SureCall | 48346 Milmont Drive, Fremont CA 94538 | 1-888-365-6283 | [email protected]
10
Planning
If you are using a Yagi exterior antenna, you should normally aim it away from all interior antennas
regardless of separation to prevent oscillation.
3.5 Calculating Signal Strength
You can calculate the number of antennas you will need using the following parameters (in dB):
•
Outside signal level (OSL): This is the signal strength at the exterior antenna location and will
always be a negative number that will usually fall between -50 and -100 dBm. Calls will drop at
levels of about -100 dB and lower. A system installed in an area where the signal is -85 or worse
will require some detailed engineering to achieve an acceptable solution.
•
Outside antenna gain (OAG): This is the signal boost provided by the exterior antenna and is
always a positive number with SureCall antennas.
CAUTION: SIGNAL OSCILLATION CAN CAUSE RADIO
INTERFERENCE WITH CELLULAR TOWERS AND RE
-
SULT IN CIVIL AND/OR CRIMINAL PENALTIES.
SC-288W omni +3
OAG Gain
