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Showing posts with label radio history. Show all posts
Showing posts with label radio history. Show all posts

Monday, December 1, 2025

Book Review: "Big Ear Two -- Listening for Other-Worlds" by John Kraus (1995)


This book is kind of weird, but give it a chance.  The author seems too prone to describe the physical attributes of his colleagues, especially female colleagues.  But he was born in 1910 -- he was an old guy when he wrote this book, so perhaps we should cut him some slack.   And there is one memorable episode where he defends a female applicant.  In spite of the shortcomings, there are many real gems in there, often hidden among the descriptions of 1930's era Kleenex machines and refrigerators.  I picked up the book a long time ago and only read it recently.   

Some highlights: 

-- Crystal Radios in the 1920s. 

--  Working Australia from Michigan on 40 CW in 1927. And waking up his parents to tell them. (Decades later, I did the same thing after a ZL contact).
 
-- Doing a radio propagation survey using the 5 meter band (FMLA!) 

-- Jansky's  discovery of an extraterrestrial hiss in 1932.  (It seems like that was the big discovery,  So why did Penzias get the Nobel prize?) 

-- A youthful trip to Nazi Germany and the Soviet Union. 

-- A regular ham band schedule from Ann Arbor to Berkeley that featured Ernest Lawrence and Robert Oppenheimer.
 
-- Lots of mention of Fred Terman,  Grote Reber, and Karl Jansky,
 
-- Some discussion of how Jansky was turned down for a job.  And about how being a radio amateur actually hurt chances for employment; there are a few lines about anti-ham prejudice. 

-- Lots of people known to us show up in the book:  Joe Taylor, Shoemaker and Levy of Shoemaker-Levy 9 fame, Arthur C. Clarke, Maarten Schmidt of "First Light," and many others.   

-- And of course, the WOW signal (that has recently been explained as probably having a natural origin).  

-- Kraus tells of how the Latin words "Ad Astra per Aspera" (to the stars, with difficulty) were engraved above their radio telescope receiving room.  He goes on to (correctly) criticize those who write about radio telescopes, without having ever built one.  Remarkinig on one such critic, John Bolton, a revered Austialian radio astronomer and radio telescope builder, wrote, "If the writer had built a radio telescope his story of radio astronomy would be a different story." 

Here is a good review of Kraus's "Big Ear Two" book: 

https://reeve.com/Documents/Book%20Reviews/Reeve_Book%20Review-Big%20Ear%20Two.pdf

Friday, November 14, 2025

Early SSB in India: Espionage, Stolen Secrets, and Kleptomania

 

Earlier this month I had stumbled across a 1964 QST article entitled "A Sideband Transceiver, VU2 Style."  I forwarded the link to Pete N6QW, Grayson KJ7UM, and to Farhan VU2ESE.  Last night Farhan sent me this insider look at early SSB in India.  It is really great.  The battle for preeminence among early SSB homebrewers in India reminds me a bit of Jean Shepherd's descriptions of homebrew radio in Hammond, Indiana.   Farhan's description of the early rigs being "all over the place, in about 3 or 4 boxes... with a whole lot of  wires running all over"  really resonated with me -- yes, even today, that is true homebrew. Thank you Farhan for sharing this with us. 

Farhan writes: 

VU2NR, Raju was a legend! Quirky, brilliant and liked to be by himself. He lived to a very old age of 100 or so. He was the first ham to get on SSB from India. Therein hangs a story of espionage, stolen secrets, cold war, politics and kleptomania. Most of the actors are now dead, so it can be told now.

I never met VU2NR, he rarely travelled. One evening at Paddy's shack, I was shooting the breeze with VU2RM, Ram, about my own SSB efforts. Ram was probably the most knowledgeable ham on SSB in India and his RM96 was widely duplicated. Paddy and Ram were trying to empty out a bottle of the Old Monk and I casually mentioned how we had to scrounge around for SSB lattice filters until Wes showed us how to build them ourselves. At that point, Ram unloaded this story to us:

VU2NR joined the Allies and worked as a radio mechanic with the RAF. After the war, he joined the ICAO (International Civil Aviation Organization) and then finally the United Nations as a comms expert, he was in Aden for a while. He understood the radios well and he became a well known homebrewer. His most brilliant work was the NR60 (it is an SSB radio built around four CA3028 kind of mixers). It was the first SSB radio that I had built (and it worked!) but we are getting ahead of ourselves.

