I currently own a 7 Watt Frequency Modulation (FM) transmitter that I purchased from eBay some years ago.
We are planning a drive-in cinema setup where the transmitter will be placed 5 meters above ground at this location.
A technician I interacted with informs me that considering the number of cars that might show up, about 300, the transmitter signal will severaly degrade as the cars will pretty much cause interference and signal power will have to be boosted.
Is there a formula / mathematical calculation that can help me determine how many cars can tune into the assigned frequency without experiencing a drop in audio quality?? Or a formula to help determine how much transmission power is needed?