2.4m offset dish - is multifocus doable?

  • So I have a new Prodelin 2.4m and I would like to do a multifocus setup for 36E and 28E. When I tune in 28E in focus, I get approximately 10dB on the UK beam, so I can afford to lose some 2-3dB and still get most of the UK beam with 36E in focus and 28E on the side.


    In C-band with PF dish, it would work but now I have some doubts about achieving this in Ku band with an offset dish. I can see that the 28E LNB would need to be quite far away (20-30cm) from the in-focus one and so far I wasn't able to get any useful signal out of this. I don't have a proper holder yet but I don't know if I even should try building one.


    So I'd like to ask someone with more experience with Ku band and offset dishes - is multifocus doable on a 2.4m offset dish for satellites 8 degrees apart?


    Thanks!

    Location: 50N, 14.6E (near Prague)
    C-Band 37.5W-55W: Channel Master 2.4m PF, AVCOMM OMT & Ring + 2x Astrotel 15K, circ.: AVCOMM polarizer + ESX242 (6° off)
    C-Band 34.5W: IRTE 1.8m prime focus, ESX241
    Scans done with TBS 6903

  • I suppose you want to catch thae Russian packages from 36E on Express-AMU1.Since the satellite went into operation,the signal in the east of Europe has improved significantly,so with my antenna T90 I'm picking up these packages.I have also been able to make lnbs support which mounted on a 90cm offset antenna I could receive DTH packages from 19.2E, 13.0E, 4.9E, 1.0W and 4 / 5.0W.
    So,in principle you can catch those two satellites at a distance of 8 degrees apart,but I just don't know if the result is the same with a big offset antenna,especially on a satellite with a problematic signal,such as 28.2E,which in your area is not DTH?
    But no matter how the situation might be,I,if I were in your place,I would try to set up feeds for the two satellites.It costs nothing but extra work...

    7 antennas,including 2 of 150cm,one T90 with 16 lnbs
    lnb:Inverto Black Ultra with scalar rings and many Ku lnbs,
    C-band LNB:ESX241,Galaxy Inovations,EuroStar,MTI 20K,NS741U C/Ku,Inverto Single C-band Flange,lnb Chaparral Servo Motor & Skew Control
    LNB Ka:R9216DF XWM,Hughes FSS 19.7-20.2 GHz,
    6 satellite receivers,2 Meters,
    7 PC cards(tbs6983,6903,6590,6522,6209,2603,6909X,6903X,6504),3 tuners usb-tbs5927,tbs5925 & SkyStar USB 2 HD,
    Satellite reception between 100.5E-50.0W,
    Loc:Romania :3:

  • To get both 28E UK beam and 36E Russia beam, I would normally need a 1.8m dish, which gets me 80% of transponders. Now I have a 2.4m dish and I was hoping to be able to get both 28/36 but so far it seems unrealistic, so I'm looking for experience of other users with offset dishes. Prime focus might be better for this since I have no issue getting 40W and 47W in C-band with a multifocus LNBs, losing only about 1.5dB on the off-focus LNB.

    Location: 50N, 14.6E (near Prague)
    C-Band 37.5W-55W: Channel Master 2.4m PF, AVCOMM OMT & Ring + 2x Astrotel 15K, circ.: AVCOMM polarizer + ESX242 (6° off)
    C-Band 34.5W: IRTE 1.8m prime focus, ESX241
    Scans done with TBS 6903

    • Offizieller Beitrag

    At first, congratulations drhans to your new toy!


    But I must say, I have no Multifocus experience on such dishsize, only on T90 and 1.2m dishes, sorry I can´t help. :79:


    Best Regards
    qwer.


  • I come late with my answer, but I come....... :26.


    its realy so, a PFA dish is better suitable to get a multifeed reception. So I tryed it on a laminas as 1800. I catched the front of the feedarm and mounted a normal multifeed set. It was indeed difficult to reach the correct distance to the focus. But the next problem waited for me: the small opening angle. I tried to receive 28,2 and 42 east.

