweaking. "We know this is important to modern hams.  It makes them feel connected to the days when hams actually built their own equipment.  We have noticed the development of an amazingly rich  technical vocabulary, terms like 'presence'  "muddy'  'bright'  and 'punchy' are now in common use.  Clearly the Commission would not want to stand in the way of this kind of technical advancement!"

Sinking the Boatanchors

The FCC acknowledged that this ruling spells the end for on-the-air use of  older ham equipment. "Clearly none of that old junk will meet the new requirements.  I mean these guys were literally using hunks of rock to filter their sidebands.  It was practically medieval!  Time to wake up, smell the decaffeinated coffee, and get with the SDR program OM!" 

Fears of violent push-back

The FCC official did acknowledge that there are fears of possible violent push-back from certain "sub-cultures" in the ham radio world.  "Working closely with our partners in Homeland Security, we have looked closely at the possibility of violent pushback.  Of particular concern are groups that appear to be fiercely loyal to what they sometimes defiantly refer to as 'Hardware Defined Radio.'   There are some truly frightening groups out there.  One group is called the CBLA -- The Color Burst Liberation Army.   They seem especially fond of quartz crystals and are radically opposed to the new SDR requirements.  Also of concern are groups that continue to insist on using Double Sideband Unsuppressed Phone generated by equipment using vacuum tube.  Vacuum tubes! They call them 'thermatrons.'  Again this is really medieval."  The spokesman said that the FBI is monitoring these groups, but is not very concerned because of the physical condition of many of the fanatics.  "Most of these guys rarely leave their homes.  In fact, for the last year many of them seem to have been repeating a strange "Stay in the Shack" mantra.  Many still smoke, never exercise, and now refuse to take the vaccine.  So we are not too worried, " said the FBI spokesman. 

Support from Industry and the Major Ham Organization

FCC officials tell Newsline that the major equipment manufacturers -- along with the principal ham radio organization -- were very supportive of this move, seeing it as a major opportunity to "stimulate" both sales and advertising revenue. 

Wednesday, March 31, 2021

Mending vs. Ending -- The Fight Against Planned Obsolescence

We don't get a lot of mail from Darwin, Australia, so the message coming in from Phil VK8MC immediately got our attention.  When I looked into the details I realized that it was very SolderSmoke-relevant.  The Guardian article that Phil cited even mentions hobbyists tinkering with electronic devices in their sheds (that would be us!).    Phil points to the connection between our repair efforts and the struggle to save the planet: "It's not just a hobby, it's an ethical position which contributes to the well being of the planet. A higher calling indeed!" 

Here is the article Phil pointed us to:


The poster above (which hangs above my workbench) is from https://www.ifixit.com/Manifesto

Monday, March 29, 2021

"Analog Man in a Digital World" by OM Joe Walsh (music video)

After seeing my last post about SDR, the dongle, the Android tablet, and the Bluetooth mouse, Bob Keller grew concerned about my, uh, stability.  Here is our e-mail exchange. 


Have you had a comprehensive medical evaluation recently? All this digital activity from an erstwhile analog man is a concerning symptom. <g>

I suggest listening to the following number at least once each day until you have the chance to get checked out:

-- 73 de KY3R, 
    Bob Keller


I know.  It really is quite disturbing.  I've been getting a lot of "welcome to the dark side" messages!!!  

I am now trying to get back in the good graces of The Radio Gods.   Today I fired up the Fish Soup 10 and made two CW SKCC contacts on 40 meters.  I feel better already.  

Thanks for the song from OM Walsh.  I had heard it before but it is more meaningful to me now.  I will put it on the blog.  Others may need help too.  

Thanks for caring Bob.  



Tuesday, March 23, 2021

Double Sideband Transmitter using Vacuum Tubes -- From Sweden

Tommy SA2CLC has built a really nice DSB transmitter using Thermatrons.  
FB Tommy.  

Monday, March 22, 2021

My Hodgepodged Morse: Audio Tone into the Mic Jack Creates J2A not A1A. BASTA!

In SolderSmoke podcast #229 Pete and I were discussing my rather flaky effort to turn the Hodgepodge BITX40 Module into a CW rig by injecting keyed 700 Hz audio into the mic jack (see video below). We got some very helpful responses from ND6T and VK2EMU:  

Hi Bill,

You mentioned generating CW by modulating SSB: Collins did that in their
first SSB transceivers, I believe, as did SGC, but the results were less
than optimal. The problem is that you are involving the audio chain and
modulator. You know from experience how difficult it is to maintain low
intermod there and the tone is no exception. So we end up with lots of
spurs within the filter passband and then also have the opposite
sideband suppression less than perfect. If you check your transmitted
signal with a spectrum analyzer or SDR you can easily see the nasties.
Listening to a CW signal thus generated makes it obvious unless it is
buried way down in the noise. It IS a valid CW signal (not MCW) since it
is (almost) a single signal. However, in actual operation it doesn't
work very well.

