Passband Centre

  • Using SatPC32 and despite reading the manual and trolling the internet for an answer I've been unsuccessful.

    When tuning around the passband (and outside by mistake) of a given satellite and wanting to return to the centre, how do you know what frequency the centre is? Am I missing some basic setup option.

    Also what is the recommended ERP to throw at these satellites?


  • Trolling the internet? I hope you meant Trawling. The nominal transponder edges are defined in the config files where you set up each satellite. The actual centre frequency is not a parameter but you can work it out from upper and lower. To find it during a pass you will need to compensate for Doppler. The offset is displayed in real time.

    Unfortunately, not all amateur satellites carry frequency standards and drift quite a bit with temperature. Consequently it can be really difficult to know where the centre is.

    ERP - None at all until you receive the beacons, then the minimum to hear yourself come back, but never ever more than the beacon. In practice a watt or two to a small yagi is sufficient.


  • Thanks for the reply Mike, yes I meant trawling. What I mean by centre is a starting point, the SatPC32 takes care of the doppler, but its when tuning about its easy to get lost and its a quick way back to the starting point +or - doppler. I didn't write the config files, just using whats there.

    I take your point about ERP.