This page allows you to select a satellite and observe the downlink satellite spectrum. You input various parameters and after a while an image will return of the satellite spectrum requested. The whole system has taken several months to build and this web page first worked 15 May 2007.

The lower left corner shows a long number, representing the time in seconds since 1970, plus the wanted satellite position plus the actual final satellite position from the antenna position encoder, which may differ slightly, depending on where the antenna drive motor finally stops. You can try looking for other satellites in between or peaking up slightly with slightly different positions.
27 Oct 2007: There used to be a compensation for a 5 dB peak to peak ripple. My corrections for this have drifted out of sync and the corrections were removed this evening. Really I need a better quality LNB, with PLL so it is accurate in frequency as well. The ripples in the cable must be due to some termination mismatch problem or regular kinks in the cable.
9 Nov 2007: I have made the image black on white to save ink when printing.

Satellite spectrums

Please think carefully before use. At present it is confined to:
● Operation in the frequency range 10700 MHz to 11700 MHz. Choose a centre frequency and span that fits within this range. It is technically possible to see signals up to 12650 MHz but this range is not calibrated.
● Status = Operational 4 May 2008.
Receive polarisation = Nominal Vertical.
Email me eric@satsig.net if you want it changed.

Input your wanted satellite frequency spectrum selection and wanted satellite to view. The antenna is slow and takes about 1 minute to move 16 orbit degrees, plus up to 30 seconds for the spectrum analyser sweep.

Satellite positions to try:
7E W3A       607
4.8E Sirius    595
1W IS10-02     564
5W AB3      545
7W Nilesat 529
8W AB2      524
                  495
15W          Telstar 487
18W 342E IS901   472
22W 338E NSS7   449
                   405
                   205 (el=0)

53E AM22 Sesat 858
45E Intelsat 12     812
42E Turksat          796
40E RSCC AM1    785
39 Hellasat   780
33E Ebird     750
28.5E EuroB 728
26E PAS5    715
23.5E Astra   700
19.2E Astra   675
16E W2        659
13E Hotbird   640
10E W1        624

Please contribute to forum discussion about this page.

Note the orbit positions and satellite names may be wrong. Moving from one nearby satellite to another will reduce the time of the antenna movement.

This page provides access to an on-line spectrum analyser HP8560A connected to a steerable 90cm Ku band antenna, at approx 52 deg North latitude and 0 deg longitude (in the UK, Europe, near the Greenwich longitude meridian). It is possible to point the dish at satellites over the Atlantic, Europe/Africa region and Indian ocean, eventually to approx 70 deg west and 70 deg east longitude along the geostationary arc. Please note that it takes about 7.5 minutes minutes to re-point the antenna from one extreme to the other, so please be patient. The antenna is presently at ground level so I can make adjustments and does not yet therefore have full visibility of the geo orbit. The satellite frequency spectrum is drawn based on input data that you need to supply. You need to know the downlink frequency and the span (width of the screen display). make the span wide enough to see your carrier. Frequency accuracy is only about +/- 1 MHz, due to temperature and initial error, at the moment. A suitable resolution bandwidth, sweep time and video filtering bandwidth is determined automatically.

I have put this together at home and not everything works. You are welcome to email me eric@satsig.net but don't expect an immediate response. If the system stops it may not be fixed for several days. Do tell me however, sometimes the disk just gets full and I need to delete some old spectrum plots or log files. At the moment the present operating LNB has a local oscillator frequency of 9.75 GHz. Polarisation is set to Receive Horizontal or Vertical - see the current status line in red near the top of the page. Ignore polarisation the selection option in the url parameter string. 10.7GHz is down-converted to 950 MHz, 11.7 GHz is down-converted to 1950 MHz. The default satellite spectrum centre frequency is 11.2 GHz and span 1000 MHz. Each horizontal division is 100 MHz wide. The vertical scaling is 5 dB per division. There is no transmit BUC, so it is quite safe to use and won't cause interference to satellite services.

Thanks and Credits: This spectrum analyser project involved several contributions:
Credit goes to gd software , cgic software : see background to this spectrum analyser project for formal software credit statements.
gcc software. Hewlett Packard. National Instruments. ByVac.

Please note that all spectrum image files are saved. Selected examples are here satellite spectrum plots for Europe

Other links: Satsig forum posting asking why you need to input a satellite carrier frequency to a spectrum analyser in order to find a satellite

Spectrum analysers for sale (advertisement) Spectrum analysers for sale

Frequency spectrum of a satellite TV DVB-S type carrier Transponder frequency spectrum for Eutelsat 16E satellite

Some old frequency spectrum plots for satellites visible in the geo orbit from Europe