Jake Brodsky ) writes:
Ron J wrote:
So I was doing some reading and one article mentioned that a group
mounted an FM transmitter on a hot air balloon. I was also researching
on the methods used by the FCC to measured field strengths. So how does
one go about measuring field strength levels if a company somewhere,
somehow, sometime decides to mount their transmitter on a hot air
balloon to avoid building a tower?

Because the communications are likely to be line of sight, you could use
inverse square law equations to predict the signal strength.

I was reading the problem as "since the balloon is moving, how can
you even fix on a pattern"

A lot of that isn't so much about field strength as pattern. They want
that controlled. And that's arrangeable when the antenna is fixed.

But if the antenna is moving about, then the pattern will change as
it moves, so you can't guarantee that it won't interfere with that
station in the next town over, while a fixed antenna would allow some
sort of directionality to provide a shadow in that direction.

Reminds me of people using 2M FM in the early seventies, from
small airplanes. They had no problem with a handie-talkie's low
power output, they had all kinds of problems with not being
able to control it so transmitting on a popular frequency would
trigger a bunch of repeaters at one time.


Michael VE2BVW