What TX amplifier do you plan to use?

  • I use this kind of surplus pallets. Around 3 mW in and (measured) around 30W @2.2, 20W @2.3 and with some tweaking 11W @2.4 GHz output.

    Overall efficiency @2.4 GHz is not very good, but what the heck . . . for 10 Euros (!)

    Were can I get these modules, are they still available?

  • PA5CW Bought them in 2016 on 'the Jutberg flea market' to build my first Es'hail-2 transverter. (Because of that) Others bought them too and I haven't seen them ever since. I got a mail from somebody from Italy a long time ago about how to get the pallet running and mods for 2.4 GHz. So apparently they were available in Italy too . .

  • PA3GUO

    Looks very good. :)

    By the way, the directional coupler at the output can be omitted and thus may bring a few tenths of dB more output power to the antenna. The amplifier already has a coupler built in and you can simply connect the power meter to the second MMBX socket. The corresponding calibration value has to be determined of course, but this would be necessary for the external coupler as well.

    But one could also realize a deluxe version and use the external coupler to measure additionally the reflected power.

    With the 25 euro power meter via Ali connected to the directional coupler.

  • Over the last 2 months I worked on the amp, original designed by PA3AXA, Rens.

    After eliminating all problems and a lot of optimizing after pimping the amp, I am proud to say: It´s done.

    The "next" version of this amp is running smooth and cold, with less current, lower Voltage but much more gain.

    Gain: 60dB , up to 66dB (minimum ~50dB)

    Rated constant output: 20W

    Max Out: 35W but thats overkill even with low currents!

    Max input: -17dBm! (Pluto has +3dBm @100% drive)

    It´s super linear. Hope Matthias DD1US can catch a sample to go deeper into measurements than i can do with my siglent SSA3032X analyzer. But psst, he doesn´t know that :)

    The plan is to build up to 10 pieces. Ready to use with 12V + 26V (24V).
    The 12V can be used as PTT or running 24/7. The heat with low currents isn´t high.

    If you are interested write me an email: dm4ds@gmx.de (please give me 1 2 days for answer)

    I hope to update my homepage soon with more informations and pictures + Videos of the measurements.

    Here are some pictures: while the minimum of my TG is -20dBm I inserted an extra 10dB attenuator.

    the PCB

    Case all will be build


    MAXIMUM Output with -13dBm input!

    After 10 minutes passic cooling @20W constant output sweep