Posts by DH0SK

    I would say there is something wrong with your output-power or antenna-gain or cable-connection. In addition as already mentioned before the antenna is not the cheapest. My construction is 15€ and works well for TX and RX with one reflector. I would use this solution if a dish can be mounted in your environment.

    Hello Kai,

    can you tell me, where I can get this nice housing ?

    73, Martin

    Hello, its from ebay:

    Halbschalen-Kunststoffgehäuse EURO-BOX, 205x180x70mm, schwarz

    Halbschalen-Kunststoffgehäuse (205x180x70 mm) mit schraubenlosem Schnappverschluss und austauschbaren Frontplatten.

    Art. Nr at ebay : 322497818759

    73 de Kai / DH0SK

    Hello, is their a link for the Image? Maybe i overlooked it ? Is the Raspi SW able to correct the drift?

    My Raspi QO100 Receiver with same design as the Transmitter is now ready besides the SW Image. Maybe someone can point me to a link.

    Pic. 1: new QO100 Raspi SDR Receiver

    Pic 2: the Transmit Box LZ5HP with 25W PA same design as SDR Raspi Receiver

    Now with the Raspi Image my small Groundstation is ready 😁

    73 de Kai

    Hi Michael,

    thanks for the very good explaination. I have still twenty of the GM201 and will start to modify with your idea.

    The only open question ist the bias/triplex er for single cable solution. Do you have a schematic of that part?

    Thanks in advance



    Hast du den LNB umgelötet das er eine ZF im 70cm Band erzeugt ? Ist die stabil ?


    Ja ich hab den Quarz getauscht und kann somit mit dem LNB im 70cm Band empfangen. Fuer mich war die Stabilität im ersten Ansatz ausreichend (SSB Betrieb) . Verbesserungen (TCXO, GPS usw.) werde ich spaeter machen.

    73 de DH0SK

    Hello all, thanks for the answers to my question regarding the 70cm IF. Meanwhile i got a Signal on 70cm with that Pollin LNB but not on the expected frequency. The Quarz from eBay from austria was indicated with 25,788MHz. I expected the beacon on 432MHz but i found the beacon on 430,081MHz. Its difficult to have two parameters wrong (frequency and direction). Maybe the Quarz was wrong or the PLL factor i assumed was wrong?

    Btw. I was wondering about the good stability of the Pollin LNB. For SSB it was fine for me. With additional aluminium foil arround its ok.

    73 de Kai

    Hello, I search for someone with experience on Pollin LNB Golden Media GM201:

    I soldered a christal for 432MHz IF (25,788 x 390) but nothing received.

    I am not sure if the PLL is locking and/or the IF Filter is blocking the 432MHz IF.

    Did someone has experience to use the GM201with a christal for 432MHz IF ??

    Here my just ready built Transverter (SG Labs) for robust portable use together with FT897. The portable Dualband Antenne needs to be developed now. This will be used out of the Motor Caravan in summer. The output Power can be regulated to adapt to the portable Situation. The small old style instrument shows the output power (forward or return) switchable. 73 de Kai

    Congratulation to the whole team to the great success of that project. Nice to hear the beacon sound back which i known from the late 80s when i was a young boy. Nice to learn that this kind of projects in Ham Radio is still feasible. I am sure this project could be a good justification for further projects. Now its time to build my uplink station.

    Thanks to all involved in that project - i know how difficult the space business is today.

    73 de Kai

    Nice, i search for Payload Engineers ;-)

    73 de Kai

    Maybe i can explain in the frame of the discussion regarding 'unwanted signals' the IOT phase:

    Before the IOT starts there will be a TRR (test readyness review) in front of the customer. All the testplans and test-specifications will be reviewed. When the test is done there will be a TRB (test readyness board). In the TRB they have to show/present all the measurement results (e.g. inband performance like Gainflatness, Groupdelay... aso.) and compare these results with the specification in the contract. Each unwanted signal makes the measurement difficult and needs to be explained or leads to a so named NCR (non conformance report).

    The IOT will be done in shifts/nightshifts and with unwanted signals (if not explain able) some measurements needs to start again and again and leads in addition to a delay for the handover and operation of the satellite.

    Maybe that helps to understand why it is really important to have only the IOT uplink signal.

    To measure the pattern of each antenna the satellite will be moved east/west by the propulsion system of the DS2000 Bus and the signal level is measured by the IOT station on ground (some cuts) .

    The commercial beacon can maybe be switched from LEOP Omni antenna to on station antenna when the satellite is placed in the final slot. This should be the reason for the change of the commercial Ku Band beacon signal level the last days.

    Best Regards