Hi,
I'm playing around with some 433MHz transmitter and receiver pairs.
Ideally I would like the transmitter to transmit in a narrow
directional beam, but I'm new to the art of radio waves and antenna
design, so I was wondering if you guys would be able to help me with
my project. I've read about a Yagi design for the antenna, I know it
receives from one direction only, but does it transmit in just one
direction too?

I thought I'd be able to basically stick the transmitter antenna in a
tube, sealed at one end, line either the inside or outside of the tube
with tin foil (or both) and it would transmit in whatever direction
the open end was facing. So far my tests haven't been too conclusive
but could that be poor setup on my part or is the idea fundamentally
flawed?

Many thanks for your time,

Simon.