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Thread: Most useful voice DXing modulations?

  1. #1

    Default Most useful voice DXing modulations?

    What is a suite of voice modulations to best increase my odds for long distance contacts?

    I'm researching mobile radios to buy for my jeep to make long distance voice contacts and Im getting the impression SSB is necessary. I was focusing on Quad band radios, 0.7, 2, 6 and 10 meter radios but all Ive seen are FM only. Initially I want to do some interesting long distance contacts while out camping in western deserts or mountains and perhaps ultimately DX contesting. I have a General license.

    Some advise would be appreciated. Thanks!

  2. #2

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    Quote Originally Posted by rkruz View Post
    What is a suite of voice modulations to best increase my odds for long distance contacts?

    I'm researching mobile radios to buy for my jeep to make long distance voice contacts and Im getting the impression SSB is necessary. I was focusing on Quad band radios, 0.7, 2, 6 and 10 meter radios but all Ive seen are FM only. Initially I want to do some interesting long distance contacts while out camping in western deserts or mountains and perhaps ultimately DX contesting. I have a General license.

    Some advise would be appreciated. Thanks!
    this made me smile.

  3. #3

  4. #4
    K7KBN's Avatar
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    On those four bands right now, an "interesting long distance contact" would be via repeater IF you were lucky. Maybe into the next state. On VHF and above, virtually all of the voice communication is on FM. As a General, you have other available choices for bands and modes.

    But you knew that. What's your call?
    73
    Pat K7KBN
    Semper ubi sub ubi.

  5. #5

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    I would have to say that you need an Elmer first.

    I don't think you have the Lingo down yet.

    A Jeep is a poor ground plane for anything other then 2m / 70 cm FM, just not enough metal beneath the antenna.

    Yes Single Side band gives you about 3 times the distance per a watt compared to FM because the capture ratio is better.

    You probably need to invest in a decent mobile HF all band transceiver - Yaesu / Kenwood / Icom....

    Digital modes will increase your odds of contacts when stationary - while camping, if you use a resonant antenna.

    Might I suggest the HY-Power Antenna Company - 80 meter off center fed antenna.

    http://www.hypowerantenna.com/produc...er-fed-antenna

    Having a good radio is nice, but the antenna does most of the work!

  6. #6

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    "I get the impression that SSB is necessary"

    The problem here is that you've missed the links between past technology and practice with the current practice.

    If the object is distance, then the HF bands are popular simply because of the physics of how radio waves propagate. The frequency is the critical bit. The waves will either hug the earth to go around the globe, or they will travel in straight lines, and either bounce off some of the atmospheric layers, like a pool ball and cushion, or they pass straight through. Time of day, weather conditions, state of the sun spot cycle and other things control this. The transmission mode choice is part physics and part history. Digital modes started with CW, and are still there on HF with the systems many hams and commercial users run - however, they need more effort to put into practice. AM and FM are wasteful of energy, so SSB was a solution. Of course, it's not remotely good quality audio. I didn't really understand your 'voice modulations' question - but I think you meant modes, but sorry if I got it wrong. Modern shorter range communications means FM or digital really. Plenty of people operate on 10m or CB mobile, but everyone soon realises distance e is either very short, unless the band is open and your signals start to bounce back down - which is unreliable. If you are in the desert then the direct ranges which are limited to just a few miles won't be much use, so HF will be your only hope of anything more than maybe 30 miles or so. As said above - antennas become the key factor. Short antennas on a vehicle are always going to be a compromise. They're too short to be efficient radiators. Even those huge ones you see crazy people driving about with are still poor - they'd just not so poor as a simple whip with loading coil. In a desert, a couple of telescopic poles, some guy ropes and then a wire antenna between them might be a better bet - something you can align with a compass to point in the right direction, or maybe even load up the telescopic tubes as a vertical?

    Lots of people use voice processors to maximise their output - full power in the speech peaks means average power is much lower. A processor which is really just a severe compressor makes your signal sound louder than other people. Sounds totally horrible, of course, which puts some listeners off, but does get more information out, per Watt.

    I'm not up on on US licence categories (as here in the UK we don't have any deserts, I guess you are in the US) but if you have HF privileges HF will be your friend - but you will need some kind of antenna that can operate on a number of bands, so you can find one that is open. You start on one, and as it closes, you try somewhere else that's working. My own experience is that any antenna that you can drive with is not really much good as an efficient antenna.

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