Back in the 50s, ham shacks of India consisted of World War II surplus receivers and a self-built 807 transmitter driven by a VFO. There was a fair amount of buzz on the bands about SSB. The hams could occasionally pick up DX that was on SSB and easily resolved by the BC-348s  and the HROs but there was no way to build one. The QST was difficult to get your hands on but Raju had become a subscriber of the QST during his RAF days.

A QST sailed on a slow boat from the USA and landed up at the port on the east coast of India, Vizag and made its way to Raju's doorstep. Over weeks, he gathered parts and in the summer of 1955 he quietly came on 40 meters on SSB! This blew everyone away. Until now, one had only heard stories of SSB transmitters told by sailors of Sandra Maria Gracia after a few drinks to a bunch of hams clutching onto their 807s. It was as if Jesus had materialized!

VU2RM, Ram was not amused. He was a homebrewer with pride and honour. He could never be bested. He spent the next evening tuning on Raju's SSB up and down to note that the other sideband was missing and the carrier was gone. It sank into him that Raju had indeed beaten him to SSB. Ram worked at the Kakinada port, about 100 miles further down south on the east coast as the port radio engineer. He didn't sleep well. At 5 am, he got up, walked out and took a bus to Vizag where Raju lived. He was at Raju's door at 9 am. Raju was amused at the young guy and invited him in. They knew each other as rival homebrewers. There was tension in the air. Raju showed off his SSB transmitter in the front hall of his home. It was all over the place in about 3 or 4 boxes. There was the power supply, the PA, the ssb generator using a 2Q4 (a passive RC phasing network), a separate VFO box and a whole lot with wires running all over. In a corner was his stack of QSTs.

Raju's XYL called out for coffee and snacks (called 'Tiffin' in south Indian English) and Raju sauntered off to the kitchen to fetch his celebratory feast...

With alacrity and swiftness that only comes once in a lifetime, Ram, VU2RM, sprang to action. He darted to the QST collections, quickly found the one with the SSB transmitter on the cover, turned the pages to discover VU2NR's dog eared pages. He was staring at the circuit trying to memorize it. He realized that 2Q4's internal diagram had really odd values that he could never remember. So he did what James Bond, Bertie Wooster and Louvre thieves would have done. He rolled it up and slipped it into his pocket! (In those days, QST could be rolled and slipped into your trouser pockets, leading to wider dissemination of knowledge). He called out to Raju asking him to forget the refreshments as his bus was due back home. He legged it out and didn't stop until the bus stop. He hid around the bus yard hoping to not be caught by Raju. In the meantime, Raju, cursing the young upstart, drank both the filter coffee cups and left for work. Raju was unaware that the royal jewels were stolen.

VU2RM, Ram, started to work on his SSB radio over the next few days. He stopped going to work. At first, he figured out how to null the carrier using a twin triode modulator. Next, he fabricated the 2Q4 circuit. He sand papered lower value resistors until they read as close to the value as he could manage on his analog volt-ohm meter. He gave up on the exact capacitances and just soldered a bunch of the closest together. He had a crude 2Q4 equivalent. This, he dropped into his rat next circuit and an 'Almost' SSB signal emerged. He was probably having a sideband suppression of less than 15 dB at this point. It was suppressed and the carrier was nulled. He declared victory.

In the morning, Ram was on the band strutting off his SSB transmitter to the local gang. Graciously accepting the accolades from his fan club and extolling virtues of life on SSB to the lesser mortals. The news quickly spread over CW and AM of VU2RM as the second SSB station from India.

