Delfi-n3Xt: Request for help on S-band reception

Dear all,

It has been a while since you heard from us. We are still having problems to receive our satellite since our transponder test. We now want to try something different: trying to activate our S-band transmitter and let it transmit at full power for a pass. If we are able to receive a signal from the S-band, we know that Delfi-n3Xt still has an operational receiver and we could potentially demodulate the S-band signal. But since we already know that the latter is difficult, the first focus is just to “see” the signal. Since the satellite is still tumbling, it is a matter of link budget and statistics if we are able to catch the signal. To increase our chanceswe would like to ask the help of radio amateurs in the neighbourhood with suitable equipment. Since we have to actively command the satellite we have planned the passes which are suitable for the Netherlands, Germany, Belgium and Northern France and the availability of operators from our side. According to a quick survey, you are living in the area in reach at the selected passes.

The question to you:

Do you have S-band (2405 MHz) reception functionality with a dish of at least 2.5 meter and tracking capability and willing to follow and record one or more passes for us?

If so, please let us know your location, the gain of your antenna and the passes you are able to follow. Off course you do not have to be actively present during the pass. You can just record it and send the recording later through www.wetransfer.com.

Delfi-n3Xt will send at 2405 MHz +/- 100 kHz. The latter is the worst case uncertainty band, but I expect it to be pretty close to the right frequency. If you have an SDR, you can best set it at +/- 1 MHz around the centre frequency. Off course you do not have to be actively present during the pass. You can just record it

The planned attempts are stated by the LOCAL time of commanding below. If successful transmission would be within the 10-20 minutes after the indicated time.

• Tue 13-05 ~11.25h local time
• Wed 14-05 ~12:00h local time
• Thu 15-05 ~22:10h local time
• Fri 16-05 ~11:35h local time
• Sat 17-05 ~12:10h local time

If you are able, your help is highly appreciated!

Vy 73,
Jasper (PC4JB)

Coming, Delfi-n3XT Linear Transponder tests

We are going to test the transponder functionality of Delfi-n3Xt this week. I have to be honest that this functionality was implemented last minute on the satellite and was only tested briefly in a non-representative setup. I therefore estimate the chance that it will work at 50/50.

Our first series will be at:

• Thursday 20-02-2014 at about 10:50 UTC
• Friday 21-02-2014 at about 9:50 UTC
• Friday 21-02-2014 at about 11:25 UTC

After a few initial tests, and provided that it works, you are free to use the transponder for communication. We will leave it in this mode for the remainder of the sunlit part of the orbit, so only in Europe and Africa it is possible to use this mode for now. If successful we will turn on the transponder more often and for longer periods of time such that everyone can enjoy it.

Frequency:

Uplink 435.530 – 435.570 MHz LSB Linear transponder
Downlink 145.880 – 145.920 MHz USB Linear transponder (inverting)

DELFI-N3XT              
1 39428U 13066N   14038.63217054  .00002453  00000-0  43939-3 0   699
2 39428  97.7772 111.8003 0129782 303.2748  55.6102 14.62338302 11392

Source: PC4JB, Jasper Bouwmeester, Delfi Nanosatellite Program Manager

Delfi-n3XT Telemetry 11-01-2014 10:09 UTC

Decoded with Maspro UHF yagi, SSB preamp, FUNcube Dongle Pro+, SDR# and DUDE Delfispace ground station telemetry decoder. After that the raw packet data was used as input for one of the nice decoder software packages from Mike DK3WN.

The latest versions of the software packages from Mike come with a save function that makes a transparent screenshot from the software output. A very nice new feature. Thanks Mike.