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.