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Johnythree

HN member
Joined
Sat, Aug 02, 2014, 3:18 AM UTC
HN karma
812
Public activity
556 items

About Johnythree

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Recent public activity

  1. comment
    Comment #43373067

    I'm puzzled by this claim. I wouldn't call it a myth, but all the same... I grew up on a vineyard. Each harvest time the grapes would hang down heavily and almost touch the ground.…

  2. comment
    Comment #41961546

    AM is a type of modulation which is widely used by many different services (eg Shortwave broadcasting, CB radio, Aircraft VHF, etc). However "Longwave and Mediumwave Broadcast" una…

  3. comment
    Comment #41961488

    Transmitters need only be re-certified if they are to be sold in quantity. Once-off Broadcast Transmitters need only demonstrate that they meet the relevant standards. Many of the …

  4. comment
    Comment #41837551

    It doesn't. In both it depends on what the stations engineer chooses to transmit.

  5. comment
    Comment #41837522

    Most cheap FM receivers definitely use a PLL to detect FM. Giving automatic tuning is just a side benifit.

  6. comment
    Comment #41837501

    Most FM receivers can lock on the carrier because they have a "Phase locked loop" to cancel any tuning errors. Many good AM receivers do exactly the same thing, especially those re…

  7. comment
    Comment #41837448

    Is commonly known as "Bass Boost". As the OP has said, it cannot give louder bass, but simulates the bass harmonics.

  8. comment
    Comment #41837419

    This is yet another myth: The "Woolyness" of AM broadcast (at least in America) is due to the stations purposefully tailoring their audio processing to suit typical cheap AM receiv…

  9. comment
    Comment #41837353

    Only while signals are strong. On weak signals however, AM has a considerable benefit in intelligibility over FM.

  10. comment
    Comment #41837347

    This is a myth. There is no reason that channel spacing need limit the modulation bandwidth. The only downside is that listeners to adjacent stations will hear a slight "monkey cha…

  11. comment
    Comment #41837298

    Yes, this is one of the proposed methods. It's known as "Independent Sideband". It works, but it is a fairly expensive method to implement.

  12. comment
    Comment #41837277

    There were a number of successful AM stereo broadcasting methods proposed and trialed. These were completely compatible with conventional AM transmissions. The conceptually simples…

  13. comment
  14. comment
    Comment #41837130

    There is no reason that the channel spacing need limit the sideband bandwidth. The only downside to this is that listeners on adjacent stations hear a slight "monkey chatter" from …

  15. comment
    Comment #41478200

    The pickle will shunt (steal) some signal, but the radiated power from the antenna will be very much greater than that flowing through the pickle.

  16. comment
    Comment #41478191

    Because your nerves don't respond to high frequencies, you cannot "feel" RF current. What you do feel is the intense burning associated with the RF energy being converted to heat.

  17. comment
    Comment #41478149

    You have it backwards: Fessenden is famous for developing a electomechanical RF generator which put out a clean sinewave (eg a coherent wave), which helped replace the earlier Spar…

  18. comment
    Comment #40509453

    Or even simpler, use a Neon bulb. or even a Fluro light.

  19. comment
    Comment #40437507

    The alternative is to do the standard sitting exercises intended to avoid DVT. eg wiggle your toes, flex your leg muscles, rock your feet, etc. All you need do is avoid pinch point…

  20. comment
    Comment #40437416

    There are simple exercises that you can do while seated to avoid DVT. Just wriggling your toes help a lot, or flexing the muscles in your legs. I fly a lot on routes over the tropi…

  21. comment
    Comment #40366168

    Likewise "Pavane", an alternative history science fiction novel by British writer Keith Roberts.

  22. comment
    Comment #38935599

    Any Antenna designer wants to see the antenna being an elevated ground-plane or dipole mounted clear of obstructions well above the phone. However he is stuck with a compromise des…

  23. comment
    Comment #38935383

    > antenna is tuned to the maximum allowed emission power per local regulations Actually it's not. The antenna is tuned to give a peak in output. It's either correctly tuned, or it'…

  24. comment
    Comment #38935276

    Different body positions are going to affect the antenna tuning differently. And of course different surroundings will also effect the directivity (eg the radiaton pattern). So som…

  25. comment
    Comment #38922935

    A more likely theory is that the fob transmitter (and antenna) is tuned to put out max signal when near the body. This is it's normal use. If however you tested it with the fob som…