I know because I have done that. I bought one of Farhan's original
BITX40 boards and wanted to put it on CW. I ended up injecting a keyed
signal from one of the spare clocks on the Si5351 into the RF amplifier
chain (thus avoiding the above stated problems) but still had garbage
from the audio and IF stages. I fixed that by shorting out that signal
during transmit by a transistor to ground. That was documented on your
BITXhacks website: http://bitxhacks.blogspot.com/2017/02/ and on my
website: http://www.nd6t.com/bitx/CW.htm . It has been a while, eh?


Don, ND6T


Hi Bill and Pete,

With putting an audio oscillator into you hodgepodge radio, your transmission is not the same as a standard CW rig.

If we have a transmitter as described in the ARRL handbooks from the 1940's or 1950's, (or even the Michigan Mighty Mite) it is a crystal oscillator and maybe a PA tube. By keying either the oscillator and/or the final PA on and off, then we can send Morse code as ICW Interrupted Continues Wave. If we check the list of emission designators, we have A1A.

However, if we feed a tone into a SSB transmitter, then we have J2A.

At the other end it may sound the same, but because it is created in a different way, it has a different designation. 

A quick look at Part 97 shows that J2A and J2B are classed as CW, so you are in the clear. However, if you put a tone oscillator into an AM signal to send CW, then that would be classed as A2A and not classed as CW, but as MCW. MCW can be used on 6 meters and above, but not HF.


73 de Peter VK2EMU


So I say BASTA with the J2A!  If I want to go CW, it's all A1A for me.  I dusted off my Fish Soup 10 and am now back on 40 CW with 200 mW.... A1A all the way! 


Saturday, March 20, 2021

SolderSmoke Podcast #229 -- G2NJ Trophy, SDR, HDR, CW! Mailbag

Soldersmoke Podcast #229 is available: 


--  G2NJ Trophy is awarded to Pete Juliano, N6QW. 

 -- Get your vaccine shot as soon as you can!  

-- More from "Conquering the Electron" by Derek Cheung. 

-- Bad fire in the chip factory.  Such a shame.  Sad!  I had NOTHING to do with it.  I was home that day.  I can prove it.

 -- Bezos is not such a bad guy.  Turns out he is a space-geek.  

 -- Perseverance was the big space news.  Very cool.  


Pete's bench:

Raspberry Pi vs. Microcontrollers

Treedix display

Conversion of the Dentron Scout

CW rigs?

6L6 on a wooden chassis




--  Our Patreon sponsors get an early look at our YouTube content.  So please, consider

becoming a Patreon sponsor.

--  Please continue to use the Amazon search engine on the blog page (upper right).   

Bill's bench: 


-- BITX40 Module.  

-- Ramseykit Amp. 

-- San Jian counter,  

-- CW using 750 Hz oscillator. 

-- RF-actuated piezo buzzer.  

-- SDR!  SDR using PC and tablet.  

-- Checking the output with SDR.  

-- Moving the carrier osc frequency.  

 Also, I put the Fish Soup 10 back on the air.  Nice contacts under 200 mw.

Up next:  A rig for 80/75 and 20 meters.  Single Conversion.  Using VFO from a Yaesu FT101 that runs 8.7 – 9.2 Mhz.   Quiz question:  What IF should I use?


Mark Zelesky sent me wood tokens with power and Ohm's law formulae.  Thanks!

Scott WA9WFA Built a really nice Mate for Mighty Midget RX – getting it going!

Tryg EI7CLB found board of his George Dobbs Ladybird RX.  Rebuild it OM!

Tom WX2J – We talked about “No lids, no kids, no space cadets” nastiness.

Nick M0NTV about sideband inversion.  I like the simple rule about subtraction.

Jonathan M0JGH – Always listen to Pete.  Got married, has mixing product. Leo?

Mike AE0IH.  Dad used a BC-348 in the service. Looking for one.  FB.

Adam N0ZIB – “Silent Shep” site --- with some ham radio shows I had not seen.

Walter KA4KXX in Orlando has a similar subtraction problem with San Jian counter.

Bill N5ALO sent me a really nice KLH speaker.   I’m using it now.

