Look closely! IBEW! WYKSYKDS! But where was this?
Have any others like this been spotted?
Sunday, May 1, 2022
Thursday, April 28, 2022
Wednesday, April 27, 2022
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.
Tuesday, April 26, 2022
Level UP EE Lab Builds a Superhet Receiver
I was really glad to have stumbled across Darren's YouTube channel:
Heck, he has an S-38E on the shelf above his bench. He is clearly one of us. What is his callsign?
This morning I watched the first and last of his 10 videos on his superhet receiver project. Very cool. Lots of good info in there. And there is something for everyone: Arduinos and Si5351s, along with a lot of standard analog circuitry. The first episode appears above.
The variable bandwidth filter looks very interesting. And there was a nice shout-out to Charlie Morris and one to Hans Summers.
I really like his effort in episode 10 to measure Minimum Discernible Signal using commonly available test gear. This helped me in my effort to get more rigorous and serious about receiver performance measurement.
Darren has many other excellent projects on his YouTube channel. My Hammarlund HQ-100 receiver started giving me trouble this week, and I was debating whether or not to fix the old thing. Darren's channel provided the inspiration I needed. It will be fixed!
Please subscribe to Darren's channel. And spread the word about his videos. We definitely want him to make a lot more.
Thanks Darren!
Words of Wisdom on Which Tools to Buy
Also interesting are Van Neistat's thoughts on workshop design:
Monday, April 25, 2022
75/20 - 17/12 Two Homebrew Rigs in Scrap-Wood Boxes
I moved the 17/12 Rig off the workbench and placed it (as planned) atop the Mythbuster rig. Now I have four bands easily accessible. In these pictures you can see all four bands being displayed on the San Jian Frequency Counters.
I found a kitchen drain screen that is an ideal cover for the 3 inch speaker in the 17/12 rig.
I reconfigured the Low Pass filters in the CCI .1 kilowatt amplifier. I put a 12 meter LP filter in there in place of the 40 meter LP filter (that I haven't been using much).
I have been working a lot of DX on both 17 and 12.
Sunday, April 24, 2022
Back to the 1970's! Homebrew Keyboards! Don Lancaster's TV Typewriter
Even though it is outside my normal analog comfort zone, I really liked this video. Farhan sent it to me, along with this note:
--------------
As a kid, do you remember Don Lancaster's books? I learnt most of my digital electronics from him. I still have the 7 dollar video generator book on my shelf. He predates the Homebrew Computer Club. In fact, he is probably the reason for the HCC, because he put in the pieces that were used by others like the two Steves to build their own computers.
His most brilliant hack was to build a "TV typewriter" out of standard TTL parts that were just coming out in the surplus market. For $120, you could, if you build etched your own PCBs and managed to pry parts of fellow builder's dead fingers, build a circuit that, if you typed your name, it showed up on the TV screen! Never mind that dad wanted to get back to watching football or mom wanted the kitchen counter to be cleared out. Those days, parents had no appreciation for their kids being on TV, I guess.
In an earlier hack, he encouraged people through his articles in Radio Electronics to build their own Qwerty keyboard. With this in hand, you could, um .. um... well type something and sit back. There was nothing to connect it to. The fun thing was, there were no key switches available. You had to build those as well. Wind your own springs, make your own keytops, Once it was built, you could use a VOM to check that the ASCII bits corresponding to the key you held down would correctly show up on the 7 data lines. I guess the girls were surely impressed. You just needed to carry the power supply with +5, -5v, +12v, the keyboard itself, an ASCII chart and a VOM to school to show off.
Jokes apart, he kept building things and builds them to this day. His TTL cookbook and CMOS cookbooks were the goto books for almost all digital elecctronics hackers. It is a pity that no one acknowledges his knack. He has scanned in a few of his books on his 1990s www.tinaja.com. Check https://www.tinaja.com/ebooks/
Why does it concern us? He is K3BYG, that's why.
Watch this https://www.youtube.com/
- f-----------
So many things from the video resonated with me:
-- The importance of building and testing, stage by stage. The narrator admits "I might have screwed that up."
-- Homebrew keyboards! Make your own keyboard springs you pathetic appliance operators!
-- Wood box.
-- Origins of ASCI
-- The scary 1970s. Indeed. I started High School in 1972.
-- Schematic errors! Oh the humanity! Erratas.
-- Appeals to the Digital Gods. (Not as powerful as The Radio Gods.)
-- A Gimmick Twin Lead.
-- "So many different disciplines went into building this thing..."
-- A taste of the home computing revolution of the 1970s.
-- Farhan is right -- he was K3BYG. But that call now seems to belong to someone else.
Don Lancaster's unofficial autobiography:
https://www.tinaja.com/glib/waywere.pdf
Clearly, Don Lancaster has The Knack!
Saturday, April 23, 2022
Looking at the World Through a 1 inch Cathode Ray Tube (the RCA 913) (videos)
Joh DL6ID sent me the above video. We have been e-mailing each other about the W9YEI Television Receiver built in 1939 or so. We have kind of concluded that the builder used an RCA 913 tube as the CRT. This was an oscilloscope tube and was often described as looking like a metal 6L6 with a tiny screen on top. This is kind of neat -- like using something from the old days to peer into the new world of video.
We wondered about the image persistence of this tube. Fortunately for us, we found several YouTube videos showing recent builds or repairs of oscilloscopes with RCA 913 tubes.
Of course, Mr. Carlson has a video on one of these devices (and -- as expected -- has another in his junk box. Mr. Carlson has at least two of everything.)
Here are a few other videos showing RCA 913 tubes in action.
https://www.youtube.com/watch?v=IfN2mmEIfTE (with Men at Work audio)
https://www.youtube.com/watch?v=TJF22Ra2kIM (Summertime.... And the Livin' is Easy)
Here's a nice video from Tektronix on CRTs:
Friday, April 22, 2022
1942 (?) RCA Film on Tubes, Radio, Research, and Television
Here is a very interesting video from RCA. It was released in 1942, but it looks to me as if it was produced BEFORE the Pearl Harbor attack and the U.S. entry into World War II. There is no mention of the war nor of RCA's support for the war effort. All films like this that were produced during the war have a lot of material about how the company was contributing to the war effort. So I think this is really a pre-war film.
Early in the film they link the origins of RCA Labs to a decrepit "radio shack" at Riverhead, Long Island (NY) in 1919. Here is some background on this:
and
In this film we see Vladimir Zworykin (boo, hiss) of TV fame (no mention of poor Philo Farnsworth), and we also see Harold Beverage, the creator of the antenna that bears his name. There is what must have been one of the first "electronic clocks."
At the end, the segment on television is really interesting. It is amazing how far they had gone with TV before the war.
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