Posts by DH2VA

    RG-316 has more loss (slightly thinner) but higher temp range compared to RG-174. And don't forget about connector interface losses which are non-neglectable in relation when having short jumpers.

    That said: for a fixed installation, probably UT141 (semi rigid) is best.

    Any amplifier driven too hard (making it non linear) in the RF path will shown this very behaviour (generating 3rd order intermodulation or IM3 for short). You just see them in the example as the low audio are the most prominent contents.

    For those transmitting some kind of waterfall text it is more easily seen as ghost images below and above the letters as the main letter itself is sent with constant levels across frequencies (compared to SSB voice).

    SV1BDS 60 and 80cm should be different in SNR by a bit more than 1 dB only (compared to their 2.5dB difference in gain) as you are already limited by transponder noise. So your pics looks ok to me.

    operators using QO100 do know

    • where to point the antenna
    • which frequencies to use
    • which power is required


    Unless you have very selective reading, it is hard to miss the information about power levels. I don't buy this being anything else but ignorance.

    First of all an apology for the title to the vast majority of users which follow the rules on using the QO-100 transponders. Your activity both as operators but also as hamradio experimenters, builders and ambassadors for our hobby is our fuel to continue working on future amateur radio satellites.


    The following lines are addressed to the few individuals (YOU) which constantly ignore the rules set up by AMSAT-DL. I am writing 'ignoring' on purpose. Not 'bending' or 'challenging' but 'ignoring'. After more than half a year the rules should be obvious to all users. Working QO-100 is by no means an easy feat and we can certainly rule out 'accidental' transmissions to the satellite. Still not a single week passes without me observing your mindless and selfish behavior on the transponder: transmitting outside its authorized frequency limits, exceeding the defined power levels limits and using excessive bandwidth (to mention only a few). Although I will not play the 'shame and blame' game (others are much better at this and I thank those for doing it for me!) you should note that your behavior is gravely endangering the future of amateur radio satellites and our status as 'hitchhiker-payload' in particular! The rules are in place for very good reasons and while you might not agree with them: here they are. I cannot and will not justify them individually (last but not least due to NDA restrictions) and I do not think AMSAT-DL has to. QO-100 is a very generous gift by the satellite operator and a few very supportive persons and we should treat this gift with decency and care. It is NOT a service and you have NO rights on using it. If you do not agree with the rules, I would recommend you to go somewhere else and let others enjoy the gift offered to us. As a reminder, amateur radio via satellites is a low-power mode and there is absolutely no justification to use more power than required to use the transponder. Your constant misbehavior sheds a very bad light on the amateur radio community. It will eventually lead to temporary or permanent stop of QO-100 operations and subsequently kill any future efforts to get similar payloads flying on future commercial satellites. Not only this is asocial behavior against all well behaving hamradio operators but it is a punch in the face of all volunteers of the Phase-4A project which have dedicated considerable time of their lives in the past years to make this happen.


    Thank you for that.

    Don't even bother with trying to see video while the constellation diagram is a circle. You need 4 dots (well, rather blobs) in the 4 quadrants before even thinking about vid. Try marko92's suggestions again, with loop gain and fine tune enable.

    Just to be clear: the picture in the first post from Heiner is the correct picture for the Es'hail-2 satellite (DS2000 satellite bus from MELCO). The other pictures of 'satellites' are just bits and pieces taken from other sats (I see panels from Mars-Express combined with the antenna from the Cassini Mission.. :) ). Looks nice but is not even close to reality.

    Unfortunately, the circulators from Bert do not fit into the space into the amplifier, but he sells SMA type circulators which can go at the SMA output of the PA.

    I expect this is where you want to solder a good 50 ohm load needed at the circulator 3rd pin.

    Mouser order number 581-RP92010T0050GTTR (AVX company)

    50 ohm, 10 Watt, case 2010, good up to 3 GHz

    I would point out amateurs are not permitted to broadcast

    I am not sure about that.. I know from G8GTZ and G8GKQ that this is indeed true for the UK. At least in Germany, this is much more relaxed as we have regular and fully official hamradio broadcast programmes ('Rundspruch').