[amsat-bb] Chinese Lunar sats

[Scott]

Greetings!

The software on github  (https://github.com/bg2bhc/gr-dslwp) is for use in 
GNU Radio on linux, so a Windows computer would not be helpful for that.

In the hours after launch, several Amateurs 
(http://lilacsat.hit.edu.cn/dashboard/pages_en/contribute.html) 
successfully decoded the 70cm telemetry using those GNU Radio flowgraphs (I 
got some partial decodes but low SNR here prevented me from getting complete 
packets - but I was still very pleased!).

Last night (U.S. time), I'm not aware of anyone receiving any of the 70cm 
telemetry.  We were asked to watch for JT4 as well, but I'm not aware that 
any was received.

As mentioned earlier in this thread, the team has lost S-Band contact with 
one of the cubesats.  I'm not setup to receive those frequencies but others 
are watching for the signals.

For an average station like myself, the plan will be to continue to watch 
for 70cm telemetry with the GNU Radio software & JT4 with a second SDR.

Hope that helps!

-Scott,  K4KDR


===========================================

-----Original Message----- 
From: Jean Marc Momple
Sent: Tuesday, May 22, 2018 12:21 PM
To: Nico Janssen
Cc: AMSAT BB
Subject: Re: [amsat-bb] Chinese Lunar sats

Nico,

I have been trying to capture the signals from the both Longjiang sats for 
the past 2 days.

On Monday it seems that I receive a carrier on the right frequency but was 
not able to confirm that it was from Longjiang 1.

I used the initial Keppler’s and now using Celestrac in SatPC32 which seems 
to be OK when comparing with N2YO ele/az. I have been monitoring on the 
announced FX and having also JT4G “on” for about this evening without any 
results.

For sure I am doing something wrong but cannot figure it out due to the lack 
of information.

Also, trying to get a decoder software for the GMSK telemetry is quite 
difficult for a non-IT geek, I don’t have clue how to have the published 
GITHUB decoder to work on my Windows computers…

Here we are this side.

Quite frustrating that the communication is not that good, as if the project 
team want the maximum of feedback and TLM they should provide a minimum of 
info. Just a personal opinion.

Anyway will try hard to receive these birds as a real opportunity for HAM to 
learn more on outer space com, if anyone can help and share, particularly 
the guys who already decoded the birds, it would be more welcomed.

73



Jean Marc (3B8DU)





> On May 22, 2018, at 5:03 PM, Nico Janssen <hamsat at xs4all.nl> wrote:
>
> After their launch on 2018-05-20 at 21:28 UTC, LJ 1 and LJ 2 were
> maneuvered onto a track to the Moon. Several amateurs received
> telemetry from the satellites. But now LJ 1 appears to encounter
> problems.
>
> Quoting Wei BG2BHC:
> "Can you help to find amateurs in the US to help to monitor DSLWP-A
> on 435.425 and 436.425 now?
> We lost the contact of satellite A on S band after an orbit adjustment.
> We just tried to switch on UHF, but we don't know if it works or not.
> The sat is just above South America.
> If it works, 435.425 should be 500bps GMSK and JT4 alternately.
> 436.425 should be 250 bps GMSK.  Bothtransmit once in 5 minutes.
>
> Thank you very much!
>
> Wei"
>
> 73,
> Nico PA0DLO
>
> On 22-05-18 12:15, Mike Seguin wrote:
>> Any word on the two Chinese microsats LongJiang 1 & 2?