[amsat-bb] Info of Chinese Launch 2016-066

Alan Kung camsat at vip.163.com
Sun Nov 20 18:14:42 UTC 2016

Hi Drew,

Thanks for your report! 
I think the problem is not lack of electric energy, CAS-2T is an 2U structure, we installed solar panels on five sides with 30% efficiency, average total power about 2.2 Watts, the power budget: CW Beacon=0.5W, FM Transponder=0.7W, OBC=0.05W, TT&C Receiver=0.12W, Total=1.37W, normally there is some superfluous power to supply to heating resistances.

What problems are I think: First CAS-2T was not separated from the launch vehicle, final stage of the lauch vehicle is much bigger than CAS-2T satellite, and it keeps self spin in approx. 7 seconds per circle. It lead to the antenna radiation pattern becomes chaotic, the gain at some positions become much lower and is accompanied by a parasitic amplitude modulation. On the other hand, in order to avoid chaotic signal on VHF from land in East Asia to disturb the Satellite uplink , we adjusted the uplink receiver squelch at very deep position, it makes the transponder opening sensitivity less than -110dBm at RF input port of the receiver.

So I think the solution is only to improve the uplink EIRP, some of the high schools' club stations here using 3 meters boom antennas with approx. 50W RF power to get through the transponder well.

Alan, BA1DU

At 2016-11-19 08:29:06, "Andrew Glasbrenner" <glasbrenner at mindspring.com> wrote:
>Hi Alan,
>I have listened to CAS-2T on several passes now. I can make the repeater
>transmitter come on by transmitting on the uplink, but as others have
>pointed out, nothing is repeated. The downlink is intermittent and choppy,
>with no audio apparently passed through. It almost sounds like older
>handhelds would sound on transmit with a low battery. I wonder if it's
>possible to try turning the CW beacon off? It would be great to recover the
>satellite, as it is in a very nice orbit!
>73, Drew KO4MA
>-----Original Message-----
>From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Alan Kung
>Sent: Wednesday, November 16, 2016 10:58 PM
>To: amsat-bb at amsat.org
>Subject: [amsat-bb] Info of Chinese Launch 2016-066
>Satellite Name: TY-1
>Mission: Technical experiment
>TT&C: 437.5MHz  Bandwith 300kHz
>Satellite Name: CAS-2T(Dream-1)
>Mission: Education, Amateur radio, Technical experiment CW Beacon:
>435.710MHz FM Transponder Uplink: 145.925MHz FM Transponder Downlink:
>Satellite Name: KS-1Q
>Mission: Technical experiment
>TT&C: 436.5MHz  20kbps GMSK
>Satellite Name: Pegasus-1
>Mission: Technical experiment
>TT&C: 468.0MHz  FSK
>Alan, BA1DU
>Chinese Amateur Satellite Group(CAMSAT)
>Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available to all
>interested persons worldwide without requiring membership. Opinions
>expressed are solely those of the author, and do not reflect the official
>views of AMSAT-NA.
>Not an AMSAT-NA member? Join now to support the amateur satellite program!
>Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

More information about the AMSAT-BB mailing list