• Official Post

    To all QO-100 users and friends,

    We urgently need your help and support!

    This morning (around 05:25-05:33 UTC, 2019-09-22) Alarms were triggered in the Es'hailSat satellite control center in Qatar due to High Power uplink on the NB transponder!

    Considering the safety of transponder they may SWITCH OFF the QO-100 transponder in case if it exceeds the limits again.

    Please accept and respect the transponder guidelines rules and band plans.

    1. Please stop running high power, even not for experiments or try-out! If you want to test your power, please use a dummy load and power meter.
    2. Keep your Downlink strength at the same level as the CW Beacon, maximum one S-Unit above will be tolerated!
    3. Stay within the borders of the transponder. Do not transmit below the CW Beacon and do not transmit above the PSK Beacon!

    Please help everyone on QO-100 to adjust operation practices accordingly.

    Please be friendly and polite with other OMs on QO-100, but don't hesitate to give them reports.

    Please spread the words!

    Original notification below:

  • DB2OS I like your post, but I don't like its contents : -(

    It was not a matter 'if' , but 'when' this should/could occur. Unfortunately you can't force 'the customer' (like for 'normal' transponder rentals) to reduce uplink power, but hopefully you and your team have sufficient measures to prevent TPX mute.

    Edit: This weekend is the ARRL EME contest 2.3 GHz and up ....

  • Honestly, I believe most of the so-called pirates are just legal radio amateurs playing around or are ignorant.

    I also believe this statement to be true.

    Some time ago I posted a question Is there a Too Much power warning on the NB transponder, would it be an overlay in Spectrum or waterfall? as I was seeing signals well in access of the CW beacon. I heard Pirate Hunter talking on the very large signals outside the digital beacon when we had the Russian sounding voices playing. I was very surprised there was not an alarm raised at the time.

    @all and also please avoid tuning with a carrier better using your microphon.. :thumbup:;)

    I hope the comment gets through.

    A quick question on power, I am sure I read that the power should not exceed the level of the CW beacon when sending a single carrier, so in effect speech would always be below the CW beacon level, although I can not remember where I found this, is this correct?

    I do hope the transponder does not get muted, or if it does it is only for a limited time frame.


  • Greetings to everyone ,

    It is OK to check the POWER !! , but we DO NOT FORGET QUALITY.

    Very often, we listen to KNOWN stations, and of great experience, transmit in voice without any control, in the output volumes, out of frequency (tolerable) and above all with excessive distortion.

    Of course the SATELLITE is very useful for experimenting, I did it myself, I do tests continuously, (BUT I AM ONLY TESTING), in the normal way I try to transmit in the best way and form possible, I think it is the first sign of EDUCATION, towards the station who listens, so they taught me ...

    I always read you with so much INTEREST and ESTIMATE !!

    BEST 73 ..



  • Position of the moon at 5:30 UTC today:

    Thanks - this was behind my comment knowing it was an EME weekend and the interference was fairly short could it have been an EME signal that happened to align with the satellite. Someone with the data and more patience than me could work this out and even geolocate to some extent. We must remember we do not have exclusive access to 2.4 GHz and we should not deploy systems that are not tolerant of these other users.

    2400-2402 is the narrow band segment in countries that do not have access to 2320/2304. Therefore it is quite possible and legitimate for someone to be operating in 2400.05-2400.300. That's presumably why this band was chosen as QO-100 uplink as many have access and there is an amateur satellite allocation. Many of the countries that do use 2400-2402 are not in the footprint but on an EME weekend there is a strong possibility stations that are will be using these frequencies trying to contact others. I note the moon was up in asia at the time, EU-Japan EME?


  • "according to the location of the moon shown in the image from DD4YR - the moon was exact in east direction of QO-100"

    Johannes, this is the sun. The moon is over the Sahara.....

    73´s de Robert

  • Unfortunately I do not believe Leila will work in this situation even if the signal had been within the 2 beacons.

    Leila appears to transmit a signal on top of someone operating with excessive power. This just makes the situation worse as now you have 2 high power signals. However, I was under the impression that the NB transponder had AGC and the WB transponder does not.

    Is it not possible to set the AGC threshold to limit the total output power below the maximum limit....and way below any level that will trigger alarms in Qatar?

    73 David

    • Official Post

    It's much more interesting to make QSO's with low power than with high power. This is my personal conclusion after 3 QSO's with PY and 1 with ZS today. It's very important that you have a clear modulation and your signal is not overdriven. It's also important that you talk clearly and not too fast.


  • Ahh, but the norm is wanting a 59+ signal with lots of processed audio and wide band signals as mentioned by M0EYT some time ago.:)

    I have not heard/seen a Leila signal on the narrow band section, but why would it need to be at the same time as a large carrier, and not as the carrier drops as say a short 800Hz tone at end of transmissions. The ones wishing to cause issues with the satellite would not be bothered, but respectful operators would then know they are hitting the limit and should reduce power.

    How it can be accomplished in software I admit to ignorance, but there are software people out there that I am sure can do it. The wideband visual system appears to work well and operators do take notice of the system, but I appreciate on NB a visual only system may not be noticed if we run spectral views on our own PC's.

    Anyway, I hope a solution is found soon.