Posts by DB2OS

    what about asking our friends from ISISspace? I think they had plenty of customers on board..

    Done - not sure if they might report back officially due to NDA ;-)

    But normally every launch provider has to ensure that licenses are legally issued to give launch authorization and ITU is informed about used frequencies. Perhaps someone will find out what's (if et all) in the database..

    Excellent analysis from Daniel Estévez, EA4GPZ, who just wrote on Twitter:


    "I confirm that the unidentified satellite from #VV16 which is transmitting on 437.515 MHz (probably illegally) uses 1k2 FSK with a @GomSpaceGroup AX100 transceiver in ASM+Golay mode.


    This is from a packet received earlier by Mike DK3WN. Nothing seems useful to ID the satellite."


    And there seems to be another unknown satellite infringing ITU rules for the "amateur satellite service"...


    Nico PA0DLO made Doppler measurements, which show that the unidentified satellite is object 46273 (2020-061B). Frequency: 437.515 MHz.


    In this case SatNOGS will be very helpful to us to identify and document those illegal transmissions in the amateur satellite service:

    https://network.satnogs.org/ob…ver=&station=&start=&end=


    PE0SAT and JA0CAW have already analyzed the recordings using the 1KUNS-PF decoder from Mike DK3WN, but no identifier was found. But could be another format... Several people are currently working on it..

    ZRO test...

    During AMSAT-OSCAR-13 times, AMSAT offered the so-called "ZRO Memorial Technical Achievement Award Program" or just "ZRO Test". This activity was a test of operating skill and equipment performance.


    During a typical ZRO run, a control station will send numeric code groups using CW at 10 words-per-minute. At the beginning of the run, uplink power from the control station is set to match the general beacon downlink strength. This is level "zero". The control operator will send and repeat a random five-digit number, then lower his uplink power by 3 dB (half power) and repeat the procedure with a new random number (level "1"). This will continue to a level 30 dB below the beacon (level "A").


    A participating listener monitors the downlink signals till he can no longer copy the numbers. Those who can hear the beacon will qualify for the basic award by copying the code group heard at level "zero". The challenge is to improve home-station performance to a point where the lower-level downlink signals can be copied (levels 6 through A). To date, only one station (Darrel Emerson AA7FV) has successfully copied level "A".


    https://www.cv.nrao.edu/~demerson/cs/zrodata.htm


    The Weak-Signal Capability of the Human Ear


    I'm not sure if such an ZRO test still makes sense as described above, but at least lowering the CW Beacon in 3dB Steps starting at Beacon level could be very useful for users to check the performance of their receiving systems as suggested by several users above.


    We discussed this general idea in our AMSAT-DL QO-100 Team meeting today, but we still need to agree on some requirements/specification before implementation on the CW Beacon could even start...


    Suggestions, Input is welcome...



    73s Peter

    First Element of ARISS Next Generation (Next-Gen) Radio System Installed in ISS Columbus Module


    September 2, 2020—The ARISS team is pleased to announce that set up and installation of the first element of our next generation radio system was completed and amateur radio operations with it are now underway. This first element, dubbed the InterOperable Radio System (IORS), was installed in the International Space Station Columbus module. The IORS replaces the Ericsson radio system and packet module that were originally certified for spaceflight on July 26, 2000.


    Initial operation of the new radio system is in FM cross band repeater mode using an uplink frequency of 145.99 MHz with an access tone of 67 Hz and a downlink frequency of 437.800 MHz. System activation was first observed at 01:02 UTC on September 2. Special operations will continue to be announced.


    The IORS was launched from Kennedy Space Center on March 6, 2020 on board the SpaceX CRS-20 resupply mission. It consists of a special, space-modified JVC Kenwood D710GA transceiver, an ARISS developed multi-voltage power supply and interconnecting cables. The design, development, fabrication, testing, and launch of the first IORS was an incredible five-year engineering achievement accomplished by the ARISS hardware volunteer team. It will enable new, exciting capabilities for ham radio operators, students, and the general public. Capabilities include a higher power radio, voice repeater, digital packet radio (APRS) capabilities and a Kenwood VC-H1 slow scan television (SSTV) system.


    A second IORS undergoes flight certification and will be launched later for installation in the Russian Service module. This second system enables dual, simultaneous operations, (e.g. voice repeater and APRS packet), providing diverse opportunities for radio amateurs. It also provides on-orbit redundancy to ensure continuous operations in the event of an IORS component failure.


    Next-gen development efforts continue. For the IORS, parts are being procured and a total of ten systems are being fabricated to support flight, additional flight spares, ground testing and astronaut training. Follow-on next generation radio system elements include an L-band repeater uplink capability, currently in development, and a flight Raspberry-Pi, dubbed “ARISS-Pi,” that is just beginning the design phase. The ARISS-Pi promises operations autonomy and enhanced SSTV operations.


    ARISS is run almost entirely by volunteers, and with the help of generous contributions from ARISS sponsors and individuals. Donations to the ARISS program for next generation hardware developments, operations, education, and administration are welcome -- please go to https://www.ariss.org/donate.html to contribute to these efforts.


    ARISS--Celebrating 20 years of continuous amateur radio operations on the ISS!


