Info on frequencies here.
I think they also have a backup frequency that is not published. They have had interference on both uplink and downlink in the past possibly accidentally. The exact time of school contacts and normal downlink frequency is usually very well advertised in the country where the contact will take place.
Sometimes, including one recent contact in Italy they actually re-attempted the contact at the next pass 90 minutes later as there was interference. They try throw lots of power and gain on the uplink in an attempt to drown out any accidental or low power interference.
On 06/04/2015, Daniel Estévez [email protected] wrote:
El 06/04/15 a las 17:12, John Brier escribió:
fwiw, I do know not to interrupt during scheduled ARISS contacts. I was telling someone else who responded to me that it was a good thing they don't publish the uplink frequencies not only so people don't intentionally try to take advantage of the situation, but also so ignorant (and excitedly blind people like me) don't interfere.
Sorry if this has been asked before, but are not the uplink frequencies 145.20 for region 1 and 144.49 for regions 2 and 3? Or do they use different uplink frequencies for scheduled contacts?