Today, sumbandilasats radio amateur transponder and parrot repeater were secretly tested over Delft. After a scheduled mode change to turn them on, we tested the parrot first and after that the transponder. The tests were carried out by Johan Erasmus – ZR1BMD, Wouter Jan Ubbels – PE4WJ and myself (Wouter Weggelaar – PA3WEG). Wouter Jan was at home on his balcony with a hand-held transceiver and a whip antenna. Johan and I were in the Delfi-C3 groundstation. The transponder expects FM narrow on the uplink and is best received FM wide on the downlink. Some more tests are needed to determine the precise audio behaviour. Two recordings made by the primary and backup transceivers can be found here:
Please note that on the primary recording, the receiver was not tuned after parrot repeater operation and therefore is not correctly centered at the rest of the pass.