Written by Stephen Froneman.
Here are some of the reasons you might be experiencing a worse performance after connecting an external antenna:
Internal / External Antenna Selection: Some routers have an option to select between an ‘Internal’ and the ‘External’ antenna. When connecting an external antenna, it is important to check this option is set correctly in the GUI settings. If this option is selected incorrectly, then the router will not gain any benefit from the external antenna. Not all routers have this option, so please check the router manual.
Incorrect impedance coax cable: When the incorrect impedance specification is used, this will cause a mismatch between the antenna and the radio of the router, which in turn may negatively affect the wireless system performance. It is important to ensure that the same impedance is used for the whole system e.g. using a 50 Ohm antenna with a 50 Ohm coaxial cable, with the 50 Ohm router or radio is necessary.
Water proofing connectors: Please also check that the connectors are protected from water ingress. Connectors that are exposed to water, even moisture, are known to suck water into the coax cable as the temperature fluctuations cause the cable to expand and contract through the day. The connectors therefore need to be sealed properly (or installed in a waterproof area).
Antenna alignment: When using a uni-directional antenna (aka directional antenna), then the alignment to the best base station is of utmost importance. Please see the FAQ titled: “How To Orientate A Directional LTE Antenna During Installation?” for more information.
Installation obstructions: Installing an antenna with obstructions (trees, buildings, etc.) very near to the antenna may cause the antenna signal to be obstructed. Although Line-of-Sight (LOS) is not always needed between the base station and the customer antenna, it is best to install the antenna such that it benefits from the least obstructions possible. For more information, see our webinar titled Factors affecting your #RF experience on this topic.
RPSMA connectors: An RPSMA connector is often mistaken for an SMA connector, and visa versa. (RPSMA connectors are normally reserved for Wi-Fi applications). We occasionally find customers connecting an RPSMA to an SMA connector; these connectors are partially compatible from a mechanical perspective, but they are not compatible electrically. Please ensure that the connectors are checked for this easy mistake. For more information, see below:
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