Posts by IZ4RYB

    Hi,


    I've received an email from admin@amsat-dl.org advising me oe9dgv sent me the following message;


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    Hi Marco!


    Tnx for interesting article abt the SKY66292-11 13cm Amplifier - very good!


    I´m prepareing a holiday equipment fror QO-100 with adalm Pluto sdr. If I understand you right this Amp. with a LZ5DP Amp works well for narrowband tranponder.


    Can you please explain me, what is to do, that the SKY66292-11 works with pluto and LZ5DP Amp? Do you have a ptt line from pluto?


    73, oe9dgv, Guntram.

    -------------------------------------------------------------------------------------------------------------


    I'll expected to see the message in this tread but I do not see it.


    Bye the way I'm answering to oe9dgv here under.


    About the SKY66292-11 you need just to apply the vcc and bias pins to 5v, about 600ma to have 4w output.


    Then you need to apply 2v for the PA enable using 3 diode and one switch. You have first to apply 5volts, than 2v and
    than apply rf input from pluto.


    Pluto is directly connected to the module witch is directly connected to the SG LAB 20w PA.


    I'm using it with DATV so I do not need any PTT, if you want to modify your pluto to add ptt just follow the


    https://wetzsteinfunker.de/wor…ang-fuer-den-adalm-pluto/


    Bye !


    DE IZ4RYB

    Hi,


    doing some driver chain calculations I've discovered I've been wrong with the skywork gain, it is not
    45db but 35db as written in the tread title.


    So the calculation is the following, pluto exit with -10dbm at 2409Mhz and 2Msymbol, +35db skyworks,

    +16db sglab, +15db Ampleon 500w we will get theoretically 56dbm or 398w. Fore sure I'll not

    exceed the 200w due to linearity and datv tv signal shape shoulders.


    Sorry for the gain mistake but I've been so excited by the skyworks driver, I've increased the module gain
    by 10db.


    Bye!


    DE IZ4RYB

    Hi,


    I wold like really to give a lot of congratulations for Fausto IK4NMF, he gave me all the great hints to built up this
    2,4ghz QO100 up station. With his Agilent Vector and Bolometer analyzer and great microwave experience.


    Many thanks to F5OEO for the great Pluto firmware.


    Many thanks to Alessio IK4IDY wo gave me all the suggestions to configure pluto with F5OEO and OBS studio.


    Bye!


    The IZ4RYB!

    Hi,


    yesterday I did some measurement with really good results, the Sky-power driver works

    perfectly, also because I've used Sky-power EMI certified module.

    Hereunder attached pictures description;


    q1-cw-5dbm_in-36dbm_out.jpg ->2,4ghz CW 5dbm-in 36dbm-out 4w as declared by Sky-Power

    probably using db4um Pa pcb we have only 2w only due to home made mounting method.


    q2-dattv-1ms_pluto-8db.jpg -> Shoulders -40db using Pluto F5OEO firmware -8 att and Sky-power module.


    q3-dattv-1ms-300mw_out-36db_pluto-6db.jpg -> Shoulders -36db using Pluto F5OEO firmware -8 att and Sky-power module,

    output power 300mw.


    q4-driver-skypower-dut.jpg -> small pcb to hold the Sky-power module, one power on switch, another enable switch applying
    1.9v to the module, 1.9V are got with 3 series 1n4148 and one 2,2k resistor connected to 5v.


    q5-driver-skypower-dut-inplace.jpg -> Module in place. Now the chain is Obs studio, pluto with F5OEO firmware, sky-works driver,

    sg lab 20w amplifier, 500w Ampleon dual LDMOs PA. I like to underline the module has not any shielding case and even it
    is 10cm far from the 500w pa it works perfectly stable, that is due to the right device used in the right frequency an the
    same is for 500PA. I currently do not have any UMTS adapted devices. That is the main chain stabilities reason, all right
    frequency device with completed adapted pcb.


    q6-driver-skypower-heat-sync.jpg -> the sky-power comes with heat sync really cold with 1w out power.


    r1-2.4ghz-5cell-filter.jpg and r2-2.4ghz-5cell-filter-shape.jpg -> I had wifi problem with the previous driver chain so I've
    tuned a filter to reduce 500w PA wifi interference. I've not used it because the entire chain from pluto to 500w ampleon

    pa it is very clean.


    Thats all!


    i'm really happy about this driwer, it cost 120euros but completly justified bye the results.


    DE IZ4RYB


    Bye!

    Hi Michael,


    other recurring old man behaviour I hate is the strong efforts done

    to save money, instead of looking to price/results degree.

