• This window is used to adjust your radio's TX (uplink) and RX (downlink) frequency to compensate for the Doppler effect (the apparent shift in frequency of a wave due to the relative motion of source and observer). Doppler shift is calculated in accordance with Kepler's laws.
  • Enter the satellite uplink (your TX) frequency in the Satellite TX field.
  • Enter the satellite downlink (your RX) frequency in the Satellite RX field.
  • Select the VFO you will use for TX and RX (see rest of this section).
  • If you are using a transverter select the Options tab and enter the transverter offsets.
When you are tuning remember that the important frequency is the satellite frequency, not the frequency on your radio. The frequency on your radio is the satellite frequency corrected for Doppler shift.


A plot of the selected satellite‟s position and footprint. Use the plot offset buttons to offset the plot time.



Infrequently used options are located here to avoid cluttering up the display.



Swaps TX and RX frequencies.


Copies TX frequency to the RX.


Copies RX frequency to the TX.


Displays pass details using the default text editor, useful for programming memories in a handheld UHF/VHF transceiver.

For example:



Reloads the latest Kepler data.

Doppler – the current frequency correction.
Transverter – if you are using a transverter enter the correct offsets here and check TX and RX as appropriate.

The satellite‟s page in (if available). Note: not all satellites are supported yet.
This is a useful way of getting information about satellites modes and frequencies.


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