In the meantime, the atmosphere at VU2NR was tense. You could cut the air with a toggle switch. Raju had no idea how Ram had gotten the SSB. He carefully tuned around on his signal. He could pick up faint traces of the opposite sideband. Ram's carrier was also leaky. He decided that Ram was probably passing off his AM transmitter as a SSB. He said as much on air to his own devotees. Ram, ever watchful of his own reputation, heard this criticism and broke in, challenging Raju to prove that his was indeed not SSB. Raju's reaction was mixed. Now he wasn't sure. 

It was now Raju's turn to have a sleepless night. After his breakfast, he had had enough of confusion and he hauled his old scope and himself into the 8 am bus to Kakinada and showed up at Ram's doorstep! "Show me your radio" he said crisply.

For Ram it was his moment of crowning glory. He had brought Raju down to his shack! Raju plugged his scope into Ram's transmitter. He sniffed around the transmitter which was laid all over the table. "Where is your 2Q4?" he asked. Ram pointed to bunch of resistors and capacitors and Raju realized Ram's dog headed brilliance. He sat down, traced to the balancing pots (there would be two of them as this was a phasing transmitter). At this time, he decided to show Ram his greater prowess. He reached out to the carrier nulling pots, and tweaked them to minimum carrier (Ram was watching the oscilloscope with his mouth wide open). He told Ram that he had now fixed the carrier and then showed him how to adjust the RF phasing control for minimum by tuning to the opposite sideband on Ram's Bc 348. Having proved to Ram that he was a better homebrewer, he declared that now, Ram's transmitter was indeed SSB and not semi-AM. Raju retrieved his honor by being gracious and "mentoring" Ram.
 
They had coffee and snacks and it was time for Raju to leave, as Ram was showing Raju to the door, Raju's eye caught a QST on the shelf... he pulled it out and stared down at the QST with his own address neatly stickered on the QST's cover. He glared at Ram for a long time and turned away and left in a huff. Ram called after him down the street but Raju was gone.

VU2NR's last radio was built when he turned 90. It was the NR90 and it was built using NE612 chips. His hamming came to an abrupt end when one day his son dropped in unannounced only to find him perched on his tower of 30 feet height, fixing a fallen element of his self-made log periodic. The son was so horrified that he took away all the radios to save him from self-harm (this part of the story is unconfirmed).
 
My friend Sasi, VU2XZ, was close to him and he got the family to donate his callsign to a repeater that has been established in his memory. VU2NR lives on.
- f 

------------------------

Here is the link to the 1964 QST article.   VU2NR's article appears on page 19: 

Saturday, May 17, 2025

MIT's Haystack Observatory and Dr. Herb Weiss


We are really privileged to have among us (and in the SolderSmoke Direct Conversion Hall of Fame) Phil Erickson W1PJE.   Phil is the Director of the MIT Haystack Observatory. 

Phil writes: 


Hi Bill, Dean, and Pete,

  I surfed over today to Soldersmoke and noticed you had put up a very nice film from the 1960s made by MIT "Science Reporter" on the DSKY design for the Apollo Guidance Computer.

  In the same vein, you might enjoy viewing something from the same era on the Haystack 37m telescope / radar in its early mid 1960s days:

 
  The video features Dr. Herb Weiss who is still with us at nearly 106 years old (he visited a couple years ago).  


  Herb built the observatory for its original ballistic missile radar / satellite imaging mission and was involved in early MIT microwave radar development.  

"Growing up in Elizabeth, New Jersey, Herb liked gadgetry. As a teenager, he became a ham radio operator and built a primitive television set at the same time NBC was trying to get its first signal on the air. His shop teacher was so impressed by Herb’s genius that he contacted MIT, which invited Herb to attend the college.

He spent the bulk of his career developing radar when there was none in the United States. He joined the Radiation Lab at MIT, which was just being established to support the war effort during World War II, designing radars for ships and aircraft. In 1942, when England was in the throes of its air war with the Nazis, Herb went to England and installed radar in planes with a novel navigation system that he and a team had designed for the Royal Air Force. He later spent three years at the Los Alamos, New Mexico, laboratory improving instruments for the A-bomb. After seeing the need for a continental defense network against the Soviet missile threat, he returned to MIT to build it. If not for Herb, there also likely would be no MIT Haystack Observatory, a pioneering radio science and research facility."

