Delfi-n3XT Transponder test

Coming, Delfi-n3XT Linear Transponder tests

Delfi-n3Xt Earth

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.


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

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

7 thoughts on “Delfi-n3XT Transponder test

  1. First Transponder Test.
    Dear all,

    Today we did a first transponder test. We could hear the beacon, but unfortunately did not hear anything back from our calls. Also we were missing the noise floor of the transponder band. Our hypothesis is that our adjustable LO (Si570) which is mixed with the IF band could not be programmed correctly and hence the pass-band goes outside our filtered band (which is a good thing, because we do not want to transmit on illegal frequencies). This LO is adjustable by I2C communication and should be programmed each time at power up (so each time the transponder mode is activated. We will do two attempts more tomorrow at the morning ground passes and even if that doesn’t help we will keep on trying with different settings. If the situation changes I will update you again.

    Best regards,
    Jasper, PC4JB

  2. Hi Etienne (ZS6Y)

    I started early this day so I could monitor the transponder, but nothing heard between 11:20 – 11:34 UTC. No beacon and also no downlink signals from the transponder.

    During the pass between 13:00 – 13:08 UTC I will listen again.

    73 Jan PE0SAT

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