by raceamerica » Tue May 29, 2018 2:06 pm
Since RF signals are pretty much invisible, we all need a little help to maximize signal strength. Knowing the environment cell phones operate in, cell phone company had to develop solutions so antennas are positioned very high on towers and in locations where signal will be blocked by other objects. Same rules apply to any wireless setup, we just need more practical solutions than lug a 50 foot tower around.
Remember, every setup is different with different environmental obstacles. In most cases, the wireless setup will just work but as distances increase and race spaces are invaded with structures, here are a few simple and hopefully logical things to look for:
- Lots of race tracks have tall chain link fences along the race track. To RF, these chain link fences are big solid metal reflectors. Signals will bounce off and the receiver will receive multiple reflections of the same signal confusing the receiver. Best suggestion here is to mount antennas above the top of the chain link fence to minimize reflections.
- Large structures and buildings are often at race facilities. To RF these structures act as big reflectors or deflectors. Signals will bounce off in the direction of the receiver or signal will be deflected away from the receiver causing a low received signal. Best suggestion is to position antennas away from these structures or select the racing area farthest from these structures to minimize their effects.
- Many parking lots and race surfaces, especially airports, have large amounts of steel rebar as reinforcement. Placing the T-Links on the ground cause the steel rebar to act as large antennas and ground out RF signals. Best suggestion here is to leave the T-Link on the ground and raise the antenna itself using coaxial cable. The antenna can easily be positioned 6 feet above ground level for short distance wireless communications or 10 feet and greater for longer distances.
- Adding High Gain Yagi antennas or High Gain Flat Panel antennas help focus the signal in the direction of the receiver reducing the amount of signal from being reflected in the direction of the receiver.
- Use the RF Integrity test available with many RaceAmerica wireless systems. This helps us humans 'see' the RF signal. When the RF Integrity bounces around, it is an indication of reflected signals received. When the RF Integrity is low, it indicates the RF signal is being absorbed or deflected by large metal objects.
Remember the signal between two antennas is like placing a football between antennas. The closer to the ground the antennas are positioned, the more it cuts off the football and the total amount of signal.
Hope this explanation helps visualize what the RF signal 'looks' like.