Talk:Spark-gap transmitter

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Banned in the 1920's?[edit]

Should it be mentioned that spark-gap transmitters were banned for use in the USA? (Besides special allowances) TinyTimZamboni (talk) 16:09, 7 March 2013 (UTC)

Untitled[edit]

Model T magneto only delivered 30 volts; could this refer to the model T spark coil, the universal experimenters' high voltage source of past generations? Gzuckier 18:32, 22 November 2005 (UTC) . Yes, definitely. Gutta Percha (talk) 10:31, 25 July 2008 (UTC)

pic[edit]

Good addition. Doesn't it need a key (or switch)? Gzuckier 19:07, 21 December 2005 (UTC)

duplicate info[edit]

As far as I can see, the end of the Operation section is almost exactly the same as the Spark Gaps - Construction section. I do not understand why my edit to remove the duplicate paragraphs was reverted? StealthFox 00:17, 8 April 2006 (UTC)


legality?[edit]

http://www.amazon.com/gp/customer-reviews/discussions/start-thread.html?ie=UTF8&ASIN=0262082985&authorID=A70SVUQ397Q8Y&store=yourstore&reviewID=R5CL51KHLNJS6&displayType=ReviewDetail

According to this, and other websites, Spark gap tranmitters have been illegal since the '20s. should this be mentioned? --24.252.10.228 00:20, 20 July 2007 (UTC)

I've seen several in operation. I can't imagine why they'd be illegal or where that would be. — Preceding unsigned comment added by 108.202.113.201 (talk) 09:56, 5 April 2012 (UTC)

The radio waves emitted by spark-gap transmitters, called damped waves, are noisy and have a wide bandwidth, so they can interfere with other radio signals. In 1938 the International Telecommunications Union prohibited this type of emission (called "class B") to get the last spark-gap telegraphy transmitters off the air, and it is still prohibited in all nations. Title 47 of the FCC regulations has the prohibition in a footnote at the bottom. Radios are a lot better now, but hobbyists playing with spark-gap transmitters in their garage can still piss off neighbors by interfering with broadcast TV reception and perhaps other radio services. I'd guess the FCC is too busy to track down spark-gap transmitters unless someone complains. --ChetvornoTALK 16:53, 5 April 2012 (UTC)

Crude Technology ?[edit]

The article claims that "Marconi's ... first transmitters were extremely crude". Well yes, they were crude by today's standard, but at the time they were quite literally "state of the art". I will re-word this section Gutta Percha (talk) 09:36, 25 July 2008 (UTC)

Other type transmitters?[edit]

The article states: "With the other types of transmitter, the carrier wave could not be controlled so easily, and elaborate measures were required both to modulate the carrier and to separate the receiving antenna from the transmitting antenna."

For the time-period cited, the only other type transmitters that I'm aware of were high-speed alternators. What other type transmitters of that period generated a constant carrier wave that needed to be modulated, as opposed to simply keying the carrier on-and-off?

Also, why would it be any more complicated to separate the receiving antenna from the transmitting antenna with the "other type transmitter" than with a spark-gap transmitter?

In short, the statement is extremely vague, and it lacks citation of a reliable secondary source.Ken (talk) 20:39, 7 March 2009 (UTC)

Upon re-reading the article, I realized that the phrase "other types of transmitter" was referring to an alternator or tuned-arc type transmitter. It's true that these type of transmitters generated a continous carrier; but regardless, the carrier was keyed/modulated in a fairly simple fashion via a telegraph key; albeit, not as simple as keying a spark-gap transmitter on-and-off.Ken (talk) 21:05, 7 March 2009 (UTC)

But how does it actually work?[edit]

This article has lots of history but doesn't actually explain the basic concept behind how does a spark gap create radio waves?

Modern high-school/grad physics will tell you about AM and FM but this is just alternating current in a wire - what is the discharge got to do with radio transmission? —Preceding unsigned comment added by 83.244.153.18 (talk) 14:50, 7 February 2011 (UTC)

One way to explain it, is that the spark gap doesn't create RF directly. Its main function is to discharge the capacitor through the tuned circuit, which oscillates on its natural frequency. SV1XV (talk) 16:53, 7 March 2013 (UTC)

Tesla worship[edit]

Thanks, Fountains of Bryn Mawr, for scaling back the claims of the Tesla groupies and putting Tesla's contributions in better perspective. The fact that this article mentions Tesla and doesn't mention Oliver Lodge, Ferdinand Braun, Augusto Righi, Jagadish Chandra Bose, Adolf Slaby, Georg von Arco, John Ambrose Fleming, or Max Wien's contributions to spark transmitters is blatant WP:UNDUE. These gentlemen must be spinning in their graves. --ChetvornoTALK 00:59, 4 November 2013 (UTC)

ty, Hunting down claims on Tesla turns up some real doozies, such as Tesla was Italian and invent AC[1] or that Edison invented DC and Tesla invented AC[2]. Radio cleanups have also been done by Martin Hogbin[3] although the "Tesla groupies" tend to revert them back without comment or rational. Fountains of Bryn Mawr (talk) 14:40, 4 November 2013 (UTC)
I am happy to help maintain due weight here if required. Martin Hogbin (talk) 15:09, 4 November 2013 (UTC)
Thanks. Wow, those examples are amazing! It's a difficult task, dealing with people who view history from such a single-issue (or single-person) perspective, kudos to you guys for taking it on. I know some editors are intimidated by the Tesla cult and avoid tangling with them, just because it is so time-consuming. This article has not seen their attention lately, the stuff Fountains of Bryn Mawr corrected was leftover from a while ago. In many articles, including this one, the problem is not so much false claims about Tesla but UNDUE weight because Tesla's contributions are the only ones mentioned; so the real solution is to write a proper history giving the contributions of others. --ChetvornoTALK 07:28, 5 November 2013 (UTC)
Re:"others", I agree, just fact checking claims gives me a whole new appreciation of the people you listed. They should be added into the space being freed up from bloated UNDUE. Fountains of Bryn Mawr (talk) 14:18, 5 November 2013 (UTC)