Posts by DH2VA

    Jean-Pierre, I thank you very much for beta 0.9 which works really nice for me (88cm dish).

    As a general remark, thank you for all things you did for the amateur radio community. Without people like you, we would not be where we are today!

    Da kommen wir wohl von unterschiedlichen Seiten des Spektrums.. auf der Mikrowelle ist nachstimmen nicht so ungewoehnlich, selbst bei terrestrischen Systemen. Aber das ist ja das Schoene: jeder kann aufruesten, wie ihm beliebt, die technischen Loesungen sind so viele! Viel Erfolg heute nachmittag!

    We modified the TS-2000Xs for the AMSAT groundstations and disabled the PA in a very similar way (unplugging the internal coax cable) and saw the same connector inside. Maybe this is a (Kenwood?) proprietary coax connector for internal use? I have not seen it in the 'wild' myself..

    To tell somebody that he is running too much power, we would need to know who to talk to (contact me directly.. my email is in the web..). LEILA is not fully commissioned yet, please stay tuned. But it will be only a marker/siren which people may choose to ignore (especially when not working full duplex).

    Thomas, I understood you very well. A multifeed satellite antenna serves several satellites on different orbital positions. While the 2.4 GHz signal will not influence the 10GHz reception, only of of the two will actually target QO-100. The other feed will just miss the satellite.

    Ich hab gerade mal nachgesehen: < 300 Hz in 5 min. Fuer mich persoenlich vollkommen unproblematisch, da war ich von AO-40 viel mehr gewohnt. Aber meine Antenne steht ab ca. 12h LT im Schatten, keine direkte Sonne.

    They are decoupled in a way that the 2.4 GHz is too big to fit into the 10 GHz waveguide (see 'cutoff frequency'). The problem may be (with larger dishes) that the mechanically required separation at the focal plane will result in a angular offset between TX and RX beam. You can of course compensate by raising the output power.. :(

    Gentleman.. please keep it nice.


    Personally I have seen variations of 15 kHz and more on my unmodified LNB but these swings are very slow and do not pose and problem for me for neither SSB or CW as a 1 degC change is taking low in my unshielded setup. Other modes might be affected more.

    Some want their system connected to a central GPSDO, that is ok. I do have a couple of those (and I claim I know the internals quite well as I did some own designs as well). Still, one *can* work SSB and CW with an unmodified, unshielded LNB. Demonstrated many times. But it is true, you can do much better if you are willing to spend the time and effort (and money).

    It is always a tradeoff: we could have designed the transponder to work with a piece of wire only, but then all power would have to go into one single QSO. We had to define a minimum ground station for SSB and this was 60-80 cm (depending on location and weather). For CW, less is possible even today and for JT65/FT8 probably even less.

    You misunderstood me. Due to the transponder coming out of the saturation and being more linear even for wideband signals we see these things now which we did not before. There is little we can do about except making the transponder less sensitive.

    It *could* be any S-band radar system..

    Lucio, no worries! We are pleased that so many OMs monitor the transponder so closely! Sadly, I have just witnessed an FM signal from an OM-station.. easily copyable on my 88cm dish but apparently he cannot hear himself back.

    I can see the signal here in HB9 as well. Actually due to the transponder gain decreased, the system is working better than before (transponder coming out of saturation) so although unpleasant, this kind of interference is not completely unexpected.

    DN1HRZ sadly no.. the sun is not exactly in the south in Germany at 12h local time. I would advise to get either a real compass (not the smartphone ones) or better to use the Az/El from Satlex, which for you is 163.8°/29.7° and check on Google Maps for a geographic point which is in the correct heading. 29.7 deg should be indicated on any proper sat-dish as elevation so this should give you a start point to optimize from. Good luck and let us know if you run into problems!

    I8LYL former I0LYL we had the NB transponder adjusted twice in this period to optimize the dynamic range (and not waste satellite power into noise). The transponder gain was decreased by 4 dB on Feb 28th and another 6dB on March 13th. So in total this should amount for 10dB less transponder noise, which is close to what you see.


    But as you still see the transponder noise, your system is still fine. Note that the beacon levels have been increased as well.