  As you can see from above, Herb is also a ham:


"Weiss:

Okay. I was born in New Jersey, and my first acquaintance with electronics was about the age of 12 or 13. We had a battery-operated radio, which didn't work, and I asked around about what do we do about it. They referred me to a man two blocks away, who was a radio ham it turned out. So I carried this monster with the big horn and, I guess, the dog sitting on the speaker to his house. We went down in the basement, and I was just fascinated. I was hooked right then and there. A year later I became a radio ham at the age of 13, 14 and literally have been in the field ever since, until I retired. I was fortunate enough to go to MIT as an undergraduate, and most of the people I ran into of that vintage didn't really have a hands-on feeling for electronics. By the time I got to MIT, I had built all kinds of things, including a TV set. Then it turned out that NBC was just trying to get their TV set on the air in New York on top of the Empire State Building."

https://ethw.org/Oral-History:Herbert_Weiss

  Herb and his wife Ruth had another career after MIT as a wind power pioneer and he is still an avid sailor:


  One of our inspirations, and it came from building ham radio sets as a youngster.  Enjoy the history.

73
Phil W1PJE

--
----
Phil Erickson

phil.erickson@gmail.com 


-------------------------------------------------

I would really like to get more info on Herb's homebrew TV receiver.  His was significantly earlier than the one described by Jean Shepherd

Thanks Phil!  And thanks Herb! 

Tuesday, January 14, 2025

Shock and Awe: The Story of Electricity --- Wonderful Video by Jim Al-Khalili (sent to us by Ashish N6ASD)

From Ashish N6ASD -- Oil Lamps and Electronics

Here is the link to the video: 


First, thanks to Ashish Derhwagen N6ASD for alerting me to this video.  You should all check out his blog

This is a really important video.  It is the best I have seen about the history of electricity and electronics.  It is from 2011, but it is still very good. Jim Al-Khalili travels through the world and displays the actual devices developed by the likes of Heinrick Herz,  Guglielmo Marconi, and Jagadish Chandra Bose.  There is great discussion of Benjamin Franklin, Volta and Galvani.  The role of electricity in The Enlightment is discussed.
  

Jim talks about the early transatlantic cables, and why some of them didn't work. 

We see Jagadish Chandra Bose developing early point-contact semiconductors (because the iron filings of coherers tended to rust in the humid climate of Calcutta!) 

There is a video of Oliver Lodge making a speech.   There is a flip card video of William Crookes (one of the inventors of the cathode ray tube and the originator of the Crooke's cross).  

We see actual coherers.  

There is simply too much in this video for me to adequately summarize here.  Watch the series.  Watch it in chunks if you must.  But watch it.  It is really great.  

Thanks Ashish.  And thanks to Jim Al-Khalili.  

https://www.youtube.com/watch?v=Gtp51eZkwoI

Sunday, January 12, 2025

Some History of Homebrew Ham Radio -- From Wikipedia and from K0IYE

Frank Harris K0IYE's Homebrew Station

From Wikipedia:  https://en.wikipedia.org/wiki/Amateur_radio_homebrew 

In the early years of amateur radio, long before factory-built gear was easily available, hams built their own transmitting and receiving equipment, known as homebrewing.[2] In the 1930s, 40s, and 50s, hams handcrafted reasonable-quality vacuum tube-based transmitters and receivers which were often housed in their basements, and it was common for a well-built "homebrew rig" to cover all the high frequency bands (1.8 to 30 MHz). After WWII ended, surplus material (transmitters/receivers, etc.), was readily available, providing previously unavailable material at costs low enough for amateur experimental use.[3]

