Having upgraded to an SDRplay RSPduo, here is a typical result from the overall M2 receiver system here at G8GKU, system details may be found below the image.

M2 Image, please see information below

APRIL 13 2019
10:30 am.
North to South pass, over UK.
137.910 MHz +- Doppler

RECEIVING SYSTEM, from aerial inwards ….
AERIAL, crossed dipole 4 element turnstile, RHCP
PRE-AMPLIFIER, 24 dB gain ca 0.6 dB N.F.
SIGNAL FEED, 12 Meters coax, low loss double screen.
AMPLIFIER POWER, 9v @ 100 mA, bias T to coax
BAND PASS FILTER, 137.5 MHz, double tuned
POST PROCESSING, AUDACITY, re-sample to 192,000

All trademarks and software names gratefully acknowledged.

Satellite image pager interference

Although many satellite images are captured with little or tolerable degradation, due to the effects of near band or in band pager interference, some images are more badly affected. This image received from Meteor M2, June 20 2017, orbit number 15301, 11:00 hours, 137.900 MHz, shows the effect of both in band and near band data transmissions from local, ( Oxford, UK )  high power pager style systems.

Meteor M2 UK, Europe, June 20. Orbit 15301


Orbitron DDE Azimuth Elevation To Serial

Control a satellite rotator automatically from Orbitron by sending it the azimuth (or other properties) via serial.

A while ago I wrote some code to listen to Orbitron using it’s DDE inter-process comms and send the satellite information string over serial to potentially drive an aerial rotator.

I’ve since updated the code and thought I would share it here.

Using DdeOrbitronToSerial

  • Firstly install Orbitron.
    • Update 13-02-2019: Orbitron doesn’t seem to work well unless you run it as admin – it can’t save files to its install dir and won’t pick up config changes. One work-around may be a custom install location.
  • Download (June-2019) and unzip it to somewhere sensible.
  • Open the install directory of Orbitron and find Setup.cfg (example path below)
    • C:\Program Files (x86)\Orbitron\Config\Setup.cfg
  • Add a similar line as below to Setup.cfg: (obviously changing paths to where you unzipped things) As per Orbitron’s documentation:

    List of available drivers. New drivers can be added by editing [Drivers] section of Config\Setup.cfg file. Example config line: MyDriver=d:\MyDriver.exe

  • Don’t directly run the exe, you have to launch it from Orbtron itself by going to the rotor/radio tab, selecting the correct DDE driver, in this case it’s DDEOrbitronToSerial. Then click the button to the right of the dropdown to start sending data and launch the application:


  • The DDEOrbitronToSerial application should now launch and you will be able to select your COM port and output the satellite data to the serial port.
    • NB: You can edit additional options such as com port baud rate in the config file by clicking the open config button.

Any bug reports or feature requests are welcome!


  • June 2019 – Added latest release with a bug fixes:
    • FIXED: Certain USB to serial chips would only receive a few characters.