    I use to define my objectives first and than looking to the price as last,

    if it is too much for me wait until I've saved enough money.


    Life it is not only a metter of price.


    By the way you are right everyone has his own price objectives and time
    schedule.


    About modifying the pcb it is not a problem for me because I'm working for
    a Japanese software company producing PCB design software.


    Thank you for your suggestion.


    Bye!


    DE IZ4RYB.

    Dear DD9FJ,


    many thanks for suggesting me where to buy a pcb.


    Unfortunately I'm looking to a ready to use driver, not looking at all to

    build by myself something already available in the market at the right
    price.


    If a module already exists on the marked I'm not looking to invent
    warm water.


    The time are changing, we are old man but not for that we have to build
    everything.


    I've ordered the module from US, it arrived in a couple of days, mounted
    tested with the heat sink already.


    I did the same with ampleon 250w pallet.


    I've build up the ampleon 500w because was not on the market.


    That is what I'm looking for.


    Do not misunderstood me I'm talking about module not about systems,

    like entire up/down QO100 station.


    Mounting by myself a small pcb is is not a challenge anymore for me.


    Sorry for that!


    De IZ4RYB!


    P.s. I'm sorry I've spent many words than you but that is the way to be polite I know.

    Hi,


    I've found an interesting driver to be used with Pluto.

    Currently I've a too long driver chain from pluto to Ampleon 500w PA.

    Such as ;

    Pluto at 1,3Ghz->3Mhz-3Ghz amply->BU500->wifi 2w->Sg Lab 20w->500w Ampleon PA.

    Even the chain is very long I do not have stabilities problems but I would like
    to improve Dattv shoulders.

    I'll substitute BU500 and Wifi 2wat amplifier with the SKY66292-11 to use
    pluto directly at 2,4ghz and avoiding upconverter.


    See attached pictures.


    Bye!

    Hi,


    happy new year to everybody!


    I'm currently just testing the dongle.


    The receiving frequency is 1301,250 MHZ because I've another pc with Pluto and F5OEO transmitting using OBS on that frequency.


    I've the pluto with original tx antenna and the dongle with a small antenna, so I'm doing local tests before going to satellite.


    I've also the minitioune with another small antenna receiving perfectly what I'm transmitting with Pluto ad 1301,250GHZ.


    I've tried to move the frequency cursor from 144MHz to 1400 Mhz, but the waterfall always grey, so I think the
    dongle does not receive any signal.


    Using the dongle with SDR angel I can receive any kind of FM SSB CW, so the hardware seem good.


    Many thanks in advance for your help!


    DE Iz4ryb!

    Hi,


    many thanks for your answer. I do not think we have the same dongle. If you look to the first attached image my dongle
    is not exactly as yours. By the way to give some other details, the dongle works perfectly with SDR Console so I think the
    windows driver it is correctly installed and the dongle it is not broken.

    When I run dvb-s_console I can open the device but the waterfall it is grey as in the attached pictures.


    Bye!


    DE IZ4RYB

    Hi,


    I'm just trying to use an 820T2 Usb dongle SDR.


    Running dvb-s_gui it opens the dongle but I'm not receiving anything, has someone used this dongle?


    Many thanks in advance.


    Bye!

    Hi,


    first 500w Ampleon Pa tests, first changed PA to 105cm cable to 1/2inches Cellflex to stand up to 700w at 2,4Ghz as in attacched 105cm-ofset.jpg.

    First dattv tx trial at 1Msymbol immediately stopped due to over power.

    Second tests 2Msymbol see pictures 2Msymb.jpg.

    Last but not least new upstation see Upstation.jpg.


    Power around 130w shoulders 50db.


    Bye!

    Hi,


    this kind of thermal bias NTC compensation is suitable only for CW operation with a bias current around 20ma, using water cooling.

    When the LDMOS is used around its maximum power the NTC reduce the bias current and the output power decreases leaving the
    LDMOS temperature under 60 degrees. We are using the LDMOS at half of the maximum power with around 800ma bias current.

    If we leave any kind of NTC thermal compensation we are not getting any power decrease with bias we will only reduce the bias
    current and the linearity creating DVBS distortions.

    The best DVBS thermal compensation suitable for DVBS operation, should be a microprocessor measuring with internal ADC the NTC
    resistance and regulating the input power with a digital step attenuator.

    We are not a SAT broadcasting TV so we do not need to have continuous operation, so I've just placed one ohmmeter connected to
    the internal pallet NTC sensor and I just check the resistance stays around 400 ohm during Tx.


    Bye!