Hello. I am completely unfamiliar with 2-way radios, so I am hoping to get some guidance here. For background, I will say that I am relatively expert in cybersecurity. As a result, I am concerned that all of us may be plunged into an emergency environment with no digital communications of any kind possible for an extended period of time. This is probably not likely, but I am trying to come up with a family emergency communication plan nonetheless. Assuming that HAM radios (or similar) will still work during a digital blackout, e.g. no Internet, no cell phones, no voice over IP, etc. is it possible for someone in, say, New Jersey to communicate with a shortwave operator who could relay a message to me in Ohio? Is that possible. If so, what equipment would I need? Are there better ways to have such communication between two people 500 miles apart? Thanks
Welcome to the forum. Yes, 500 miles is doable via HF radio. In some cases it may be doable via VHF/UHF radio as well but it is dependent on existing infrastructure.
500 miles is about the limit of NVIS (Near Vertical Incidnece Skywave) which is a setup popularized by the US military during the Vietnam war. It consists of a low to the ground dipole antenna (10 ft or less) and essentially uses uses the backdrop of the earth to push signal upwards which then reflects off the ionosphere and back down (thus the limitation in distance). It is quite reliable on 40m, 80m and 160m though and typically doesn’t take a ton of power (100W or less). Of course, other antennas setups will function just as well.
For VHF/UHF there are many analog link systems out there which piggy back from site to site only requiring the sites have power. This takes some research to get right. Many of the newer analog link systems use an Astrisk based module to transport audio over SIP. This transport can be either private microwave links or the internet (though you are trying to avoid internet), doesn’t matter as long as it is a L2/L3 network. Another similar option is digital radio modes such as DMR which still requires some form of IP network.
There are also such systems called packet radio networks. These use slow speed data (300 bps for HF, 1200-9600 bps for VHF/UHF) which can function similarly to a basic IP L2 network to pass messages and emails. There are even some protocol stacks to merge the IP network with the packet network called AX.25 but much of this still requires some form of infrastructure somewhere.
To make HF practical you will need at least a general license. For VHF/UHF a technician license will suffice. You may also be interested in systems such as HamWan and Winlink for data transport.