[amsat-bb] "listening" to 9k6

["Lars Mortensen" <labmo@xxxxxxxxxxxxx>]

Hi amsat friends
Lately, there has been a lot of talk about how to rekognize a 9k6
signal.
It has allready been said, that it's difficult to hear, it's actually
just a slight
change in the "character" of the noise,.... Easy to hear if u've tried
it before, but
otherwise close to impossible.

But..... There is hope, IF u have an oscilloscope (doesn't have to be a
fancy one) 
u simply connect the scope to the 9k6 output (if u have one) or to an
early stage of
audio (discriminator out, detector out or similar).

By carefully adjusting the "trigger" knob, u can get something called an
"eye-pattern"
which will look like several sinewaves overlapping eachother.
The distance (in case of 9k6) between 2 "tops" (or bottoms) will be
approx. 0.1 ms
(which is typically one square on ur scope, if u set ur time base to 0.1
ms)

I have used this method many times, but unfortunately i cannot take a
picture right
now, as I am in the middle of changing QTH.


Good luck, 73 de OZ4UI/Lars

----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org