Communications Technology

The Comms Plan (part2)

We’ve talked a bit about the differences between HF and VHF, and we know that HF signals travel further than VHF, but why do they? One of the layers of our atmosphere is the Ionosphere, made up of charged ionized particles, our HF radio signals will often hit the Ionosphere, and bounce back towards Earth.

A radio wave can bounce several times, each extending it’s range further, at VHF and UHF frequencies, the radio signals penetrate the Ionosphere instead of bouncing off off it, but there are ways of extending VHF and UHF signals, we’ll touch on that subject a bit later.
As I discussed earlier, if your group is largely local, you can limit your communications to handheld VHF/UHF radios, but if you have people in other states you’re best chances for dependable comms will be happening via HF.
What are the trade-offs?

  • HF radio equipment is typically more expensive, and not as portable as VHF/UHF gear)
  • HF antenna requirements are similarly not as portable, and will take time to erect/assemble, VHF/UHF antennas are often just inches long and integrated to the radio itself.
  • HF gear has higher power requirements, VHF/UHF often run on inexpensive ni-cad rechargeable batteries.
  • HF gear typically has far greater dependable ranged communications than VHF/UHF
  • VHF/UHF gear depends on repeaters to extend their typically short ranged comms, HF gear does not require repeaters to extend range.

What are the takeaways here? VHF/UHF is lighter and more compact (typically) at the expense of shorter range communications, HF gear can communicate over far greater areas, however you’ll be paying quite a bit more for HF gear, and you’ll need to bring an antenna and assemble it before communicating.
In either scenario, I believe there is ALWAYS a valid case for employing VHF/UHF radios, here why: Nearly all Amateur Radio Clubs operate a repeater, this can best be described as a high-powered middleman that received your weak VHF/UHF signal, and then amplifies that signal, and retransmits it at a slightly different frequency, in realtime. Repeaters are often located at the higher elevation locations in your area to ensure the signals are broadcast with maximum effectiveness. Some years back we had a very bad ice storm in Kentucky, most areas lost power as the trees were falling over from all of the ice, taking power lines across the state with them. Some areas were without electricity for nearly a month.Many of the Radio Clubs had volunteers driving to their repeater locations and keeping the generators running and fueled, they may have lost their normal power, but the backup generators kept the repeaters operational, and many Amateur Radio Operators were able to communicate their status, and radio requests for assistance from quite a distance because their VHF/UHF gear was battery operated, and the repeater was still running. Radio Clubs place a high value on their repeaters remaining in service regardless of the situation.
Again, even if it’s just monitoring traffic, you’ll be hearing whats happening closer to you while monitoring the VHF/UHF bands, particularly the repeaters. If you hear someone on VHF say “We lost power here.” you’ll know someone has lost power, typically, within 35 miles of you. If you hear the same message on HF, say 80 meters, that guy that lost power might be a thousand miles away.
There is always a valid use case for VHF/UHF in my opinion, if I could only have one band to base my entire communications plan from, it would be VHF, 2 meters. The radios are very affordable, and particularly if you are near any type of city, there will usually be repeaters available to extend your range.
All that being said, my existing Communications Plan includes HF, VHF/UHF, and FRS. I’ve previously posted about CB (I have multiple mobile CB’s), FRS (see my previous post regarding FRS and the Icom IC-4088A) and the glue that keeps it all together is an all-band Yaesu FT817 which can communicate with all of the radios I’ve listed.

The FT-817 is a small, mobile radio than can operate off of an internal ni-cad battery pack. It’s a low powered (5 watts) HF/VHF/UHF rig that can fit in a jacket pocket.
I realize that not everyone is willing to invest in a larger collection of radio equipment like this, but something to keep in mind is that I use a good portion of my radios, regularly as I’m a licensed Amateur Radio Operator, that these radios can also fill a vital role in my preps is an added bonus.

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