Posts by DH2VA

    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').

    I am absolutely ok with everybody asking before actually doing anything.. it's a bit like RX before TX. :)


    Experimenters Wednesday has a long history on the former AMSAT satellites and we would like to keep it that way. Just announce what you are doing in the forum and WB chat and keep trials to a reasonable time span.

    Sorry to be precise.. but in the WB guidelines, neither DATV nor ATV nor TV are mentioned. However, DVB-S2 is:

    Transmissions should use DVB-S2 where possible.


    So I think (although I agree it could be clearer) IP via DVB-S2 is fully in compliance with the WB operating rules.

    hmm.. just checked the WB op rules and I cannot find anything that says that the DVB-S2 stream needs to be video. So even by the rules, IP encapsulation is totally fine and if not, we can/should clarify on this because in my personal opinion IP-encapsulation in DVB-S2 is much more suitable for sat ops than any of the HF modes (Winlink, etc.) on the NB.


    Just beware that with IP encapsulation the traffic still needs to be transparent according to hamradio rules. No encrypted traffic (no https and no ssh for example).


    And don't forget Wednesday:

    On Wednesdays (UTC time), experimenters are encouraged to try other modes – perhaps 6 MS using the whole transponder for brief (less than 10 minute) periods. It is essential that users to announce their plans on the chat room page, and to always monitor it.


    Just a remark on the harmonic content of the LO: it is irrelevant.

    Any mixer is non-linear (otherwise it would not mix) on its LO port. Some mixers work even best when being driven with a square wave on its LO port. Filtering is only required on the IF and RF ports but be careful: to make the mixer work to its specs, all ports need to be terminated with 50 Ohms broadband. This is not true for most filters outside their passband as they reflect the blocked signals back which then can generate additional spurs in the mixer. Special reflectionless filters exist but its usually better to have some broadband isolation between the mixer port and any frequency-dependent component.

    Ich denke 'Drive 80' ist viel zu hoch.. ich glaube mal irgendwo eine Messung des PLUTO gesehen zu haben und faktisch muss der ziemlich runtergedreht werden. Ich hab bei mir Drive 30 und damit sowas wie -20 dBm nach einer Messung von DD1US. Um die Leistung dann wieder hoch zu bekommen habe ich einen 'analogen' Gain block von Ebay, der mir ca. 30 dB macht, also dann knapp +10dBm fuer die naechste Stufe.