Homebrewing was often encouraged by amateur radio publications. In 1950, CQ Amateur Radio Magazine announced a ‘‘$1000 Cash Prize ‘Home Brew’ Contest’’ and called independently-built equipment ‘‘the type of gear which has helped to make amateur radio our greatest reservoir of technical proficiency.’’ The magazine tried to steer hams back into building by sponsoring such competitions and by publishing more construction plans, saying that homebrewing imparted a powerful technical mastery to hams. In 1958, a CQ editorial opined that if ham radio lost status as a technical activity, it might also lose the privilege of operating on the public airwaves, saying, ‘‘As our ranks of home constructors thin we also fall to a lower technical level as a group’’.[4]

In the 1950s and 60s, some hams turned to constructing their stations from kits sold by HeathkitEicoEF JohnsonAllied Radio's Knight-KitWorld Radio Laboratories and other suppliers.[5]

From "From Crystal Sets to Sideband" by Frank Harris K0IYE https://www.qsl.net/k0iye/

Dear Radio Amateur,

 I began writing this book when I realized that my homebuilt station seemed to be almost unique on the air. For me, the education and fun of building radios is one of the best parts of ham radio. It appeared to me that homebrewing was rapidly disappearing, so I wrote articles about it for my local radio club newsletter. My ham friends liked the articles, but they rarely built anything. I realized that most modern hams lack the basic skills and knowledge to build radios usable on the air today. My articles were too brief to help them, but perhaps a detailed guide might help revive homebuilding. I have tried to write the book that I wish had been available when I was a novice operator back in 1957. I knew that rejuvenating homebuilding was probably unrealistic, but I enjoy writing. This project has been satisfying and extremely educational for me. I hope you'll find the book useful...

...My personal definition of “homebuilding” is that I build my own equipment starting from simple components that (I hope) I understand. I try not to buy equipment or subassemblies specifically designed for amateur radio. I am proud to be the bane of most of the advertisers in ham radio magazines. I still buy individual electrical components, of course. I just pretend that the electronics industry never got around to inventing radio communications. 

An irony of our hobby is that, when the few remaining homebrewers retire from their day jobs, they often build and sell ham radio equipment. These industrious guys manufacture and sell every imaginable ham gizmo. I doubt any of them have noticed that, by making everything readily available, they have discouraged homebuilding.

Tuesday, October 8, 2024

The Transistor that Changed the World -- the MOSFET


Another great video from Asianometry.  

My only quibble is that it kind of left unclear the differences between JFETs and MOSFETs.  After all, we still use both.  Note our beloved J310 JFET.  And the IRF510 is a MOSFET.  

Google's AI explains: 

A JFET (Junction Field-Effect Transistor) and a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) are both types of field-effect transistors, but the key difference is that in a JFET, the channel conductivity is controlled by a reverse-biased PN junction, while in a MOSFET, it's controlled by an electric field across an insulating layer between the gate and the channel, allowing for a much higher input impedance and greater design flexibility in MOSFETs; essentially, MOSFETs are considered a more advanced version of JFETs with superior performance in many applications like high-speed switching and integration into complex circuits. 

Saturday, September 7, 2024

Sony and the Transistor


I found the comment about Sony's belief that NPN transistors are superior to PNP very interesting. 


Tuesday, August 20, 2024

"The Far Sound" -- Bell System Video from 1961 -- Good Radio History (video)


This is a really OLD video, but there is a lot of great material here: 

-- Tubes.  (Valves or Thermatrons)
-- Coax.  
-- Frequency Division Multiplexing. 
-- Negative Feedback and the fight against distortion. 
-- Transistors and early experiments with semiconductors.
-- Fiber optics and Masers.
-- Satellite communications.
-- Early hopes for video communications.

The video is, by today's standards, extremely misogynist.  And the sound experiment with the poor woman wearing a male head was just weird.   But still, an interesting film. 

Thanks to Mark KM4GML for reminding us of this wonderful Bell Labs (AT&T) video archive. 

