Rack of Tubes?

Discussion in 'Amplitude Modulation' started by AC0OB, Jun 29, 2019.

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  1. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    The assembly on the far left side looks like a lot of 6080 tubes. In high school, when I was in Army MARS, every other month they shipped 101-pounds of parts, wire, sometimes small equipment, and whatever. One time I got like 20 of the 6080 tubes in the shipment. I never did find a good use for them!

    Another time, I got 10-each inspection lights from B-29 bombers. Those had a 24-volt light on the end of a 10-foot long cord that was reeled into a metal box with a cover. The boxes were the perfect size for small projects.

    Glen, K9STH
  2. W1TRY

    W1TRY XML Subscriber QRZ Page

    I'm not alone in getting this reference, am I? :D
  3. N2EY

    N2EY Premium Subscriber QRZ Page

    "It's Hedley"

    "What are you worried about? It's 1874 - we can sue her!"

  4. N2EY

    N2EY Premium Subscriber QRZ Page

    Well, duh. See post #12. Follow the link. Look up ENIAC, EDVAC, ORDVAC and BRELSC-1.
  5. N2EY

    N2EY Premium Subscriber QRZ Page

    It isn't. It's part of ENIAC, which was built in the form of plug-in modules - LOTS of modules. None of the tubes are 6080s - they hadn't been developed when ENIAC was built. In fact, ENIAC used common receiving and small transmitting tubes, because they were available.

    ENIAC was designed and built at the University of Pennsylvania, where I went for my undergraduate degree. It was built for the Army, and when accepted in 1946 it was moved to the Aberdeen Proving Grounds, where it was used for almost 10 years.

    Most of those who did the actual construction and programming of ENIAC were women. Only now are they beginning to get the recognition they deserved from the start.

    I've seen and held parts of ENIAC up-close and personal, including modules like the one at the far left.They look almost homebrewed; the parts are familiar to anyone who knows 1940s electronics. The big challenge of building ENIAC was getting the parts in wartime, and in figuring out how to make it somewhat reliable given the low MTTF of the components used. One trick was to design the circuits to tolerate wide variations in component values. Another was to operate everything well below ratings. And since failures often occurred at startup, another technique was to simply let it run continuously whenever possible. Since ENIAC consumed about 150 kW, this wasn't an inexpensive option.

    Much of what we now take for granted when it comes to "reliability" started with ENIAC and other early computers.

    73 de Jim, N2EY

    Last edited: Jul 2, 2019
    W7UUU likes this.
  6. W7TFO

    W7TFO Platinum Subscriber Platinum Subscriber QRZ Page

    Those were the first days when kW & computers went into the same sentence. Now it is power-hungry Bitcoin miners...

  7. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    "...When the United States entered World War II, the Moore School of Electrical Engineering at the University of Pennsylvania undertook the building of an electronic computing machine for the Ballistic Research Laboratory. The principal designers were J. Presper Eckert, an electrical engineer at the Moore School, and John Mauchly, a physicist who had become interested in calculating devices from his efforts to apply statistical methods to meteorological data. Eckert and Mauchly designed the machine to compute ballistic tables, but recognized that it could be applied to a very wide range of problems..."

    "... All together there were 18,000 tubes, 70,000 resistors, 10,000 capacitors, 1500 relays, and 6000 manual switches. This equipment consumed 140 kW of power and filled a room 20 feet by 40 feet..."

    "...The architecture of the Eniac was base 10, not the modern day base 2 logic, with manual table sets to solve the second order differential equations for ballistic trajectories..."


  8. N2EY

    N2EY Premium Subscriber QRZ Page

    Yes, I know, I've read the manuals in the Moore School library. In 1976, some of the pieces and parts came back to the Moore School - I was one of the few who knew what they were. I could have walked out with part of ENIAC, but I didn't - it would have been wrong.

    John Mauchly was interested in weather prediction when he was at Ursinus College.

    ENIAC was the first electronic, high-speed, Turing-complete, general-purpose digital computer. Other claimants for the title of "first computer" fail for various reasons, ranging from being electromechanical, slow, not Turing-complete, and/or being special purpose machines.

    ENIAC's design was modified in its time at Aberdeen. Though its primary purpose was computing gun aiming tables, it was used for many other purposes, some of them classified.

    ENIAC is the direct ancestor of all modern digital computers.

    In 1996, for the 50th anniversary of the announcement of ENIAC, part of the machine was reassembled and made to work again. All it could do was add two numbers, but it worked.

    Maybe I should volunteer to help them get it working for the 75th anniversary.....


  9. W0RIO

    W0RIO Ham Member QRZ Page

    That reminds me of this quote:
    Base 8 is just like base 10 (if you're missing 2 fingers) - Tom Lehrer
    AC0OB, KD2ACO and N2EY like this.
  10. N2EY

    N2EY Premium Subscriber QRZ Page

    Almost 60 years ago - relevant today


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