Posts by HB9SKA

    The description Triplexer in this case is misleading. You can describe it as "Special Bias-T" or "Super Bias-T" ;)

    Any other suggestions ?

    I met the designer of the propulsion system and Mario, DL5MLO, in Friedrichshafen at the AMSAT-DL stand. The system is a test unit and brings the satellite only in a 20 - 30 km higher orbit (LEO).

    Hallo Peter

    In the SATELLITE DESCRIPTION you can read "The main experiment is a new generation propulsion system for Orbital Plane Change (inclination) and/or Orbital Altitude Change and uses green propellant." I think the sat will be shot from LEO in a higher orbit. Further infos will follow, hopefully.

    CU in Friedrichshafen


    PRECURSOR Updated: 28 May 2023   Responsible Operator Mario Lorenz DL5MLO Supporting Organisation Spectrum Aerospace Technologies UG Contact Person Headline Details: PRECURSOR is 15cm x 30cm x 60cm, 18kg weight (including propellant). \it is planned to be launched on an experimental/test flight on a LandSpace ZQ-2 to a geosynchronous orbit in 460km altitude. Current estimates predict a mission lifetime between 1 and 5 years, depending mainly on solar activity and success in the primary mission. The primary mission of PRECURSOR is the in-orbit- verification of an electric propulsion system within ~ 6 months after launch. Due to the power demands of the electric propulsion system, the satellite includes significant electrical power collection capabilities. Once the propellant (reaction mass) for the propulsion system is used up, the power budget allows for several secondary missions: Amateur Radio: - Provide an U/V amateur radio transponder - Enable S/C tracking using telemetry - Provide a software defined wideband L/S amateur radio transponder and/or signal source Educational experiments: - an onboard computer using an intra-satellite wireless bus system (University of Wuerzburg) - radiation sensors - GNSS experiments including a software defined GNSS system (ETH Zurich, Fraunhofer IIS Erlangen) - LPWAN technology verification (Fraunhofer IIS Erlangen) - two cameras - various antenna systems.Other than collecting telemetry and learning about satellite operating environment, an 25kHz linear, bent- pipe Mode U/V will support direct amateur radio operation and involvement. A software-defined wideband L/S transponder will allow for direct amateur radio operation and involvement. Being software-defined, its characteristics can be modified while it is in orbit by uploading new software. On a time-shared basis, this transponder can be used as a bent-pipe transponder, a regenerating transponder, or as a signal source carrying telemetry or live video. For a typical user station, a 250kbit/s link is planned, sufficient for narrowband DATV operations. Stations putting more effort into their ground stations could benefit from higher bandwidths, enabling (2..5 MHz). Other than a purely linear transponder, regenerative transponders of varying modes can be experimented with. This would include 5G and IoT waveforms. We expect to turn on the U/V transponder after initial checkout of spacecraft, about 1 month after launch. L/S transponder will be operated on a time-share basis depending on available power and mission requirements. Proposing VHF and S Band downlinks with 9k6 GMSK telemetry with CCSDS formatting. Planning a launch from Jiuquan Satellite Launch Center in Q4 2023. More info at Application Date: 23 May 2023 Freq coordination completed on 01 Jan 1970

    The IARU Amateur Satellite Frequency Coordination Status pages are hosted by AMSAT-UK as a service to the world wide Amateur Satellite Community


    I think there is something wrong with the orbit specification.

    But WOW, this will be a next super HAM satellite :!::):thumbup:

    Dear HB9SKA,

    DX-Adventure is proud to announce a partnership with the United Nations Amateur Radio Contest DX Club (ARCDXC).

    During 18 | 19 | May 20th we have the scoop to make the very first QO-100 connections from the United Nations - Vienna International Center.

    On the occasion of this activation, there is a special call sign 4U100QO.

    As a token of appreciation, DX-Adventure is donating the equipment so that connections can be made through QO-100 in the future.

    This cooperation embodies the spirit of international cooperation and exchange that the United Nations aspires to.

    DX-Adventure would therefore like to express its sincere thanks and appreciation to the sponsors.

    Your contribution has enabled us to take our QO-100 station and partnership with the United Nations Amateur Radio Contest DX Club (ARCDXC) to new heights.

    During this activation we will also be active on HF with the call sign 4U1A.


    DX Adventure team

    Or are you suggesting that I do not know how to measure the gain of an amplifier :)

    Absolutely not Dear Conrad ;) You are more profi than I. This was only an info for you. I'm not a RF-technician, I use most of my gear in original state.

    Hello Conrad

    I have an EDUP EP-AB003 WiFi booster. I have it cooled down with a heat sink on one side and an ventilator on the other side. Can you measure it again with this little modifications ? I know the booster/PA has a heat problem without it. My signal is clean on the transponder.

    I will try without the amplifier first, but i doubt it will be enough for a SSB contact.

    If you point your dish exactly to QO-100 then it should be enough power. My very first signal over QO-100 was in CW with about 500 mW without amp from the upconverter . The result was a very weak but stable signal on Goonhilly WebSDR.