Part of our Building Your First Ham Radio Station guide.
A lot of hams come from a military background, and even for those who did not, military radio practice is a genuinely useful lens for understanding propagation and antenna choices, because the priorities are so clearly defined: reliability, range, and the ability to keep working under difficult conditions. Here is a broad overview of what tends to get used, and why.
HF for long range and NVIS coverage
HF, roughly 2 to 30 MHz, remains the backbone for beyond line of sight communication when satellite links are unavailable, jammed, or simply not worth relying on for every mission. For regional coverage out to a few hundred miles, a technique called NVIS, or near vertical incidence skywave, sends the signal almost straight up into the ionosphere so it comes back down in a wide circle around the transmitter, filling in the gaps that line of sight radios cannot reach over hills and terrain. NVIS antennas are typically simple horizontal dipoles or inverted Vs mounted low to the ground, often less than a quarter wavelength up, since a low horizontal wire radiates most strongly straight overhead, which is exactly the pattern NVIS needs.
For longer haul, strategic HF links, higher and more directional antennas come into play, sometimes log periodic arrays at fixed installations, to concentrate energy toward a specific distant station rather than spraying it in every direction.
VHF and UHF for tactical, line of sight work
Most day to day tactical traffic, unit to unit coordination on the ground, moves over VHF and UHF, where line of sight range is traded for smaller antennas, higher data rates, and reliable, predictable coverage. The SINCGARS family of radios operates in the 30 to 88 MHz VHF FM range and is built around frequency hopping, jumping between channels many times per second, which makes the signal far more resistant to jamming and eavesdropping than a fixed frequency system. On the antenna side, this usually means straightforward vertical whip antennas on vehicles and manpack radios, simple, rugged, and omnidirectional, exactly what you want when you cannot predict which direction the next call will come from.
At fixed command posts, broadband antennas like the OE-254, a vertically polarized biconical style antenna covering the 30 to 88 MHz range, are common for base station VHF work, since they give solid all around coverage without needing to be tuned to a specific channel.
Common radio families
- AN/PRC-152 and AN/PRC-148 (MBITR): handheld multiband radios covering VHF and UHF, widely used for small unit and personal tactical communication.
- AN/PRC-117G: a heavier manpack radio that spans VHF and UHF and adds satellite communication capability, used as a bridge between line of sight tactical traffic and beyond line of sight reach back.
- AN/PRC-150 and similar HF manpack sets: used for longer range and NVIS style communication when VHF and UHF line of sight is not enough.
- SINCGARS mounted radios (the AN/VRC family): the vehicle mounted VHF backbone for ground unit coordination, built around frequency hopping for security.
Satellite for reach that terrain cannot block
When line of sight VHF and UHF cannot reach far enough, and HF conditions are not favorable or fast enough for the data involved, UHF satellite communication systems fill the gap, giving reliable coverage regardless of terrain at the cost of needing a functioning satellite constellation and often a directional or steerable antenna.
None of this is exotic compared to amateur radio. It is the same tradeoffs hams deal with between HF skip, VHF and UHF line of sight, and antenna directivity versus coverage, just applied with a much bigger budget and a much stronger emphasis on the link working every single time.