Posts by OE3MZC

    AMSAT-OE announces an activity of four Radio Amateurs from Austria

    operating on geostationary satellite QO-100 from 13. April till 29. April 2023 from Republic of Maldives (8Q).

    The team consists of (They have been granted licenses):

    • Larissa OE3YLR as 8Q7LZ
    • Barbara OE3YCB as 8Q7BZ
    • Florian OE3FTA as 8Q7FZ
    • Mike OE3MZC as 8Q7MZ

    and will operate from RAKEEDHOO Island in grid locator MJ63rh in the Indian Ocean.

    The dish size will be only 37cm to fit into the flight case.

    Please observe downlink QRG 10.489.732 (the OE-activity center) for split operation in SSB.

    more info see:

    Danke Martin,

    für die Tipps , der MOS-FET ist ok.

    der BIAS-Strom wird durch die erste Verstärkerstufe (Driver) kurzgeschlossen. Die 5V knicken ein.

    Ich habe jetzt die L1 Spule weggenommen, durch die der BIAS Strom eingespeist wurde, und jetzt ist BIAS -Schaltung mit +5V OK.

    Scheint also der Driver Chip RF2126 (IC2) defekt sein.

    Interessant ist, dass dieser Fehler bei verschiedenen Versionen von PA-Platinen auftaucht. (sowohl bei der neuen weißen als auch der alten dunklen Platine). Die neue Version hat als Driver scheinbar einen Transistor als Driverstufer U8. Weiss jemand welche Transistor Type das ist?


    73 de Mike, OE3MZC


    ich habe genau das gleiche Problem. 12W PA von DXPatrol gibt keine Leistung mehr. Schaltplan wäre hilfreich.

    Wobei es gibt mehrere Versionen. Die letzte mit weisser Platine.

    Gibt es eine Möglichkeit mit DC-Spannungsmessung die Funktion des Endstufen Transistors zu prüfen?

    danke für jeden Tipp.

    73 de Mike

    DXPatrol GROUNDSTATION is a great product,

    simple to use for everybody,

    has good reception -even with small dish (35cm)-

    output power will never trigger LEILA, if you use some meters of coax cable from groundstation to antenna and dish is smaller than 75cm.

    if you hear some station calling CQ, you can just answer on same QRG and will be perfectly on frequency- no OOHLAA or whistleing needed.

    Working great with WINLINK on VARA-SAT with IS0GRB.

    GS is perfect fit for EMCOM emergency communication!

    ok, it will take 3 mins to lock oven and GPS

    but there is nothing more compact and simple for holiday-DXpeditions or similar.

    I am QRV on QO-100 since the beginning and have done all the experiments with two TRX, BU500 upconverter, modified LNB myself, Bodnar GPSDO, IC-9700, and RTLdongle and PLUTO and LimeSDRmini, SDRConsole etc...

    So most stations that call me OFF-frequency or trigger LEILA or have bad signals or bad behavoir in Pile-up

    have been using some homebrew complicated equipment capable of be honest.

    So I think we should be more open and not argue for the "RULES" sake.

    BTW: Germany likes RULES - except on their highways-hi


    I appreciate ur work on MMDVM, but I am not sure abt ur statement:

    For example, DMR is originally not open and fully documented. Some things have been reverse engeneered. We all mostly use MotoTrbo Tier2, which is fully proprietary of Motorola (even with Hytera radios) and also your MMDVM is using a VOCODER-chip (AMBE), that you need to buy and use in hardware in order to have a license for it. So I cannot see any difference to Lora at all. So also Lora is fully documented and you can buy chipset for 433MHz very very cheap! So why not using it?

    73 de Mike

    Dear Peter,

    dear all,

    certainly LORA is fully legal to use in Amateur Radio in most countries. It is not encrypted. It might be proprietary, but C4FM, DStar, DMR P25 is the same in many aspects and still widely used in Amateur Radio Service. Lora-APRS is fully compliant with the APRS standard from Bob Bruninga, WB4APR. So in terms of "experimental" we should welcome these experiments. Ofcourse it is true that the bandwith will only fit the QO-100 wide band transponder. But I understand, that the wide band transponder is intended not exclusevely for DATV, but also for such data transmission experiments and services. Lora is a good example that not only very narrow banded modulation techniques (FT8, WSPR) can give excellent results with very low power but also "spread spectrum" type (see GPS).

    Currently LORA-APRS is spreading accross Europe on 433.775 on 70cm band ( . WIth just 50mW you can make position data transmission over 100km from your car or backpack. So to have a Region1 APRS channel for Lora-APRS on QO-100 could be a super service also when travelling very remote areas in Africa or elsewhere...

    So lets welcome innovation in Amateur Radio!

    73 de Mike, OE3MZC