HF versus VHF/UHF

Posted: 09/23/2015 in Communications

Guys, lots of questions coming in regarding HF vs. UHF/VHF radios and antennas. Let’s flog that deceased equine a little longer; If you get your Amateur license at the Technician level, you won’t have to ask these questions any longer.

VHF/UHF radios work on the frequency bands that inherently use short/very short antennas, plus, they are usually very small, light weight, easy to operate, and run off of batteries. What’s not to like! I think this is why most folks initially purchase these radios as inter-squad level comms.

And while they do have those advantages, one of their major disadvantages is that they usually only work when they are in unobstructed view (line-of-sight) of one another. Put most any obstruction between the two (an area known as the First Fresnel Zone) and you have no or very poor comms. The obstruction could be just about anything; a hill/mountain, forest, large buildings, moving vehicles, or any combination of these things. In addition, factors such as power output and receiver sensitivity are also in play.

So, how do we get around (or over) those obstructions? Use a repeater mounted above the obstruction. Then you are relying on someone Else’s infrastructure. And if you do get comms over the mountain to your buddy in the next valley, how do you get to the valley beyond him? Another repeater.

Here is the link for a well put together article on comms for the beginner from INFORMOPS. Take a look toward the end of the article for some visual descriptions of the challenges regarding VHF/UHF comms. I should have had his blog listed as one of my favorites a while back, my mistake. HT to PSYOP Soldier for reminding me.

https://informops.wordpress.com/comms-101/

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Comments
  1. For those wanting a good VHF/UHF mobile, the Yaesu 2900R is on sale, shipped, for $139/95 at http://www.hamradio.com until 30 September…there’s still time to save some money on it if you or someone you know is in the market…

    • FrozenPatriot says:

      The 2900R is single band (VHF) at 2m only…

      • PSYOP Soldier says:

        FrozenPatriot…Correct, 2m only, perfect for local/semi regional comms using simplex (radio to radio and/or HT’s) or duplex via repeaters..Power from 5w-75w and bombproof…A must have for basic local comms too….Connect to small agm battery, sling a ladder line j-pole in a tree, or a Yagi, and shazam, comms, as most every ham operator i know of, has a 2m rig…..Not to mention, NOAA weather alerts too, very nice to have in bag of tricks…saved my, and my fellow campers butts as massive, unexpected thunderstorms with air to ground lightning rolled in and i was able to give em a heads up..

        I have a kenwood 281 2m in my shack, arrow j-pole in attic, mounted to roof truss with flag pole kit, and i can hit the Mt Mitchell 2m repeater, almost 100 miles from my home…My other 281 is for my field box, and can talk to wifey while i am in WNC stalkin trout, and she is at home to let her know i am ok..I can also use the kenwood tmv71 2m/70cm rig in my suv to hit repeaters or simplex, and communicate too…A 2m rig is very versatile and a must have..

  2. Doug says:

    Now that’s information a radio squid like me can sink his teeth into. It may be obvious to you but to me it is just what I needed to hear.
    When your starting out from zero, there is such an embarrassment of riches of information from people who have years and decades of experience, the important basics and little details they take for granted are lost in the telling.
    What you wrote above Dan Morgan right there is a keen principle of KISS.
    Thanks, appreciate you.

  3. […] Get your General license and get on the air. […]

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