JIMMIE wrote:
The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal.

Radio amateurs do this all the time. In most countries, for it to be
legal you need a radio amateur license.

Today it actually is not very difficult to receive moon bounce reflections,
because we can make very sensitive receivers and detect signals that are
below the noise, using a computer.

However, to do that you need to transmit a signal at a very stable
frequency, so that you know beforehand what will be coming back.
A microwave oven magnetron cannot really do that. It transmits a
big blob of RF at a woblling output frequency, rather than a well
defined frequency.

You also don't need that power, really. It is better to spend your
effort on a good antenna, because it helps both during transmit and
during receive, doubling the outcome of your effort.