Too many buy a $1000 radio, a $600 antenna, and a $250 rotor, then use 50¢/ft coax. Do not fall into that trap.
HF-Low power; A light weight cable will work fine such as 50-ohm RG-8x or RG-58 and 75-ohm RG-59 or RG-11, the latter being inexpensive, but most vendors do not carry it. (excess TV cable). The loss factor is negligible.
HF-High power; RG-8 or LMR 400 will be desirable. Lower loss and dissipates the heat. Usually there will be at least two braids (one keeps power in and the other shields RF out) The tradeoff is price.
VHF/UHF; Always go with the lower loss cable. For mobile applications though (because of the noticeably short run) the smaller cables are easier to install and because of the noticeably short run, loss is not a factor.
POTA-Lightweight coax preferrable. You will want something very flexible.
Special Applications—If burying, make sure the jacket is marked ‘bury or buryflex.” If not, water will eventually cause problems. If exposed to high heat (like southern climates) make sure you have a “UV” jacket to protect against the sunlight to reduce premature deterioration.
RG-213 can be used in almost any application. (RG, is an old military term for “Radio Grade.” Only applies to RG-213 in today’s terms.
If there is a high mismatch especially when using open wire, window line, or other high impedance (often called “balanced”) feedline, a balun may be necessary. Baluns (and connectors) are whole topics in themselves.
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