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  • [Hackaday] A Satellite Upconverter Need Not Be Impossible To Make

    From Hackaday via rec.radio.amateur.mode@21:1/5 to All on Sun Aug 1 18:11:10 2021
    XPost: rec.radio.amateur.moderated

    amateur radio - Hackaday

    ///////////////////////////////////////////
    A Satellite Upconverter Need Not Be Impossible To Make

    Posted: 31 Jul 2021 07:00 PM PDT https://hackaday.com/2021/07/31/a-satellite-upconverter-need-not-be-impossible-to-make/


    Those readers whose interests dont lie in the world of amateur radio might
    have missed one of its firsts, for the last year or two amateurs have had
    their own geostationary satellite transponder. Called Es’hail-2 / AMSAT
    Phase 4-A / Qatar-OSCAR 100, it lies in the geostationary orbit at 25.9°
    East and has a transponder with a 2.4 GHz uplink and a 10.489 GHz downlink. Receiving the downlink is possible with an LNB designed for satellite TV,
    but for many hams the uplink presents a problem. Along comes [PY1SAN] from Brazil with a practical and surprisingly simple solution using a mixture of
    odd the shelf modules and a few hand-soldered parts.

    An upconverter follows a simple enough principle, the radio signal is
    created at a lower frequency (in this case by a 435 MHz transmitter) and
    mixed with a signal from a local oscillator. A filter then picks out the
    mixer product the sum of the two and amplifies it for transmission.
    [PY1SAN]s upconverter takes the output from the transmitter and feeds it through an attenuator to a MiniCircuits mixer module which takes its local oscillator via an amplifier from a signal generator module. The mixer
    output goes through a PCB stripline filter through another amplifier module
    to a power amplifier brick, and thence via a co-ax feeder to a dish-mounted helical antenna.

    The whole thing is a series of modules joined by short SMA cables, and
    could probably be largely sourced from a single AliExpress order without
    too much in the way of expenditure. Its by no means easy to get on air via Eshail-2, but at least now it need not be impossibly expensive. Even the antenna can be made without breaking the bank.

    We covered Eshail-2 when it first appeared. May it long provide radio
    amateurs with the chance to operate worldwide with homebrew microwave equipment!

    --- SoupGate-Win32 v1.05
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