Posts by DD5ER

    Hello Robert

    in the upper picture the GPS module is wrongly plugged on the downconverter. It must be rotated through 180°.

    Also check the connections from the LNB to the downconverter that the ref. frequency output ( WB in ) is connected to the correct output of the LNB. Because with our mod. LNB is the connection the other way round.


    73 de Michael

    The Opticum Twin LNB LTP-04H up to the S/N: 18-08-0 xxxxx is in any case easy to modify.

    For the S/N with 18-12-0xxxxx and 19-01-0xxxxx we are currently investigating whether a modification is possible with reasonable effort.

    At the moment we still have a larger quantity of the LNB LTP-04H from the 18-08-0 series, which are now being modified. We ask for some patience here

    We assume that the RX/TX stations are stationary and not moving. The things that now influence the Doppler are the rotation of the earth and the satellite movement in space in relation to the earth and its movement. At 10 Ghz there are also influences of the atmosphere which can cause a Doppler shift. The Doppler shift changes evenly over the day, mainly due to the drift of the satellite in space. Erratic changes normally only occur during orbit corrections by ignition of the engines for orbit correction. Geophysical events (earthquakes, tsunami etc.) can also lead to a sudden Doppler shift. The measured amount of the Doppler shift depends on the position on earth in relation to the satellite. This means that different values are measured at the same time at different places on earth. For this consideration I have assumed that Rx/TX on earth and in the satellite have no drift. A drift of the RX and/or TX influence the Doppler shift in positive and negative direction. This results in a very complex system,


    73 de Michael