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Ah yes the Smith Chart. The physics equivalent to programming punch cards.

by Vysero 7y ago

jessaustin 7y ago
Is this comparison based solely on the idea that both of these tools are outdated? If you have something deeper in mind, could you fill in some details of this metaphor? I haven't seen Smith charts before, but a cursory read of TFA doesn't really evoke punch cards.
- segfaultbuserr 7y ago
  Smith Chart is both a visualization tool (as a chart) and a calculation tool (as a nomogram), you can use a printed Smith Chart to do RF-related calculations (impedance matching, return loss, etc) with a ruler and compass on a graph paper, pretty much like using a slide rule to calculate logarithm and trigonometry. I think it's why the OP compared it to a punch card. It's true that today it's rarely used as a calculation tool, but it's still useful as a visualization. I don't think it's obsolete like punch cards.
jjoonathan 7y ago
Punch cards are made thoroughly obsolete many orders of magnitude over by modern storage and IO technologies. What replaced Smith Charts? The >$100k only-a-few-years-old VNAs next room over still plot S11 and S22 on Smith Charts and I'd bet you an entire VNA that this will still be the case in 10 years. Preemptive: No, 3D Smith Charts do not obsolete Smith Charts, just like 3D line charts don't obsolete 2D line charts.
- kstrauser 7y ago
  > Punch cards are made thoroughly obsolete many orders of magnitude over by modern storage and IO technologies. You weren't kidding. From https://en.wikipedia.org/wiki/Punched_card_input/output https://en.wikipedia.org/wiki/Punched_card_input/output : > If all columns of an 80 column card encode information this translates to approximately 2,500 characters per second (CPS). According to https://www.techradar.com/reviews/samsung-970-evo-plus https://www.techradar.com/reviews/samsung-970-evo-plus a 970 EVO Plus SSD is about 1,400,000 times faster. Wow. I would love to go back a few years and blow young me's mind.
- Vysero 7y ago
  Well in my EMAG class in college we were introduced to Smith Charts. We studied them for about a week or two and used software to check our work. So software has replaced them. There is nothing a Smith Chart can do that a simple software application can't manage in 1/16'th the time.
CamperBob2 7y ago
A severely misguided analogy. Every VNA made to this day supports a Smith chart display, and every credible course on RF engineering covers them. Meanwhile, nobody who's not involved in running a computer museum uses punch cards for anything, and there's little or no pedagogical value in continuing to teach IT or CS students about them.

Ah yes the Smith Chart. The physics equivalent to programming punch cards.

by Vysero 7y ago

Ah yes the Smith Chart. The physics equivalent to programming punch cards.

Is this comparison based solely on the idea that both of these tools are outdated? If you have something deeper in mind, could you fill in some details of this metaphor? I haven't seen Smith charts before, but a cursory read of TFA doesn't really evoke punch cards.

segfaultbuserr 7y ago
Smith Chart is both a visualization tool (as a chart) and a calculation tool (as a nomogram), you can use a printed Smith Chart to do RF-related calculations (impedance matching, return loss, etc) with a ruler and compass on a graph paper, pretty much like using a slide rule to calculate logarithm and trigonometry. I think it's why the OP compared it to a punch card. It's true that today it's rarely used as a calculation tool, but it's still useful as a visualization. I don't think it's obsolete like punch cards.

jjoonathan 7y ago

Punch cards are made thoroughly obsolete many orders of magnitude over by modern storage and IO technologies. What replaced Smith Charts? The >$100k only-a-few-years-old VNAs next room over still plot S11 and S22 on Smith Charts and I'd bet you an entire VNA that this will still be the case in 10 years. Preemptive: No, 3D Smith Charts do not obsolete Smith Charts, just like 3D line charts don't obsolete 2D line charts.

kstrauser 7y ago
> Punch cards are made thoroughly obsolete many orders of magnitude over by modern storage and IO technologies. You weren't kidding. From https://en.wikipedia.org/wiki/Punched_card_input/output https://en.wikipedia.org/wiki/Punched_card_input/output : > If all columns of an 80 column card encode information this translates to approximately 2,500 characters per second (CPS). According to https://www.techradar.com/reviews/samsung-970-evo-plus https://www.techradar.com/reviews/samsung-970-evo-plus a 970 EVO Plus SSD is about 1,400,000 times faster. Wow. I would love to go back a few years and blow young me's mind.
Vysero 7y ago
Well in my EMAG class in college we were introduced to Smith Charts. We studied them for about a week or two and used software to check our work. So software has replaced them. There is nothing a Smith Chart can do that a simple software application can't manage in 1/16'th the time.

CamperBob2 7y ago

A severely misguided analogy. Every VNA made to this day supports a Smith chart display, and every credible course on RF engineering covers them. Meanwhile, nobody who's not involved in running a computer museum uses punch cards for anything, and there's little or no pedagogical value in continuing to teach IT or CS students about them.