NB Station Description and User Reports, Statistic

    • Official Post

    Thank you all for a mostly well behaved day 1!

    Please send in user reports with the following information (if available):

    • RX antenna diameter
    • NB noise floor increase
    • TX antenna diameter
    • SSB RF power


    We are trying to determine the useful uplink power as some stations are using way too much of it. This will help us in fine tuning the settings and improve performance for all.


    73 de Doha!

    Achim DH2VA


    PS: we are getting any news out as fast as we can but we are only three persons here (DB2OS, DG5NGI and myself) and we can either work or post.. :)

  • Hi Achim


    I will try to make some measurements today. Power here yesterday was in the region of a few hundred mW to 3m dish. I'm planning to add a coupler/power meter at the dish to measure it.


    It was a very interesting day yesterday! 12 QSOs on SSB and also decoded myself with power backed off at least 16dB with FT8, QRA64D and JT65A.


    73


    Charlie

  • I am receiving with 80cm dish, SR-3602 LNB and SDRplay RSP1a SDR using gqrx.

    Transponder noise is about 11-12dB above noise floor.

    Stations that are shown peaking 15dB above transponder noise in the SDR are very comfortable to copy, 10dB is enough for Q5.

    Indeed some stations have 20dB or more which is unnecessary.

    Uplink still has to be mounted, I am starting with 40-el yagi and 2 watts via 10m cable.

  • Hi Achim,


    got my feet wet with this experimental setup:


    RX antenna Diameter: 80cm dish offset, GPS stabilized octogon LNB

    TX antenna Diameter: Linear Antenne, Horizontal, 18 dBi

    SSB RF power: 10 Watts pep

    Tx Setup: SdrAngel (Linux) + AdalmPluto (TXCO Mod) + pre Amp + final Amp

    Rx: straight SDRSharp on stabilized RTL Dongle

    Very exciting and never had so much fun conducting a qso, great work! :)


    ciao lg Robert, 73 de oe6rke

  • This morning, 06:30 UTC, empty transponder (I´m alone...):

    RX:

    QRG 10.489,798,

    1,5m solid dish, PLL LNB GPSO, LOF 9.200 MHz,

    noise floor NB 17dB above ground noise (-43dB / -60dB)

    SNR 34,6 dB on SDR-play, with


    TX: 5 Watt, 1,2m solid dish, 2,5 turn helix feed


    TX/RX SSB/CW Equipment FT-736R


    Yesterday afternoon with a lot of traffic on transpoder (very strong stations) i think the signal was 6-10 dB weaker. (I did not measure). Is any AGC on the transponder active?


    73´s de Robert

  • Hi !


    RX & TX 2.3m dish with coaxial cup feed (dual band), estimated gain 33 dB


    NB noisefloor 12-14 dB above my own noise


    SSB power 20 dBm - got report of good readability


    CW power 13 dBm used during QSO . I could not go below 10 dBm now.


    Tnx for all work with QO-100 !

    73 - Hannes - SM6PGP


  • Yesterday afternoon with a lot of traffic on transpoder (very strong stations) i think the signal was 6-10 dB weaker. (I did not measure). Is any AGC on the transponder active?

    I saw a couple of times that stations transmitted so much power that the AGC kicked in. It was immediately visible because the color of the background noise in the waterfall changes. I'm not sure if there already is AGC action before that effect is seen.

    It will be helpful when the beacons are enabled so everyone has a reference for their signal strength, there were a couple of stations that were quite strong compared to average but of course it is difficult to complain as long as it is not yet established what is "too strong".

  • I saw a couple of times that stations transmitted so much power that the AGC kicked in. It was immediately visible because the color of the background noise in the waterfall changes. I'm not sure if there already is AGC action before that effect is seen.

    I´ve watched the same and thougt first that something wrong with my reception equipment ... looked horrible on the waterfall ...

  • No TX on this side,

    Locator KM69

    RX is with 60 cm offcenter dish. Octagon OSTLO (not modified)

    RTL-SDR (green one )

    About 10meters coax between LNB and SDR


    Carrier is 15 db above noise level.. Easly reading 20-25 db over SNR for most of the stations..

    Easly copied all stations that i see on display.. Even a station that has 1W over a wifi antenna..


