HOW FAR WILL
YOUR SIGNAL REACH?
Pick your antenna setup, the terrain between you, and your power output. This estimates real-world ground-wave range for the 27–29 MHz band based on horizon geometry, terrain loss, and antenna efficiency.
GO HIGHER
Antenna height matters more than anything else. Every foot of tip height adds usable range on both ends of the link. A 4ft whip mounted on a semi mirror easily doubles what the same whip reaches on a sedan's roof.
SHOP ANTENNAS→TUNE YOUR SWR
A detuned antenna throws power away before it ever leaves the vehicle. An SWR of 3.0 wastes 25% of your output. Check your SWR with a quality meter and our tuning guide — it's the cheapest range upgrade you'll ever make.
SHOP SWR METERS→BETTER ANTENNA
Longer, properly-loaded antennas radiate more efficiently than short rubber ducks or compromised mounts. Moving from a 3 ft antenna to a 5 or 6 ft model with a solid ground plane typically adds 20–30% range on its own. A full-length 102″ whip on a properly grounded mount is still the gold standard at 27 MHz.
TOP-RATED ANTENNAS→MORE POWER
Going from 4W to 100W PEP adds roughly 2× range. Going from 100W to 400W adds another 30%. Each doubling of power adds about 15–25% more range — not double. Match your amp to your antenna, or you're just heating up your coax.
SHOP AMPLIFIERS→GROUND WAVE vs. SKY WAVE — Both Are Real, At The Same Time
GROUND WAVE
What this tool estimates. The signal that travels from your antenna, hugs the curve of the earth, and reaches the other station directly. Predictable, roughly line-of-sight, limited by horizon and terrain.
Ground wave is what you talk to the trucker three miles ahead of you on. It's what lets a base station hear everyone in town. It behaves the same day or night, clear or cloudy — roughly.
SKY WAVE (SKIP)
What this tool does not estimate. 27–29 MHz signals can reflect off the ionosphere when solar conditions are right, coming back down hundreds or thousands of miles away. Unpredictable — depends on time of day, season, and the 11-year solar cycle.
When skip is open you'll hear people on the other side of the country — or the world — while the guy five miles up the road can't hear you. This tool ignores skip because it's not something you can plan around.