 

Saturday, May 11, 2024

Jens OZ1GEO's AMAZING Radio Museum



Brace yourselves.  This is just too much, too much radio history, too much cool stuff.  We are into ham radio sensory overload territory here. The rigs, the radios, the radioactive stuff (including tubes!).  Lots of Whermact stuff.  A Chinese receiver.  Tesla coils and Faraday shields.  Much more. 

Thanks to Helge LA6NCA for alerting us to this and for shooting these videos.  And thanks to Jens OZ1GEO for putting this magnificent collection together.  I hope they find sometplace to keep this all together so that future generations can benefit from it. 

George WB5OYP points out there is more from Jens here: 

Thursday, March 7, 2024

The Wizard of Schenectady -- Charles Proteus Steinmetz

Such a beautiful article.   Ramakrishnan VU2JXN sent it to me.  It reminded me of how puzzeled we were when we found "Schenectady" on old shortwave receiver dials, amidst truly exotic locations.  Rangoon!  Peking!  Cape Town!  Schenectady?   Obviously this was due to General Electric's location in that New York State city.  But reading this article, I am thinking that the presence of Charles Proteus Steinmetz had something to do with it. His informal title (The Wizard of Schenectady)  confirmed that we have been right in awarding similar titles to impressive homebrewers. 

Here is the Smithsonian article that Ramakrishnan sent. 

https://www.smithsonianmag.com/history/charles-proteus-steinmetz-the-wizard-of-schenectady-51912022/#ixzz2lRMjrfit

And here is a link to a PBS video on Steinmetz: 

https://www.pbs.org/video/wmht-specials-divine-discontent-charles-proteus-steinmetz/

Here is a SolderSmoke blog post about "Radio Schenectady":

https://soldersmoke.blogspot.com/2020/07/radio-schenectady.html


Wednesday, March 6, 2024

N6ASD Builds a Zinc-Oxide Negative Resistance Transmitter (and a Spark/Coherer rig)


I saw this video and post on Hackaday this morning:


I got the fellow's callsign from  his Morse CQ.  
It is N6ASD in San Francisco. 

Check this out from his QRZ page: https://www.qrz.com/db/N6ASD

My journey into the world of amateur radio began in a very primitive way. My first "rig" comprised of a spark-gap transmitter and a coherer based receiver. A coherer is a primitive radio signal detector that consists of iron filings placed between two electrodes. It was popular in the early days of wireless telegraphy.

Spark transmitter (using a car's ignition coil to generate high-voltage sparks):

Coherer based receiver (using a doorbell for the "decoherer" mechanism):

When I keyed the transmitter, a high voltage arc would appear at the spark-gap and this produced (noisy) radio waves. The signal would be received by the iron-filings coherer on the other side of the room. A coherer is (usually) a one-shot receiver. You have to physically hit it to shake the filings and bring the detector back to its original state. That's what the doorbell hammer did. It would hit the coherer every time it received a signal. It amazed me to no end. A spark created in one room of my house could make the hammer move in another room. Magic!

Soon after this project, I started experimenting with *slightly more refined* crystal detectors and crystal radio circuits. As most of you would know, these amazing radios don't require any batteries and work by harnessing energy from radio waves. I guess these simple experiments instilled a sense of awe and wonder regarding electromagnetic waves, and eventually, this brought me into the world of amateur radio in 2015.

My main HF rig is an old ICOM IC-735. The only modification on this is radio is that it uses LED backlights (instead of bulbs):

Icom IC 735

With space at a premium in San Francisco, the antenna that I have settled for is an inverted vee installed in my backyard (and it just barely fits). I made the mast by lashing together wooden planks. For this city dweller, it works FB:

I have recently gotten into CW, and it has definitely become my mode of choice.

I'm a self-taught electronics enthusiast and I love homebrewing radio circuits. I'll be sharing more info about them soon.

Thanks for checking out my page. I hope to meet you on the air!

73,
N6ASD

 

Monday, February 19, 2024

Jean Shepherd has Trouble with his Heising Modulator (and his date)


This is probably Jean Shepherd's best program about homebrew ham radio.  It is about how we can become obsessed with the problems that arise with equipment that we have built ourselves, and how normal people cannot understand our obsessions.   