    I also observed some stations kickin AGC on

  • It appears that the majority of stations receives with an SDR or at least has the capability to look at an SDR on the side, so I expect that once there is a good reference and understanding of the proper level the situation will be better than in the old days when everyone heard only their own signal and could not easily compare with others.

    (it also helps that the downlink signal is so strong that there is no need to make extra power to hear oneself due to local interference on receive)

  • Call: PY2SDR (Edson)

    QTH: GG56tv (São Paulo state, Brazil)

    RX antenna diameter: 1.2m offset

    NB noise floor increase: 10.5 dB

    TX antenna diameter: 1.2m offset (being prepared)

    SSB RF power: 1W (being prepared)

    RX Rig: Octagon OSLO (unmodified), SDRPlay RSP1A, SDRUno

    TX RIg: SDRAngel, PlutoSDR, WiFi driver amp, WiFi PA

  • Feb.12th between 15:32 and 19:51 some 20 qsos, 3 in CW. Lowest pwr DL4SAC with 200mW to a 40 turn helix.

    There was at 17:56 F5JWF with excessive pwr, blocking and desensing the whole transponder passband. After friendly requests to him to reduce pwr by 20 dB he decides : i go QRT now

    All other stns excellent, OE4WOG had problems with the downlink.

    Here FT-847 fully DUPLEX with 145 to 2400 and RX Kuhne LNB to 1123 MHz divider port 1 to SDR port 2 to a converter for 430 MHz. Operating full duplex and in parallel watching my SDR.

    TX dish 60cm G3RUH patchfeed, RX 1.40m dish.

    Suppose that 10W at dish is quite sufficient-

    for Ascension 80cm should be ok.

    DK2ZF Feb. 13th 09:47

  • Achim


    I have measured TX power here now. To get a comfortable but not excessive signal back, I am running about 200mW into 1dB loss to the feed with 3m 0.3 f/D dish dish and 2.25t helix feed.


    Transponder noise is now about 15dB - seems less than yesterday, but I may not have the 10GHz feed exactly at the focus.


    Testing now with FT8 running 200mW is showing decodes at +7dB S/N


    73


    Charlie

  • I am using an Octogon OSTLO LNB (unmodified) and an offset 85cm x 70cm dish orginally used on 20GHz. Receive is LimeSDR mini and Rigol spectrum analyser. Currently I have no transmit capability but planning to use the same dish if possible.


    NB transponder noise is 11dB above receiver noise. Largest signal received is 17 dB above transponder noise in 3kHz bandwidth but most are about 10dB above noise


    I am very impressed so far.


    Mike G4CDF (IO91NK)

  • I am using a 60cm offset feed dish for TX and RX with a G0MJW dual band feed.

    Transponder noise is around 6dB above the noise floor.

    Transmitter power of 10W gives me a similar signal level to most other users.


    I am sure an even smaller dish would still be usable.

  • RX 130cm Offset + Octagon unmodified with software drift correction : 17db NB TP Floor. Fully sufficient.


    TX 80cm Offset + 4 winding Helical feed @ 20 W : abt 4db weaker than the most other Signals (Maybe Helical is not properly mounted in the feedpoint, will check that soon)



    vy73 DB8TF

  • RX 85cm offset, Kuhne LNB transponder noise 10-12dB above noise floor

    TX 90cm grid-dish ("WLAN -dish") vertical polarisation with 15W on antenna; signal strenth in the lower 1/2 of "average" (but TX-antenna not yet 100% alligned).


    Tnx for the good job to all who are spending their time and work for this project !


    73 de Johannes

  • Hello,

    Yesterday I did my first uplink attempts on Es'hail-2. On Rx side I use an old 2.6 m prime focus sat-tv dish with PLL-locked LNB (NJR2637E) and USRP N210. Transponder noise floor is up to 20 dB above background noise. Both Rx and Tx LOs are phase locked to a common 10 MHz rubidium clock. On TX I tried first my 4.5 m dish with a CP septum feed designed for 13 cm EME work and about 10 W otput from PA into 15 m (not so low loss) cable. This gave by far too much EIRP for the satellite. As a quick fix I used a 6 dB attenuator at PA output, but it was still a bit too high. Later I just tried with 10 W power into septum feed without dish and got still audible CW signal. I will most likely make a more permanent setup with a small dish in near future.

    73, Viljo ES5PC