    I had to learn that this distance of 14 degree dasn't allow a good reception.

    I think its the same for examble to receive 28,2 and 36 east. I put 42 east in the middle but I lost the uk-beam on 28,2 east. at least I completed 42 east with 46, 39 and 36 east (europ. beam). mostly my dish has 26 east in the middle, near by 28,2 and 30,9 east. so the uk-beam is complete but 11056 V 30000 on 30,9 east has a small signal, 11095 V isn't possible, the opening angle allows no better reception.

    the efficiency of the dish changes in a distance of 4 degree from 180 to 150 and 125 cm. so my experience, regards. :3:

    1 Lam. 180 stationäry on 26 east

    1 Gib. 150

    1 T90
    1 Gib. 125
    all together in multifeed with 28 lnb

  • I believe that multiple feeds from multiple positions on a PFA antenna are not a solution, no matter how big. Symmetrical was and is designed to have a high directivity and therefore is used for the reception of complex signals. Offset has the advantage that it has more focal lengths and can be exploited.

    Toroidal is the product of an offset, and the reverse is true. They are both expressions of the same geometry.

    7 antennas,including 2 of 150cm,one T90 with 16 lnbs
    lnb:Inverto Black Ultra with scalar rings and many Ku lnbs,
    C-band LNB:ESX241,Galaxy Inovations,EuroStar,MTI 20K,NS741U C/Ku,Inverto Single C-band Flange,lnb Chaparral Servo Motor & Skew Control
    LNB Ka:R9216DF XWM,Hughes FSS 19.7-20.2 GHz,
    6 satellite receivers,2 Meters,
    7 PC cards(tbs6983,6903,6590,6522,6209,2603,6909X,6903X,6504),3 tuners usb-tbs5927,tbs5925 & SkyStar USB 2 HD,
    Satellite reception between 100.5E-50.0W,
    Loc:Romania :3:

  • @ Turksat Uzmani wie läuft bei Dir die Einstellung Deiner 240er. Wie kommst Du voran? Schwergewicht auf 30,9 oder 42 Ost gelegt? Grüße Kleinraisting

    1 Lam. 180 stationäry on 26 east

    1 Gib. 150

    1 T90
    1 Gib. 125
    all together in multifeed with 28 lnb

  • @ Turksat Uzmani wie läuft bei Dir die Einstellung Deiner 240er. Wie kommst Du voran? Schwergewicht auf 30,9 oder 42 Ost gelegt? Grüße Kleinraisting

    Sorry Dieter, Habe es total versäumt dir zu antworten.

    Also folgendes, die Laminas 2700 wurde versetzt und auf 42*Ost ausgerichtet.

    Die ersten testergebnisse waren heute zu meiner Zufriedenheit. Alle Eastbeans einschließlich 11958 V sind empfangbar. Was fehlt sind die Türkeibeams, ich hoffe da werde ich noch fündig...

    Muss dazu erwähnen das bei meiner laminas Invacom Flansch Quad mit original Laminas feedhorn gar nicht harmonieren. Erst mit Inverto und später mit Octagon Universal Twin LNB erzielte ich Erfolge.

    Folgende Werte wurden vorab erreicht.

    12054 H 16 dB

    11958 V 8.6 dB

    12015 H 7.7 dB


    Sorry Dieter, it has totally missed you to answer. So the following, the Laminas 2700 was set and geared to 42 * east. The first test results were today to my satisfaction. All Eastbeans including 11958 V are receivable. What's missing are the Turkey beams, I hope I'll find it ... Must mention that with my Laminas Invacom flange quad with original Laminas Feedhorn do not harmonize. Only with Inverto and later with Octagon Universal Twin LNB I achieved successes. The following values were reached in advance.

    12054 H 16 DB

    11958 V 8.6 DB

    12015 H 7.7 DB

    Grüsse /greetings

    Hüseyin

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