Michael Black wrote:

On Mon, 22 May 2017, analogdial wrote:

Vassilis Spiliopoulos wrote:


Yes indeed sabotage.I have experience in electronics.

If you're on a strict budget, a homebrew spark gap transmitter would be
affordable.

Well a buzzer is simpler, and does about the same thing.

Michael

I used a double pole relay. The budget constrained radio pirate must
make do with what's available. Tuned circuits and antennas can be
scrounged from construction debris.

But a buzzer is good. A doorbell is problematic.