Posts by PA3AOD

    Hi all,


    Update of my problem:


    It's a pitty but they will not publish the circuit diagram for the "Universeller Empfang Mischer für QO-100" from Amsat-DL........


    There is a way to get the schematic and that is reverse engineering, but it takes some time.

    Luckily the main components are known and with the data sheet (LNBH26) from the manufacturer you can do a lot


    The search for the fault as succeeded, one of the diodes at the output of the LNBH26 is shorted "0 Ohm" in both directions thats not good.....

    But luckily the LNB26 has a built in protection for short circuit.

    As you can see in the data sheet of the LNBH26 the diodes round the IC are not so critical.

    By lack of a SMD diode i replaced it with a 1N5818 also a schottky diode.

    The 14V is back and the converter is running now for a week without any problem.


    Maybe one question remains, why did the diode fail?

    Hi all,


    My Amsat-DL "Empfangmischer" is broken ;( (and that allready after a week use).

    Is there maybe a schematic diagram available.

    Version on the PCB is V3

    Problem, the left LED is out the middle is on and the right one is blinking.

    The 18V is on the Wide-band connector is good, but the 14V on the Narrow-band is missing.


    Bert PA3AOD