"Cecil Moore" wrote in message
om...
gravity wrote:
and I can send sos with spark gap off a batery without knowing anymore
than that

your engineering skill is formidable.

I don't know much about spark. Was the length of the spark
controllable such that dots and dashes could be differentiated?

click short pause clack = dit
click long pause clack = dah

i think it would be hard to decode vs listening to a modern receiver.

i believe spark gap would be useless in a rescue situation.

Gravity