I posted about this back in 2008, but I was listening to it again today, and quickly realized that it is worth re-posting.   Realize that Shepherd's Heising modulation problems happened almost 90 years ago.  But the same kind of obsession affect the homebrewers of today.  

Note too how Shepherd talks about "Heising" in Heising modulation.  Heising has an entire circuit named for him, just like Hartley, Colpitts, and Pierce of oscillator fame.  Sometimes, when I tell another ham that my rig is homebrew, I get a kind of snide, snarky, loaded question:  "Well, did you DESIGN it yourself?"  This seems to be a way for appliance operators to deal with the fact that while they never build anything, someone else out there does melt solder.  They seem to think that the fact that you did not design the rig yourself makes your accomplishment less impressive, less threatening.  This week I responded to this question with Shepherd's observation -- I told the enquiring ham that my rig is in fact homebrewed, but that I had not invented the Colpitts oscillator, nor the common emitter amplifier, not the diode ring mixer, nor the low-pass filter.  But yes, the rig is homebrew, as was Shepherd's Heising modulator.    

Guys, stop what you are doing. Put down that soldering iron, or that cold Miller High Life ("the champagne of bottled beer") and click on the link below. You will be transported back to 1965 (and 1934!), and will hear master story-teller Jean Shepherd (K2ORS) describing his teenage case of The Knack. He discusses his efforts to build a Heising modulated transmitter for 160 meters. He had trouble getting it working, and became obsessed with the problem, obsessed to the point that a girl he was dating concluded that there was "something wrong with him" and that his mother "should take him to a doctor."

This one is REALLY good. It takes him a few minutes to get to the radio stuff, but it is worth the wait. More to follow. EXCELSIOR! FLICK LIVES!

Thursday, January 18, 2024

Some Great Reading Material -- Links to Radio Publications

 


My fellow Hambassador Dave WA1LBP sent this to me today (from Taiwan, I think).  Lots of great  ham radio and SWL info in these many publications.  The one that caught my eye was "The Modulator,"  an ARRL publication done by the 2nd District in the 1920s.  Really interesting.  I will sent this to Lyle, W7QCU who has an interest in radio from this era.   


Thanks Dave!  73! 

Sunday, January 14, 2024

QRP Trigger Warning! 500 kW from WLW (great video)


Wow, this video will make you appreciate the simplicity of QRP! 

My favorite part was when they required the use of "dark welding goggles" for whoever was charged with a visual check of  the tube filaments.  

Thanks to Hack-A-Day for alerting me to this wonderful video. 

Friday, November 24, 2023

A FREE Book from the Early Days of Ham Projects with Transistors: The CK722 -- The Device that Got Pete Juliano Started in Homebrew

 
Pete N6QW sent this amazing book to me this morning.  Pete wrote: 

"The book was the size of a Notebook and had a gray cover. I built some of the projects like the CPO. If you had a CK722 then you were there."

You can get the book for free here: 


 http://n4trb.com/AmateurRadio/RaytheonTransistorApplications/Raytheon%20Transistor%20Applications.pdf 



The impact of the CK722 on Pete Juliano, on ham radio, and eventually on SolderSmoke was quite profound. Back in 2015,  I wrote about this on the blog

I knew Pete had a lot of experience with transistors, but I didn't realize just how far back this experience reaches.  Pete writes, "The March 2015 issue of QST  had an article about a 1953 transistor transmitter project which was really advanced technology since the transistor was only invented about 5 years before that time...  About 1953 at the age of 11, I built my first solid state audio amplifier using the venerable CK722 from Raytheon. The transistor did look a bit strange in that cool blue cube shape with a red dot on the side to identify the collector. What a joy and surprise to me that it worked the first time power was applied...  It  was the CK722 that in large measure started me on a life’s work and engagement in a wonderful hobby. That CK722 path also led me to designing and building a QRP solid state version of the Collins KWM2 which I call the KWM-4."  I asked Pete why an 11 year-old kid in 1953 felt compelled to build a solid state audio amp.   The answer is very cool:  Pete's father had introduced him to crystal radios at age 8.  Pete wanted an amplifier for his crystal set, but his dad was worried about him building high voltage tube gear.  So that's how Pete got his VERY early start with transistors.

