Contests on QO-100 allowed

Contests on QO-100 allowed

April 4, 2021 Off By Peter Gülzow

Effective immediately, we are opening the QO-100 NB transponder to general contest operation in the upper mixed-mode range.

Updated band plan

valid: from 4 April 2021

Contest Zone (CW and SSB)

Uplink area 2400.370 – 2400.490 MHz
Downlink area 10489.870 – 10489.990 MHz


Of course, the usual QO-100 NB transponder guidelines also apply here. Therefore, the bandwidth should still be limited to 2.7 kHz and the transmitting power should be reduced to the necessary level, i.e. only as much power as necessary should be used.

Experimental Multimedia Beacon

The attentive observer will not have failed to notice that the upper limit of the mixed mode range is now 10489.990 MHz. This is because the upper CW beacon at the end of the band will soon be changed to an experimental multimedia beacon, based on DJ0ABR’s AMSAT-DL HS Multimedia Modem.


Positive experiences

In the last few months, a number of activity competitions (challenges or contests) have been held. However, after initial reservations, these activities and the way they were conducted were viewed positively by the majority. Due to further requests, we have now decided to designate a suitable frequency range on QO-100 for such activity competitions, which allows a more orderly and undisturbed coexistence of supporters and opponents of such competitions.

The “unwritten” law

Until now, there was an “unwritten” law that, as a matter of principle, no contests should be carried out via satellites. Some still know it as lore from the early days of OSCAR satellites almost 50 years ago! This had technical reasons, some of which are still valid today. For example, previous OSCAR amateur radio satellites and also CubeSats tend to have very limited resources, i.e. low bandwidth, small batteries and low-power solar cells. Excessive load on the linear transponders, for example, repeatedly leads to unplanned shutdown in OSCAR-7. AMSAT-NA has reconfirmed this upon inquiry and still does not wish to have contest operations over AO-7.

We are in a more fortunate position with the first QO-100 AMSAT geostationary transponder on the Es’hail-2 satellite. Again, we don’t have unlimited resources at our disposal, but with large powerful solar generators and higher battery capacities, we are much more relaxed. LEILA will also help if someone is using excessively high transmitting power.

From a technical point of view, there is therefore currently no reason to prevent contest style operation, albeit within a limited scope, on QO-100.

We expressly point out that each owner and operator of an amateur radio satellite owns the house right, as by the way with each terrestrial repeater also. Therefore, each operator decides for himself whether or not to allow contest operations on his amateur radio satellite. In case of doubt, the permission of the respective AMSAT organization or the owner of the satellite should always be obtained beforehand!



With this decision we hope that this will also contribute to an increase in activity on QO-100 and broader interest among radio amateurs in the QO-100 footprint.



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