Site Survey Guidelines for Trango Analog Video Installations
How to conduct a site survey to avoid RF interference
Before deploying your new analog wireless video transmission system, you should consider conducting a formal site survey. When choosing your wireless surveillance system and transmitter locations an important factor to consider is whether there are any other sources of RF in the area. A site survey should be performed prior to any new wireless installation, and is particularly important in industrial areas and other congested places such as metropolitan areas.
One of the first things that you should do is to conduct a visual inspection of the installation site(s). Look for other RF transmitters, antennas, and radios that may potentially interfere with your intended wireless paths. When choosing locations for your receivers, it is important to avoid being near any high-power radio frequency (RF) transmitters.
Another commonly overlooked source of interference in the 2.4 GHz ISM band is the conventional microwave oven. It is important that the Eagle PLUS 2.4 GHz receivers and transmitters be mounted as far away from microwave ovens as possible. If that is not feasible, you may need to consider using a different frequency, such as the 5.8 GHz transmitter, Falcon PLUS. You may also consider using a digital video system, or shielding the microwave oven externally.
If you have selected a location without any other visible RF radios, you probably will not have any problems caused by interference. However, it is always best to conduct on-site preliminary RF testing before you perform the permanent installation. On-site preliminary testing can reveal potential problems and allow you to troubleshoot and avoid larger complications that can compound during or after the permanent installation. If there are visible RF radios at your installation site, you should perform one of the following checks to help ensure that you do not experience complications during installation.
1. Spectrum Analyzer: If you have access to a spectrum analyzer, you can use it to perform a site survey, which can provide you with accurate information about the frequencies and power levels of RF radios at your site. This is only recommended for customers who have experience with RF and have test equipment that is readily available.
2. Built-in RSSI: The best approach for most users will be to take a receiver to the installation site. You will want to use the same type of system and antenna that you are planning to use for that application. When you are on site, power the system up with the antenna attached. Place the receiver in RSSI mode by pressing and holding the toggle/RSSI switch until all LEDs are lit. After you release the switch, the receiver will then be in RSSI mode, and the LEDs will indicate the received signal strength.
It is important to check RSSI with the transmitter turned off as well as with it turned on. Checking RSSI when your transmitter is off will give you an indication of whether there are any existing interferring RF signals in the area that may interfere with yours. If the RSSI is indicating a received signal strength of two LEDs or less there should not be a problem. If it indicates more than two lite LEDs, then this may be a potential interference problem and you should try to locate the source. If you can locate source try to isolate your receiver from the foreign signal as much as possible. If at all possible, the complete system should be tested in place before it is installed wherever there is a chance of interference.