HELI2400

  • I did not try the HELI2400 antenna, but did see the very nice construction for real several times now (last time, they were all sold out..) I do not have any connection to this supplier, but you can be sure to buy quality. I do have some other ANJO antenna and these have a high mech. standard and good RF performance.

    When I would have problems with installing a dish, this antenna would be my 1st choice ( OK, it is not cheap but I would consider the investment).


    73 Ed PA1EW

  • PA1EW Hallo Ed,


    i have this antenna. It's a very nice construction. With 5W and 4m Ecoflex 10 working in SSB over QO-100 is not possible. Perhaps the place I installed the antenna is not good.
    Therefore my question how many watts are necessary for uplink with this antenna.

    73 Hans-Jochen

  • Assuming the direction to the satellite is correct, 5W and 22dBi should work nicely. So either you don't have 5W or the antenna is not 22dBi.


    there is nothing to add...

    just use a 65cm dish with G3RUH and you will be happy. There are so many busy contributors here. Rarely active on the xponder


    Greetings from Vienna - (portable equipment not ready yet)

  • I would say there is something wrong with your output-power or antenna-gain or cable-connection. In addition as already mentioned before the antenna is not the cheapest. My construction is 15€ and works well for TX and RX with one reflector. I would use this solution if a dish can be mounted in your environment.

  • How much power do you run? I tried something similar with 20W and was less than impressed by the resulting signal on the transponder. The squint angle between LNB and helix is probably too large at my side.

  • DK1MG Hello Hans-Jochen, as said by others 5 ... 10W should work alright with a 22dBi antenna. I can't find a reference to either LHCP or RHCP polarisation for it?. It must be RHCP of course, but I am almost sure this is correct.

    Another problem to look for is the N-connectors used on your cable(s). Any small error in mounting will cause a lot of extra attenuation at 2.4GHz. Could be a good idea to measure the cable(s) on a good SWR-analyzer.
    Do you know the antenna SWR with coaxial cables connected?. If not, measure- or ask someone else to all this do for you... Wishing you good luck!

    73 Ed PA1EW

  • How much power do you run? I tried something similar with 20W and was less than impressed by the resulting signal on the transponder. The squint angle between LNB and helix is probably too large at my side.

    I use 8-10Watt at the Helix connector and it works well with strong signal and 80cm Pollin dish. For S-Band the focuspoint is not so critical in compare to Ku-band. I optimized it a little bit by downtilt the Helix towards the dish center. Same signal strength in compare to a WLAN barbecue grid antenne i used before.

  • Hm.. let's do some math. The offset is around 10cm to fit next to the LNB and the lever arm (focal length) of a f/D=0.7 is 80*0.7=56cm. So the angular offset is arctan(10/56)= 10 deg.

    According to G3RUH (60cm dish) a 60cm dish has a -3dB beamwidth of 16 deg, so 8deg offset is -3dB. The 80cm dish should be more focused and we are 10 deg off, so I would at least expect -5dB or ca. 1/3.

    So your quoted 8-10W fits nicely with the 2-3W I was hoping for with a perfect setup.

  • So please, my dear friends, even if we are just amateurs, our goal should be to reach our opposite with the main lobe of our transmit power to be as effective as possible with radiant power ...
    And that includes clean radiation characteristics of our antenna systems ...

  • At least that is my own goal. So after some brief testing, I canceled the idea of using a helix next to the LNB in my 88cm. I still have an AO-40 Mode-S G3RUH dish .. its 60cm with the genuine G3RUH patch feed optimised for it should be superior to the 88cm. But once set up, I can do easy comparisons.

  • DD4YR and DH2VA , I fully agree... we should always reach for the best, improve and don't waist energy (entropy)..


    Here is the secret picture of my original famous 60cm G3RUH dish and patch in the shower... a few weeks ago,.. it produced a clean RHCP signal after I incidentally hit the shower controller ;-) I found the dish left forgotten in the basement since OSCAR-40. It worked very well.. but only with opened window.. :-)




    Indeed.. just for completeness.. my receive dish was already installed in October before the launch of Es'hail-2 and has a motor. I'm waiting for good weather AND time to either install a second dish or use a Dual-Feed with patch and LNB.

    Peter Gülzow | DB2OS | AMSAT-DL President | member since 1983 | JO42VG

  • Hm.. let's do some math. The offset is around 10cm to fit next to the LNB and the lever arm (focal length) of a f/D=0.7 is 80*0.7=56cm. So the angular offset is arctan(10/56)= 10 deg.

    According to G3RUH (60cm dish) a 60cm dish has a -3dB beamwidth of 16 deg, so 8deg offset is -3dB. The 80cm dish should be more focused and we are 10 deg off, so I would at least expect -5dB or ca. 1/3.

    So your quoted 8-10W fits nicely with the 2-3W I was hoping for with a perfect setup.

    Achim, i had the same antenna directly in the focuspointpoint before and I was not able to measure the delta in uplink between solution-in-focus and solution-out-focus. Maybe (if time) i will analyze it with FEKO and present the graphs here to now the exact values. To measure this via the transponder is difficult.

    The only dis-advantage was the decreasing of the downlink signal with in-focus but this was expected before.

    See both solution depicted below.