ElectroBOOM! CuriousMarc Tries (and fails) to fix an old HP182C Oscilloscope -- Words of Wisdom for all Homebrewers

"You try your best to improve something that already almost works... and then you ZAP it entirely in the process.  This is the worst feeling ever.  But don't kick yourself.   This is our lot.  We are made to suffer." CuriousMarc

Indeed.  Take heart homebrewers.  Even CuriousMarc (who is a ham!) has been there and done that. 

This particular CuriousMarc episode was, I think, especially good: 

-- It reminded me of WHY I gave up on my beloved Tek 465 and went with Rigol DSO scopes.  I found I was fixing the Tek scope too often.  Plus, my Tek 465 had PLUG-IN TRANSISTORS.  Yikes!  One false move and you would insert 2 or 3 new problems into the already broken 'scope.  The high voltage in there was really scary.  I had to borrow a high voltage probe from Alan W2AEW.  I survived, but we shouldn't have to risk our lives for hobby test gear!

-- I would advise all homebrewers to be more careful around the really high voltages you will find in old 'scopes and TVs.  Remember the lesson of Ross Hull:

https://www.wia.org.au/members/contests/rosshull/documents/Ross%20Hull%20-%20VHF%20Pioneer.pdf

Read the article that starts on page 7:

 https://www.rsp-italy.it/Electronics/Magazines/QST/_contents/QST%201938_11.pdf

-- Marc struggled with a junction FET.  This reminded me of the raging J310 debate on the Discord channel for the SolderSmoke Direct Conversion Receiver. 

-- We see the oscillator signal flat-topping when it turns on the diodes -- again DC RX memories. 

-- Marc had trouble seeing how the oscillator would start.  I too had trouble understanding how an oscillator would get going. 

-- At one point Marc replaced a transistor with a device that grounded the drain.  This will happen if you switch too quickly from say an RD06 to an IRF-510.   With the IRF-510 you need to insulate the tab from the grounded heat sink.    

It will be great to see, in subsequent episodes, how Marc makes it work.  It is really great to see someone present an unvarnished view of how troubleshooting really works.  

Thanks Marc.   73 

Here is Marc's YouTube channel:

https://www.youtube.com/@CuriousMarc

Paul K9ARF -- SolderSmoke and a Knack Story

Bill:

Having been an occasional Solder-Smoke listener, I recently purchased your book "Solder Smoke Adventures" to read during vacation.  Previously I limited reading material to technical material, but I retired two years ago and can now allow myself to read stuff just for fun.  I devoured your book.

I found you and I to be kindred spirits, seeking to understand the mysteries of electricity and electromagnetic waves as we follow life's path.  We're close to the same age, you're a couple years my senior.

My fascination with electronics began as a boy when my Dad and I put together a crystal receiver as a Cub Scout project.  I fondly remember my father scrambling up on the roof to string a long wire as an antenna, and then listening to the Cubs ballgame in the earpiece.  No batteries required!

I exhibited "knack" tendencies later as an early teen.  At a local estate sale I picked up some magazines teaching basic TV repair, and a box of parts that previously was a portable B/W TV.  My family was amazed when I resurrected that little TV set.

My career path went into audiovisual interests - I heard broadcast engineers made a lot of money, so I went to Milwaukee Area Tech College electronics communications program.  The students there ran UHF channel 36 alongside the professionals running TV channel 10 (both pbs affiliates).  On the way to getting your 1st class "phone" license, we learned 2way radio (2nd class).  I found that repairing things was far more fun than pushing buttons in Master Control, so I ended up working in 2way.

While attending MATC, I met some guys who were hams - and they invited me to my first-ever hamfest.  Wow.  A gathering of electronics enthusiasts, many who also have "the knack".  I purchased a couple of old books cheap, not knowing this would steer my life in the future: the antenna book and a 1970s radio amateur handbook, both from ARRL.  Reading these books, I was intrigued by people who design and build their own equipment - the ultimate in coolness!

I guess what really kept me interested in reading your book is your desire to understand the basic building blocks of electronics - how does it work?  This mirrors my personal experience.  Though I have formal electronics training, my schooling was aimed mostly at troubleshooting, finding the malfunction.  The understanding of why the components in a circuit are the values specified and how they produce the desired output was, like you, a lifelong learning process I still work on today.

