MER vs. Dish Size?

  • Hello YLs and OMs,



    I am looking for some real life MER figures that can be achieved with a certain dish size.


    I found this table here on https://wiki.batc.org.uk/Receiving_Oscar_100_DATV_signals:



    This table is valid for the old 2 Ms QO-100 DATV beacon A71A. There are also a few discussions on the net. but those I found all discuss the values for the 2 Ms transmission. Have these values changed after the beacon bandwidth has been reduced to 1.5 Ms?


    What are typical MER values you get with your own setup?


    I need some guidance to optimize my setup and to know what to aim for.



    Thanks and vy 73


    Holger ‚Geri‘, DK8KW

  • The best I can receive the DATV beacon when completely empty of activity and a good clear sky is 10.4 MER on my 1.05m offset dish, I spent some time checking it for alignment and that was the best I could get. The software I use is Longmynd, I use a POTY feed and a standard crystal'd LNB .

    One extra thing I have in there is a 749 ish MHz is bandpass filter to reduce the front end noise window slightly to the Minitiouner-express. I think that when tested it gave me a 0.5dB improvement in MER with it to without it. One other station on the SAT at present, cloudy sky and I am at MER 10.0. So for my best guess with a similar size dish and standard LNB no filters would be at MER 9.5 and you would have a good RX.


    Adrian

  • Hi,

    Maybe these values are possible as I am more near to the center of the satellite beam. Stations for example in Italy can confirm that. Always values are taken when NO other activity exists on WB. I use minitiune and DATV express receiver. On NB for example me and SV8QG can have max 40 dB SNR on CW beacons on SDR console using about 90cm dish sizes or slightly more.

    Update: all these values are with out POTY !!!