Cheap thin cable can result in even the best antenna being worse than useless. Signal losses are frequency dependent, the losses becoming higher as the frequency increases. It is not unusual to experience 5 times as much signal loss at 6 GHz than at WiFi's 2.4 GHz. Installing a 15Db gain antenna and running cheap antenna cable can result in cable loss of twice your antenna gain. Don't bother buying a good antenna if you are running cheap cable. Losses can be reduced by increasing the diameter of the cable. A cable with twice the diameter will have half the signal effect resistance loss. Assuming cable quality is equal, the larger cable would halve the dB/meter loss. In designing a system, consider not only the loss in the cable, but also the loss in the connectors. Cheap connectors give you as much loss as cheap cable. On a final note, poorly made LMR600 "type" cable can have a greater signal loss than good LMR400.
This is Top Quality LMR400 50 Ohm Cable. All common Radio Frequency (RF) devices CB, Ham, WiFi, Packet Radio, etc. are to be used with 50 Ohm cables and connectors. 75 Ohm cables and connectors are designed for low frequency signals like Video or Cable TV and are unsuitable for most all RF installations. Each type of coaxial cable has a characteristic impedance (resistance) depending on its dimensions and construction, which is the ratio of the voltage to the current in the cable. In order to prevent reflections at the destination end of the cable from causing standing waves. The equipment "appears" electrically similar to a continuation of the cable, preventing reflections that cause signal degradation.
In high quality cable the dimensions and spacing of the conductors are uniform. Any abrupt change in the spacing of the two conductors along the cable tends to reflect radio frequency power back toward the source, causing a condition called standing waves. This acts as a bottleneck, reducing the amount and quality of the transmitted power. To hold the shield at a uniform distance from the central conductor, the space between the two is filled with a plastic dielectric designed to maintain the proper spacing between conductor and shielding to assure maximum signal transmission and lowest loss. Manufacturers specify a minimum bend radius, to prevent kinks that would cause reflections. You should allow three inches of cable to make a 90 degree turn in your runs without causing signal loss. The connectors used with the coax must also hold the correct spacing through the body of the connector to avoid signal loss. The transmission of energy in the line occurs totally through the dielectric inside the cable between the conductors. This cable can be bent and moderately twisted without negative effects, and can be strapped to conductive supports without inducing signal interference.
LMR-400 cable is designed for outdoor applications, can be direct buried, and the outer jacket resists ultraviolet light and oxidation. There is no environmental restriction on use for indoor installations. We also have LMR400 cable for indoor/outdoor installs certified as fire resistant as required by the Pennsylvania Bureau of Mines.