My adventure into Amateur Radio was delayed by life activities: marriage, a house, and a child.  It didn't help that I never met any hams in rural north Wisconsin.  I finally met an amateur who was a VE, and Radio Shack study materials had me on the way in 1990-91.

I tested in early '91 and passed the Novice, Tech, and 5 wpm code - the VE knew that I was a career radio tech, and at his urging I passed the General written test too.  My initial call was N9KQX (a horrible cw call).  The next months had me work on my code speed and study the Advanced material, and later I became KF9GQ.

At that test session, I sat alongside a gentleman who was taking his 20 wpm code test (wow).  A few months later he was one of my interviewers as I applied for a new job - Radio Tech for the Electric & Gas utility in Green Bay.  I believe my ham radio hobby helped me land that position, which I held 30 years to retirement.

When the vanity call sign program started, I changed my call to K9ARF "amateur radio fun" (yes, I like dogs...) or "analog radio fan" - life must include a sense of humor.

In my years as a ham, I have done quite a bit of homebrewing, from repeaters and accessories for my station, to test gear and complete transceivers.  My proudest projects were building W7ZOI's spectrum analyzer and a multiband KK7B based phasing transceiver using AA0ZZ's DDS synthesizer kits.

I want to thank you and the other solder smoke guys for what you do.  Hopefully I will someday have an opportunity to meet you in person to share a cold beverage, laugh and tell stories of molten solder variety.  Keep up the good work!!

73 de K9ARF Paul, Green Bay, Wisconsin

Britain's EF-50 Valve (Tube, Thermatron) in WWII

Thanks to Rogier PA1ZZ for sending us this. 

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:

https://youtu.be/Xjvr5qCKYWc?feature=shared

 

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

https://www.haystack.mit.edu/news/founder-herb-weiss-celebrates-haystack-history/

  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:

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=913698

"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:

https://maineboats.com/print/issue-178/still-boating-after-all-these-years

  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 

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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! 

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.    

Watch Mr. Wizard! 1952 Program on Electromagnetism. And more! (video)

Wow.  This is a very thought provoking program.  It is kind of like "Mr. Roger's Neighborhood," but with science. The lessons provided by Mr. Wizard are really good, but one shudders to think about doing the these experiments with kids (or even with adults!) in today's world.  Here are a few of things that would cause trouble today:  

-- Liquid mercury.  

-- A big power supply. ("Here Willy, you hold the positive terminal.") 

-- Even the sprinkling of iron filings would probably require masks at a minimum.  

-- In the end, letting poor Willy drop to the floor when Betsy turns off the electromagnet that was holding his swing in the air.  

-- And of course, poor old Mr. Wizard's affinity for the kids would stir suspicions. 

We also see a sad and very early example of the influence of advertisers and what they call today "product placement."  Note the fairly obvious plug (via Morse Code!) for breakfast cereal.  In the credits you will see that the program was sponsored by "The Cereal Institute."  What next kids?  Cigarettes? 

But there is a lot of virtue in this program:  The development of the telegraph key, Morse Code,  CW sidetone.  Unlike many of the Box Top Extras of today, young Betsy was not afraid to wind a coil.   

We should all embrace the spirit of Mr. Wizard.  We are, after all, the International Brotherhood of Electronic WIZARDS!  These experiments reminded me a lot of the Trivial Electric Motor that my son Billy and I made when he was around Willy's age (thanks for the idea Alan Yates).  

Thanks to Chuck KF8TI for alerting us to this show.  Chuck says this program was an early influence on him, and was one of the things that provided a connection between the theory he was learning in college and the real world of electronic devices. 

Many more great programs like this can be found on Mr. Wizard's YouTube Channel: 

https://www.youtube.com/user/MrWizardStudios   Please let us know if you find other videos (on this channel or elsewhere)  that will be of special interest to the IBEW. 

Finally, color TV in 1952?  That seems a bit early for color.  What do you folks think was happening here? 

The Story of Television (Sarnoff's Version) -- 1956 Film

Of course, this has to be taken with a huge grain of salt.  "General" Sarnoff sits there and claims that Vladimir Zworkyin "invented" electronic television.  But Philo Farnsworth really did that.  Zworykin's claim to invention has about as much validity as Sarnoff's claim to having been a General!  

But still, there is a lot of interesting info amidst the RCA propaganda.  Again, it is really striking how far they had come before WWII put things on hold for four years.