What TX amplifier do you plan to use?

  • Hello I did some modifications and some measurements on this Siemens Nokia PA block.


    As I got the tip from Manfred DK5FA I got 2 units.



    PA with 2x BLF8G22LS,


    if you follow the link you can load my modifications so far.


    The document is only in German. I include also the schematics for the bias current regulation for the final LDMOS and the driver MOS. I hope this is helpful for you.


    Has anyone a info about the directional coupler and the output at X102




    73, Jürgen DL8SDQ

  • Has anyone a info about the directional coupler and the output at X102

    Hallo Jürgen, erstmal vielen Dank. Sehr schön gemacht. :thumbup:


    Und bei so viel guten Meßgeräten könntest Du doch an X102 einfach mal messen, was rauskommt ?

    Oder hast Du kein Dummy-Load für die ca. 100W am Hauptausgang ? :)

  • I can confirm...

    I have now 2x these UMTS working..

    First one i damaged the coupler..

    But with the second i prepared the the output with additional SMA..


    And i use to measure my output for reference..

    Be aware, the output can really change if output is not 50Ohms..

    I have seen more than 50% difference in output due to bad connectors witch off cause don't show on the referenced output.

  • Habe jetzt von DL8SDQ folgenden Link mit Erfahrungsbericht zu meiner Anfrage erhalten, falls noch jemand die PA hat:

    I have got this from DL8SDQ, could be interesting for others with this PA:


    https://groups.io/g/DATVPA/topic/200_watt_bison_amplifier/74345607?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,74345607#


    Und das ist auch eine SIEMENS/NOKIA-PA, nicht BISON-PA, aber made in Poland.

    And it is also a SIEMENS/NOKIA, not BISON. But made in Poland.

  • What would be the max DC input for the UMTS siemens/nokia amplifier.

    Currently running on 28V and i know 32 Volt is mentioned but the max ratings of the LDmos are much higher.

    I have a 400 watt 35Volt DC supply and i just wonder if the gain and more important the efficiency would benefit from a higher DC input.

    Or will i just smoke some parts...

  • Yes, Max voltage for ldmos might be higher but beware voltage on drain is twice the dc voltage in normal Operation when fet is Not conducting- Always keep Supply Volt below half of max drain voltage

  • Hi Oscar,


    can you let me know where i can find these items, i ned two for my PA Nokia UMTS...


    TNX. Gio - PA1KEK

  • my colleagues once described an amplifier that was to be processed and I have a problem with it because it raises and I do not know how to eliminate it even after the transistors are rescheduled it is still the same maybe you have some advice.