R: [amsat-bb] AO-7 70cm tlm

["i8cvs" <domenico.i8cvs@xxxxxx>]

----- Original Message -----
From: Geoff <vk2tfg@ozemail.com.au>
To: amsat-bb <amsat-bb@AMSAT.Org>
Sent: Monday, July 01, 2002 1:01 AM
Subject: [amsat-bb] AO-7 70cm tlm


> Hi Guys,
>   here are some observations on the AO-7 pass just gone (LOS 22:49:37 @
> 37.89S 144.617E).
> The bird was transmitting weak CW telemetry on 70cm. The transmitted
> frequency was about 7 or 8 kHz high (f0=435.1075). Using the CWN filter
> on my TS790A I was able to resolve the beacon into 2 signals about 1kHz
> apart (850 Hz shift??).
> Does this match anyone else's observations?
>
>    73 de Geoff vk2tfg
>
>
Hi Geoff  VK2TFG,

The OSCAR-7 CW telemetry on 70 cm is FSK modulated so that one signal is the
correctly tuned Morse code in wich the key down make a correct sound
corresponding to a line or a dot.

The other signal is the wrong tuned signal  wich produce a tone between  the
space from two letters or in other words the image of  the Morse code
sounding when the key is up.

73" de i8CVS Domenico



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