When an experienced radio operator is asked this question, the first thing they may tell you is “well, it depends”. While anything is possible, there are a lot of factors into that that may dictate the answer to that question. Some of the factors are 100% out of our control like the weather and the sun. The sun? Yes, the sun charges the atmosphere that allows our signals to bounce to reach the far reaches of the globe, it can also cause it so nothing goes out. (You learn a LOT more as you study).

I like to call VHF/UHF bands the local bands. You can maybe talk to someone the next town over, but likely not someone much further than that. The range varies based on the radio the use and if you use a repeater and the repeaters height. “It depends”. However, typically this is fairly reliable where you can talk to someone every day within the range that you determine is your max. VHF/UHF bands are line of sight, meaning that the radio signals needs to see the other antenna to work. if you are on a tall hill, your range is longer that if you are in a valley.

HF is what most imaging ham radio is about. That is where you can talk to the world on a radio. However, the sun plays a huge factor in how well you can talk to others. It's a game of Russian Roulette on who you can talk to today, but like the experiences operator says, “well, it depends”. Here is what I can tell you from my experience, I'm on a net where the goal is to make contacts with other hams around the country and around the world for awards. Those of us regulars know who we can always contact if we are in a pinch and you know how bad it is if you can't hear them. So, in theory, you can talk to someone on the opposite side of the world from you, but if you are relying on checking in on that person in a disaster, there is no promises that you can always make it, at least without spending some big money on big equipment and a prayer that the sun cooperated.