Dish / Antenna Alignment

  • Hello everybody,

    I'm having problems to make a correct alignment with my 80cm dish; i followed the info from Satlex indicating elevation angle to 27 degr. but i can not receving nothing with that elevation; i can receive something at 43 deg.!

    I'm based in the NL ( Leiden); can anyone, maybe from NL, give me why this happens, and any suggestions to solve this issue.

    Thanks

  • Hi All,


    As a quick update, I seem to be making some progress now, I have managed with my Triax 1.1m dish (and a Technomate Satellite DVB-S box) to align to Astra 19E and fully decode FTA TV. I then moved slightly East and can now lock to Badr3/4 and am receiving signals ok.

    the issues i appear to have had, first, the elevation calibration on the back of the Triax dish is easily 8-10 degrees out, and for whatever reason the compass apps i have used were also not accurate..!

    Now I'm locked to Badr3/4 a couple of questions:

    - would i be able to receive Es'hail Sat 2 from this position ? (with 1.1m dish)

    - second, in the current position, what would be the manual settings to enter into the Sat DVB-S box to lock to the Es'hail Sat 2 wide band transponder TV beacon - and i can see it this receivable...?

    Many thanks again for any tips / help here...!

  • The way I got my azimuth correct was to use the Sun. I worked out for a period of a few days when the Sun would be the same azimuth as the satellite and used that time to ensure that the shadows of the feed were in line with the rest of the dish. Then I only had one degree of freedom to worry about.


    If you have already received Astra 19E and BADR then you will know the elevation calibration offset, so use that information to set the correct elevation of the dish beforehand.


    Once you have the system on the correct frequency for the NB transponder, I found aligning the dish to be easy, it is a string signal even with some off pointing.

  • That solar method won't work is you live in the North West, or at least only rarely. If you find the elevation calibration is out it may mean the feed is not located at the correct focus. This can happen if the feed is modified to fit 2.4 GHz.


    Mike

  • G0TKZ Triax dishes for our region have an intrinsic offset of 26 degr so that everybody is able to point his/her dish (at the camping site). So, if the dish is perpendicular (90 degr) compared to 'flat' ground the elevation angle is 26 degrees. That means that at your location -where you need 26.5 degrees elevation- the dish almost has to be perpendicular to the (flat!) ground.


    Take that as a starting point (don't look at the 'degree table' at the sides (because they -mostly- have two variants , depending on your lattitude) and then turn your dish to around 148 degr azimuth (somewhat more South compared to SSE). If all other equip ment is working properly you must be able to see something on Es'hail-2. Then it's a matter of refining and tweaking for the optimal signal strengths / SNR's. It helps when you are able to listen to the NB tpx and monitor the beacons.


    Bear in mind, the bigger the dish, the more precise the pointing/alignment (due to smaller opening angle(s).

  • Thanks guys for the follow up..!

    Any ideas what the manual settings would be for the DVB-S box to receive the wide band TV beacon from Es'hail Sat..?

    cheers...!

    None - it will not work as the Beacon is DVB-S2. Most boxes these days are, if your is then set the transponder frequency appropriately, set 2Ms and search. For this to work the LNB has to have been modified to a lower LO so that the IF falls within its' frequency range. With a standard LNB the beacon will be below the minimum 950MHz tuning range of standard boxes.

  • The Sg LAB transverter is installed very close to the Kenwood TS 790E. However, the connection to the helix antenna takes place with 30 meters of RG 213 cable. It is essential to adapt the power output of the transverter to the RG 213 cable, otherwise the ros is very high. I solved the problem by inserting a stub at the output of the transverter to adapt the impedance to 50 ohms. Certainly 30 meters of RG 213 introduce a loss of 13.41 dB, but the output power of the transverter is 2 watts. The output power of the 30 meters of RG 213 cable is 91 mW. This power enters correctly to the power amplifier connected to the helix antenna. 73!