AO-7 Mode A Reception

Discussion in 'Satellite and Space Communications' started by KS1G, Sep 18, 2021.

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  1. K8XG

    K8XG XML Subscriber QRZ Page

    I worked RS-13 and I think it was RS-15 on an Antron 99 10 meter antenna with a Uniden 2510 10 meter rig and a Kenwood 2meter all mode mobile on a discone.. did that for about 2 years and have some old QSL cards from that exercise
     
  2. N4UFO

    N4UFO Ham Member QRZ Page

    RS-12/13 was great! I had like a 150 grids and 47 states as well as a number of DXCC including into Europe. Used everything from a Hustler vertical to a dipole to a beam to hear it. I even hosted a 'how to' webpage and a forum to help people get on that bird. <sigh!> Ah, the good ol' simple days. We are supposed to be getting a new Mode K bird soon, but I can't remember the details. Sure would be nice if it were active during the next sunspot peak and work some more 'over the horizon' DXCC with it! :):cool:

    If you have a moment to look, see if you have an AC5DK card in your stack. RS-12/13 was on mode KA quite a bit if I remember correctly.
     
    K8XG likes this.
  3. ZL3OF

    ZL3OF Ham Member QRZ Page

    In the early 1980's I recall that I used to work mode A using a 10 metre horizontal quad loop antenna. It was just a loop of wire strung between a couple of convenient trees and the fence and about 1.7 metres above the ground. It was connected directly to the coax, no transformer and no balun. The 2 metre side was a 5 element yagi fixed at about 25 degrees with "armstrong rotator" pipe mounted on the bench and straight up through the roof, just reach over and give it a twist. It worked remarkably well.
     
  4. K2WH

    K2WH Premium Subscriber QRZ Page

    How does one know when the sat is in A or B ?

    What is its schedule ?
     
  5. K7WDO

    K7WDO Ham Member QRZ Page

    You can check the AMSAT status page at https://www.amsat.org/status/ to see what AO-7 is up to.

    Right now, AO-7 is staying in constant illumination (full sunlight, no eclipses) and there's a 24-hour timer that cycles it between Mode A and Mode B. Going by the last few passes I've caught, it seems to switch modes at around 00:46z. Looks like it was Mode A today (29 Sept. 2021) but it'll be switching back to Mode B by 01:00z. This pattern should hold until AO-7 starts going into eclipse again. When that happens, it tends to power up in Mode B so we won't see any Mode A again until the next period of full-time sunlight and it says on long enough for the 24-hour to trigger a mode change.
     
  6. KS1G

    KS1G Ham Member QRZ Page

    Progress report: 10/1/21 2037z pass (~74deg max). Got the 10M "Buddideltaloop" set up a few minutes into the pass, oriented so main beam was (hopefully) aligned NNW-SSE. Further luck, the neighborhood noise level was only S4-5. Was able to copy my CW a few times down at the 5W level, more typical needed 20w. Yes, my station does not hear well. Called CQ a few times, K9CIS came back just after my TCA and we were able to have a QSO in spite of the weakening signals and QSB as the satellite moved towards my LOS. So 1st AO-7 Mode A QSO in the log! Other improvements - new RG8x from feed point to base of mast, then ARR 10M preamp and LMR400 back to the radio (IC9100).

    Next steps: See what I can do to get better gain than the delta loop, or try a vertical for one pass to see if non-directivity is any help (not optimistic). Ideally, get something lightweight but w gain (moxon or 2 el yagi) mounted above my az-el so I can stay pointed at the bird. Or operate back/front yard portable with Arrow for the uplink and armstrong rotator for the downlink. [All this for a few minutes alternate days for a few months -ah the things we hams will go thru to try something "new"!]
     
    K7WDO, N4UFO, WE4B and 1 other person like this.
  7. KD9NGV

    KD9NGV Ham Member QRZ Page

    I decided to try Mode A this fall also. I originally had a 10 meter inverted V for the downlink and an FT-817 going up. After hearing KE9AJ a few times I contacted him
    by E-mail ( He's only about 100 miles north). He is a guru regarding Mode A! He suggested a delta loop for 10 meters and more power on the uplink. The delta loop has
    been a great antenna. I homebrewed one with some insulated 16 ga. I added a Mirage B-34-G amp to the uplink (about 25 watts) and things started coming together. I've managed
    5 contacts (3 CW and 2 SSB) Mode A was my biggest challenge with the sats. I set up probably 20 times for those 5 contacts but it's a thrill when you hit!
     

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