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About John

  • Rank
    Will I break 10 posts?
  • Birthday 09/19/1981

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  • Interests
    Amateur Radio, Telecommunications
  • Location
    Western Pennsylvania

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  1. Greetings again, Just a follow-up... Televisions listen on the same spectrum as well. They have wide receivers for television audio, which starts around 54 MHz for Channel 2 and ends somewhere around 216 MHz for Channel 13. Keep in mind that with approximately 800 mW of energy from a transmitter near another receiver, like your television, for example, will easily penetrate the receiver, thus enabling you to hear the telephone. They're all synthesized, yes, but the back-end is driven by quartz crystal to keep accurate frequency. In standard operating temperature, quartz crystals usually keep +/- 10 parts per million (ppm) accuracy without a crystal oven to maintain temperature. Even the best solid state equipment cannot accurately time or keep frequency like that without quartz crystal control somewhere. Essentially, most analog and all digital watches are even quartz driven. Regards, John
  2. Greetings, I'll try to explain in detail what you're hearing, and more importantly, why you're hearing it. Often FM (and sometimes even AM) radios will pick up on cellular carriers. Specifically, you're basically hearing digital packets en route to the carrier, signalling your phone's status to be able to intercept or handle a call. The cellular telephone itself makes a string of noises because the carrier is digital, which means the phone is basically encoding and decoding data with the carrier. So, it won't be anything very intelligable. Most every RF device was designed on a low frequency circuit and is then multiplied through synthesis to generate higher frequencies. This happens because basically all RF equipment types are based on quartz crystals to resonate on frequency. If you've never seen a crystal, they're usually a two pin component in a flat, rounded metal case, and are often smaller than the size of a Lincoln penny. I scrounged Google and robbed an image which shows several crystals in a row. Crystals contain quartz, which is cut into thin wafers. The size of these wafers determines the frequency that the crystal oscillates (resonates or vibrates) on when electrical energy is applied. And since we only have the (affordable) technology to cut wafers up to certain size to produce a certain range of frequencies, it makes more sense to use low frequency crystals and then multiply frequencies through synthesis to achieve the desired result. So, upon multiplication, a "harmonic" or low level emission of energy (transmission) appears. FM radios cover 88 to 108 MHz and thus have a 20 MHz space to pick up any number of harmonics that just might land somewhere on the dial. So, you won't find it uncommon for a radio, or even for speakers to pick up on concentrated energy levels from your cellular telephone or any other RF emitting device that you happen to have laying around. I hope that clears things up. Regards, John
  3. Do I need an introduction? ;-)
  4. Strom, As mentioned, physical access isn't necessary. I prefer Gentoo myself, but there are other options. Gentoo has a site for doing alternative installations...: I've also seen a few others, for example, installing Debian...: And, if you want to go to FreeBSD, here's another option...: Obviously, the conventions in some of these documents are directly applicable to other distributions. Your mileage may vary a bit. Good luck! If you need help, give me a shout. Regards, John