Interesting. Is there a canned program to take an autocorrelation of a
wav file? I noticed the signal was wide, so I used the 9.5Khz filter,
though clearly that isn't enough if the signal is 30Khz wide. BTW, it
has an interesting sound with FM demod.

I suppose if I had the ability to digitize at a higher bandwidth, I
could sample my 455Khz IF output and get the whole sweep. I did move
the VCO around a bit and couldn't find a center of the signal.

I've been looking at various high speed digitizers for use as a
pan-adapter. This is the most interesting of the bunch:
http://www.universal-radio.com/catal...rxvr/0014.html


Ron Baker, Pluralitas! wrote:
wrote in message
ups.com...
http://www.lazygranch.com/sound/shortwave/4814usb.wav

I recorded this from the SF Bay area in usb. It looks like bursts of
5Khz modulated at 500hz, then of course gated to wait for an echo.

BTW, I think this is codar.

Yeah, Codar seems likely.
I've put some plots from your recording at alt.binaries.alt.
There are some good echos there.
0.02 seconds corresponds to 6000 km.
I think you will find that the signal is sweeping
down from 4820 to 4790 over about 0.5 seconds,
repeating every second.
It is audible when it passes through the passband
of the receiver.

--
rb