gudmundur ) writes:

I used to love to drive the woodpecker crazy. It was easy to chase it
out of the ham bands.

The Woodpecker changed frequency all the time anyway, whether anyone tried
to interfere with it or not. It was part of their operational plan. And
the pulses carried a PSK coded pattern to make it easier to recover the
returned echoes, sorting them out of the interference. I doubt very much
that anyone could really interfere with them when they operated.

.... Martin VE3OAT