    Amateur Radio on the International Space Station (ARISS) is a cooperative venture of international amateur radio societies and the space agencies that support the International Space Station (ISS). In the United States, sponsors are the Radio Amateur Satellite Corporation (AMSAT), the American Radio Relay League (ARRL), the ISS National Lab-Space Station Explorers, and NASA’s Space Communications and Navigation program. The primary goal of ARISS is to promote exploration of science, technology, engineering, the arts, and mathematics topics by organizing scheduled contacts via amateur radio between crew members aboard the ISS and students. Before and during these radio contacts, students, educators, parents, and communities learn about space, space technologies, and amateur radio. For more information, see www.ariss.org.


    Media Contact:

    Dave Jordan, AA4KN

    ARISS PR

    Achim DH2VA has graphically illustrated the relationship between the various dependencies and how the SNR behaves with the size of the dish or which factors dominate.


    The graphics are also part of our official QO-100 presentation.

    https://amsat-dl.org/wp-conten…Hail2-AMSAT-DL-latest.pdf



    The blue curve shows that a small dish leads to considerable disadvantages, but the advantages above 1-1.5 meters are at some point only in the range below 1dB.

    Hi Chris,

    Yes I was wondering the same looking at it, the arrow is not exactly showing the exact location ;-)

    But I think from the zoomed picture is more clear.. Good luck!

    73 Peter

    DG8KD I think it's the wrong photo.. some photos seem to be correct...

    The description says:

    Specifications:

    It is HDMI video capture card, HDMI input resolution 3840×2160 30Hz, USB output resolution 1920×1080 30Hz. And it support 8/10/12bit deep color.

    As a matter of interest, why not uplink from Germany where it would be easier to access? Genuine question.


    Mike

    Hi Mike,


    technically we could, practically we see no urgent need at the moment and in particular after the last fix. We have installed a beautiful dual-redundant full setup at Es'hailSat in Qatar and we have have excellent professional support from the engineers there. We should keep using those resources. We had also additional plans, but due to the pandemic and other things we shifted those activities to next year..


    73 Peter

    here my received files:


    https://network.satnogs.org/ob…w1&results=d1&start=&end=


    unfortunately the SatNOGS SSTV decoder does not work well, but there is a trick:


    1) Install SOX on your Windows computer

    http://sox.sourceforge.net/


    2) Install MMSSTV

    https://hamsoft.ca/pages/mmsstv.php


    3) on the SatNOGS Observation go to Downloads and right-click on the Audio button to save the .OGG audio file


    4) Convert .ogg to .wav for MMSSTV

    in the directory (using CMD for example) you can use the following command line (or write a batch file) to convert the OGG-File to Mono and samplerate 11.025 kHz. Rename the files accordingly..


    "C:\Program Files (x86)\sox-14-4-2\sox.exe" in.ogg -c 1 -r 11025 out.wav


    5) Open MMSTV and load the above out.wav file in the play dialog box. You might first enter *.wav in the search box.


    6) Voila !! This way you can view the SSTV transmissions from around the world...


    rock solid with Anjo-Eggbeater:


    73s Peter

    ARISS News Release No. 20-10

    Dave Jordan, AA4KN

    ARISS PR

    aa4kn@amsat.org



    FOR IMMEDIATE RELEASE


    SSTV Event Scheduled for early August



    August 03, 2020 — A Slow Scan TV (SSTV) event is scheduled from the International Space Station (ISS) for early August. Date and times for the event are Aug 4 (12:25-18:10 UTC) for setup and operation and Aug 5 (08:15-18:25 UTC) for operation and close down. This is an MAI-75 experiment activity developed by the Moscow Aviation Institute.


    Images will be downlinked at 145.8 MHz and the expected SSTV mode of operation is PD 120. Radio enthusiasts participating in the event can post and view images on the ARISS SSTV Gallery at https://www.spaceflightsoftware.com/ARISS_SSTV/ .



    About ARISS:

    Amateur Radio on the International Space Station (ARISS) is a cooperative venture of international amateur radio societies and the space agencies that support the International Space Station (ISS). In the United States, sponsors are the Radio Amateur Satellite Corporation (AMSAT), the American Radio Relay League (ARRL), the ISS National Lab and NASA’s Space Communications and Navigation program. The primary goal of ARISS is to promote exploration of science, technology, engineering, the arts, and mathematics topics by organizing scheduled contacts via amateur radio between crew members aboard the ISS and students. Before and during these radio contacts, students, educators, parents, and communities learn about space, space technologies, and amateur radio. For more information, see www.ariss.org.


    Media Contact:

    Dave Jordan, AA4KN

    ARISS PR

    This morning the DATV-Team (Thomas&Stefan) successfully performed remote-update of the Firmware and the DATV Beacon is back to normal.


    As an additional countermeasure a SW watchdog will perform a reboot every 24 hours. During the reboot the DATV Beacon will stop for a short period.

    Today the DATV beacon stopped completely.


    After a hardware reset was performed the DATV beacon was back with nominal level, but with garbage TS.


    A second reset procedure also did not cure the problem.



    For tomorrow at 08:00 UTC we have planned a remote maintenance session for further analysis by our DATV-Team, including Firmware update.


    And please remember, the A71A DATV Beacon frequency is *exclusively* reserved for our groundstations and should not be used even if the Beacon is Off; Thank you!