I am doing some temporary FM broadcasting for car events such as COVID-safe car parades and drive-in movies. The terrain is horrible, urban areas with lots of buildings. The cars snake around a city, with the transmit car in the middle.
Understandably, there are not many purpose-built, car-mounted FM radio transmission antennas.
- I have a 1/4λ Pulse Larsen PulseLarsen NMOQ88C on a 5" NMO mag mount.(tuned by instructions) It works okay, but I wonder if there are better options.
- It seems there aren't any 5/8λ antennas with NMO mounts in this range, would it be possible to modify a 102" CB Whip into a 5/8λ antenna at 88mhz? Can I use a base loaded coil from a 144-174MHz NMO 5/8λ system with a longer whip?
- Is a 1/2λ worth exploring?
I am transmitting with 30W. I have no antenna analyzer nor an SWR meter. I am most interested in what I realize is mostly impossible, better NLOS (Non line-of-sight) transmission so cars can continue to hear after they have turned a corner.
Is the 1/4λ as good as it gets for my application?