Jason N2NLY – interested in building SSB transceiver.  One step at a time OM…

Trevor in Annapolis sent xcsd cartoon that really hit home. 

Farhan is doing OK in India, diligently protecting his family from the virus.  

Peter VK2EMU also doing well.

Dave AA7EE Casually killed a DC receiver in Hollywood, and disposed of the remains. 

Charlie ZL2CTM doing great things with simple SSB.  Blogpost.

Phil VK8MC in Darwin sends article on "Mend not End" battle against planned obsolescence.

Bob KY3R re my SDR adventures, asked if I’ve had a recent medical/psychiatric evaluation. 

Friday, March 19, 2021

Hodgepodge: Tablet SDR with a Bluetooth Mouse (video)

I continue to find things in the shack that I can connect to the Hodgepodge.  Here it's an old Android tablet with a Bluetooth mouse.   

The waterfall is pretty, but this addition just shows why SDR is really TOO easy.  The modified RTL-SDR dongle is doing direct sampling, so there is not even any phasing circuitry to tinker with.  All the filtering and sideband selection is happening in software inside the 40 buck Android tablet.  The results look nice, but I don't find it very satisfying -- all I did was connect some cables.  So it's back to HDR for me. 

Tuesday, March 16, 2021

A REALLY Cheap Receiving Rig

Wow, lots of ingenuity in this 1921 receiver.

-- Has anyone actually made a diode out of a light bulb in the way described? 

-- The antenna coupler on the table leg is not much different from the tuner that I have attached to the wall of my car port. 

-- Note that when our hero finishes the receiver, he is able to pick up signals from Mars!  FB OM. 

Who will be the first to recreate this 1921 receiver? 

Monday, March 15, 2021

Aladdin's Lamp == The Vacuum Tube (aka The Thermatron) (Video)

After our posting of the video about 1957 transistor production, our friend Peter O'Connell VK2EMU asked for some equal time for vacuum tubes.  He sent me this 1940 Western Electric video.  It is quite interesting. 

-- I like the Aladdin's lamp metaphor.  When I was out in the Azores I thought of my homebrew 17 meter DSB rig as my "magic carpet." 

-- Lowell Thomas was brought in to narrate.  His voice sounds a lot more natural than that used to narrate the transistor film. 

-- To explain the effectiveness of transcontinental telephony with vacuum tube repeaters, they compared the system that of a relay of "hog callers" claiming that it would take 100,000 hog callers to carry a signal from New York to San Francisco.  So perhaps this could be a rival to db?   100,000 hc? 

-- Arlington to Paris 1915 caught my eye -- Arlington Va. is right down the road. 

-- The film of Edison in his lab was good to see.  And note the importance of his lab notebooks. 

-- The explanation of thermionic emission was quite good.  But of course too much credit was given to Lee DeForest. 

-- The breathless description of the amazing uses of tube technology was for me a reminder of how recent this technology is.  My father started as New York City cop in the 1950s.  He always referred to his police car as a "radio car." 

Hey, are any radio amateurs out there using one of those big water-cooled tubes?  If not, why not? 

Sunday, March 14, 2021

A Homebrewer


That is Homer Price, the lead character in two books by Robert McCloskey, published in 1943 and 1951.  The thing in the valise is Homer's pet skunk.  Of course. 

More info here: 

Homer is clearly a fellow we need to know more about.  I have ordered the book. 

Saturday, March 13, 2021

Making Transistors in 1957

Thanks to Thomas K4SWL for alerting us to this video -- he had it on his excellent SWLing Post blog

Many things crossed my mind as I watched this video: 

-- Pocket protectors!  Pete recently noted that this was a common fashion accessory among electronic techs and engineers back in the day. 

-- HP test gear. 

-- "Extreme cleanliness" that doesn't seem quite so clean.  

-- 550 transistors per hour.  Now we have upwards of 50 billion on a single chip. 

-- The Germanium salami that Pete mentioned in our last podcast. 

-- Hints of Silicon's impending replacement of Germanium. 

-- A transistor factory in Spring City, Pa. that "hums with excitement" (seemed kind of sleepy). 

-- The 1957 assumption that Philco transistors would be in the first orbiting satellite.  Then came Sputnik.

-- The transistor that moves like a "Gulliver through Lilliputian lands."  

-- Our voices or accents seem to have changed, at least the voice used in products like this.  No one talks that way today. 

-- As I watched, I tried to remember if Pete's CK722 was made by these folks.   But no, that was a Raytheon product.   Here is a nice short description of the early days of the CK722:   https://en.wikipedia.org/wiki/CK722   We need to learn more about the hobbyist Carl Todd.

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