In article , wrote:
In article ffd0d3c9-18d9-4b7b-95dc-

I think that echo you hear is the one that results from the terrestrial
pulse you just heard, and not 1 or 2 back. My guess is that the leading
edge of the reflected pulse arrives approx. 2.5 seconds after it leaves
and the same for the trailing edge of the pulse. That means if you look
at entire 5 second time line, at 0 seconds the earth pulse starts and at
2 seconds it ends. At 2.5 seconds the beginning part of the echo pulse
arrives and at 4.5 seconds (2.5 seconds after the terrestrial pulse
ended) the end of the echo pulse arrives. There is always 2.5 seconds
between any reference point on the timeline of the sent pulse to the
corresponding point on the timeline of the return pulse. One complete
cycle of send/receive should be approximately 4.5 seconds. I think that
is why they selected 5 seconds between sending 2 second pulses. At
least that is the way I view it. I am open to other views.


On the first transmission, (Jan 19, 05:00 UTC), I tried using an
oscilloscope to see if I could see the echo. It was a 4 second cycle
with 2 seconds on and 2 off. (Which made syncing the scope (with a 5
second sweep) a real pain. The next pulse was going when the first one
ended, triggering it again).

Anyway, with the narrowest (2 kHz) bandwidth on my old R-1000, it
just didn't cut it. When the outgoing signal was S9+10 (in Seattle)
I thought I might have heard an echo or two, but just couldn't be
sure.

What bandwidth were you successful listeners using?

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)