How can a Tech reach out 80 miles with voice?

Discussion in 'On-Air Operations - Q&A' started by KE0KDQ, Aug 3, 2018.

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  1. KE0KDQ

    KE0KDQ Ham Member QRZ Page

    Ready for a tough nut to crack?

    I have a friend 80 miles away as the crow flies. I'd like to be able to talk directly to him without using repeaters or cell phones :)

    If we're both Techs and we need to use voice to communicate, is my best bet 10 M SSB? I know there are better options like "get your General tickets," "wait for the sun to start cooperating," or "use CW and 1500 W" but let's say our limitations are Tech tickets and voice comms without repeaters.

    Any advice other than pray?
    KE0KDQ
     
  2. KL1T

    KL1T Ham Member QRZ Page

    Height and a yagi are your friends.
    There are many places that 80 miles on 2m wouldn't be a problem with a 50w mobile rig. You will need height at one or both ends with no hills of any kind blocking the path between you.
     
    K9ASE likes this.
  3. WG7X

    WG7X Premium Subscriber QRZ Page

    It's not tough at all.

    You both need one of the small four element antennas from any good manufacturer. I used a four element Cushcraft. With yagis on both ends and some height, 20-30 feet is usually achievable, the path should work. Two meter SSB is preferable to FM, but both should do the trick, with SSB being far superior to FM for this kind of situation.

    If the path is still too tough, more height or really big antennas...
     
    KB4QAA likes this.
  4. N2EY

    N2EY Ham Member QRZ Page

    What is the path between you locations like? Flat? If so, as others have pointed out, it's just a matter of a good Yagi at a sufficient height, with a decent receiver and maybe a bit of power.
     
  5. AI3V

    AI3V Ham Member QRZ Page

    You in Kansas Toto? :)


    Vhf is what you want, with as long a Yagi-Uda on each end as you can get up.

    Note: gain comes from boomlength NOT the number of elements, don't be fooled!

    And I'd go for a hundred watts or so.

    SSB is better than fm.

    Try and borrow some gear, you probably can get buy with less.

    You will be using a mode called troposcatter, a line of sight path is not necessary, and modest hills in between will have little effect.

    Rege
     
  6. N8AFT

    N8AFT Subscriber QRZ Page

    Learn code!
    Do 80+ miles with ease as CW propagates well even with very low power.
    Your Tech ticket entitles you to a vast amount of HF frequency when you go CW.
    Something I hope you will consider. Besides anyone can use a mic, it takes zero talent or effort.

    Learn Morse
    Do CW
    73
     
  7. K3UJ

    K3UJ Ham Member QRZ Page

    6M should work too. Same type of antenna setup and mode.
     
  8. VK3YE

    VK3YE Ham Member QRZ Page

    Provided there's not too many obtructions, I'd also pick 2m SSB.

    >20w to a 4 or 6 element yagi should do it. Some examples (with lower power and smaller antennas) are below.

    http://home.alphalink.com.au/~parkerp/gateway/vhfssb.htm

    There are websites where you can put in your location and the other stations and it will show the path between them.
     
  9. K6CLS

    K6CLS Ham Member QRZ Page

    I easily get ~85 miles on 432.1MHz. that's with my homemade 13el WA5VJB Cheap Yagi at about 20' (temporary pole), 30w, although 100w is better. Other station's yagi is quite high, perhaps 75 feet. so yeah, get some altitude.

    SSB is the best but I think FM would work. I believe lower bands would work better, so try 2m as you planned. Although, 222MHz has some interesting properties such as much quieter than 2m and perhaps better propagation, however, SSB rigs are hard to come by and any power over 25W or so is not $cheap.

    check this out:

    https://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf

    build your own for $cheap! it is easy and fun. the document has plans for 2m through 23cm. I also built the 5el for 2m, it works great!
     
  10. W2WDX

    W2WDX Ham Member QRZ Page

    How? Well many ways actually.

    6m can be a fun band when sporadic-e and other prorogation is working. Hundreds of miles is not uncommon. SSB USB is the most common mode for voice. Digital modes as well. Not to difficult to set-up station wise. Simple dipoles and a good transceiver can get you out there fairly well.

    2m is a challenge since your primarily using thermal layers in the atmosphere to act as a wave-guide for your signals; the signal getting trapped and bouncing through the thermal gap. Hundreds of miles is also common when this type temperature inversion exists. It's called Troposheric Ducting. BTW, if you want to really get distance, how about bouncing signals off the moon and back to earth. Yeah for real ... It's called EME Moon Bounce, but that takes a very big antenna array and lotsa power. But it is done often by many; rarely with voice though.

    70cm is tougher still and really depends on the antenna you have and your power. High-gain antennas are however relatively small and 20el+ Yagis are not uncommon.

    Now all of this is very dependent on how well you set-up your station and antenna system. There are many prerequisites; like first understanding losses at VHF and UHF frequencies and that loss has an equal effect on transmits as well as receive. Loss is not just about losing power, it's about not hearing anything but noise. I would argue many hams who do not know or understand this single issue are the same ones who complain they do not hear any activity on certain bands. It's out there ... it's just the signals are very weak, so getting your losses low and signal gain high (both for transmit and receive) are vitally important. High-grade low-loss coax is essential; such as LMR-400 as a minimum. High-gain antennas, placed as high as possible are crucial. Mast mounted preamplifiers are very useful (if of good quality) and can make all the difference. And never underestimate the need for good station grounding, if for anything reducing noise level on receive. Notice I didn't mention linear amplifiers. This is because as a rule on VHF/UHF weal signal work, if it improves receive it will follow it does the same for transmit. Besides, what good is a 2kw 2m amplifier if you can't hear diddly.

    Now out where you are (KC area) it's not too hilly and I suspect with a good Yagi and some height you should have no problem on 2m SSB with your buddy. But trust me ... once you get that working (and you should be able too quite easily), you should really try to explore the stuff I mentioned above. I did a lot of DX as a Tech on VHF, but there is a learning curve for maximum performance; as there is for most things worth doing!
     
    Last edited: Aug 4, 2018

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