We are really lucky to have Pete Juliano sharing his vast tribal knowledge with us.

----------------

You can see a complete set of SolderSmoke posts about the CK722 here: 

Wikipedia has a nice article on the CK722.  The design contest Raytheon sponsored would be the kind of contest we could really get into!  https://en.wikipedia.org/wiki/CK722

Thanks Pete.  And thank you Raytheon! 

Thursday, November 16, 2023

The Grid Leak Detector -- Follow-up from Yesterday's Post on the Whole Earth Catalog's "Hippy" One Tube Receiver

Click on image for a better view
When I first looked at it in the Whole Earth catalog circuit, I thought it was a regen.  But a commenter correctly questioned this conclusion.  I remembered the grid leak circuit (WN2A provided more info in the comments).  This morning I found a Wikipedia page that explains it all very well.  I especially like the description of how this detector works both with small signals in the "square law" range of the tube, and with larger signals in the linear range of the tube.  The history of the discovery of the need for the large resistor is also very interesting.  I remember building FET amplifiers and finding that they would -- after time -- shut down.  This would happen as charge built up on the gate.  I had neglected to include the normal 100k ohm resistor (that would "leak" this charge to ground).  Once I put this resistor in, the amp worked fine.  

Here is the Wikipedia article:  


Sunday, October 15, 2023

Spy Rigs, Para Sets, Bugs, and Enigma Machines -- Dr. Tom Perera W1TP (video)


This is a really amazing presentation by Tom Perera W1TP to the Fairlawn (NJ) Amateur Radio Club. 

There is so much great info in this presentation.  Some of the highlights for me: 

-- The U.S. Civil War telegraphic (wired) spy set was just mind blowing.  I had never heard of this.  

-- The way the Nazis transmitted a signal 1 kc off the BBC frequency, so that Germans who tuned their Nazi-issued receivers to the BBC could be detected by neighbors (from the resulting 1 kc tone!) and turned in to the Gestapo.  

-- "Things don't land gently when dropped by parachute." Indeed.  This was a reminder of the courage of the young women who parachuted into Nazi-held territory during WWII.  Like Paulette.  It was great to see her with her Paratrooper wings on.  AIRBORNE!  And the picture of the operator with the bicycle generator was of Virginia Hall.  See: https://www.npr.org/2019/04/18/711356336/a-woman-of-no-importance-finally-gets-her-due  That portrait hangs in the hallway of the National War College. 

-- How they put the schematic of the PRC-5 right into the box.  Great idea.  But it had a terrible receiver.  One of the schematics showed a 455 kc IF and a BFO.  So they sent in superhets, not just regens. 

N2CQR operating the Para Set of G3ROO around 2009

This video makes me want to build a Para Set. 

Thanks a lot to Tom W1TP and the Fairlawn ARC. 

Saturday, August 19, 2023

Valveman -- The Story of Gerald Wells


Don't be deterred by the annoying test patterns at the start of this video.  Just skip past them.  The rest of the video is quite good.  Or you could just click on this link and avoid the first 83 seconds of test pattern:  https://youtu.be/Y8w6iwaAGJ4?t=83

Gerald Wells has been mentioned on this blog before, but I don't think we've ever presented the full documentary on this fellow.  Here it is.  Gerry is clearly one of us: a radio fiend, obsessed (as he admitted!) with wireless, a victim of THE KNACK.   

George WB5OYP of the Vienna Wireless Society got to meet Gerald Wells and visit his museum. George alerted me to this video.  Tony G4WIF also was able to visit Gerry and his museum. 

The documentary is full of interesting stuff, and is, in itself, a Knack Story.  Wells mentions the Crippens murder so well described by Eric Larson in "Thunderstruck."  It was this crime that brought radio to the center of public attention.