Satalite Help Please

Discussion in 'Satellite and Space Communications' started by KF7CCY, Dec 17, 2009.

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  1. KF7CCY

    KF7CCY Ham Member QRZ Page

    I am tring to use my Yeasu vx-8 to communicate with amature satalite's. I am using a program called Orbitron to track them. As of now I have not been able to reach one or recive any transmisions from one. I do have a 2 meter whip on my roof and I was told that should work for at least the AO-51 satalite. What am I doing wrong.
    Thanks Newbee KF7CCY
     
  2. WJ5O

    WJ5O Ham Member QRZ Page

    Last edited: Dec 17, 2009
  3. K9CHP

    K9CHP XML Subscriber QRZ Page

    First rule for satellites (but good elsewhere too) if you can't hear'em, don't call'em. Since you cannot hear what is going on, your call will just QRM those who can hear...

    So let's work on hearing the satellite. I hope you set up Orbitron correctly as for your QTH (home location). Now your antenna will not work well for passes that are high, which are the best passes. Simply a vertical, even high gain collateral will not help much other than on passes that are close to the horizon. Don't despair though as many have made contact with AO-51 and other satellites just with an HT!

    The stock antenna that came with the VX-8, well, it is not great. You may want to check out Smiley Antennas http://www.smileyantenna.com/product_info.php?cPath=21_27&products_id=55 Get the SMA connector for the VX-8.

    Now with this antenna, go out, yes, I know it is cold in OR, but you're used to it :eek: and with a simple compass, look at the expected trajectory of the satellite. Get to a place where you have line of sight to that trajectory, no houses, no trees in the way, as much as possible. Now at the right time, aim your antenna towards the ground and raise it only as needed, work it by sound, like if you were dousing for water. Do NOT try to transmit. Just work at receiving the satellite for a few passes. Working it over the hood of a vehicle or the bed of a truck might help as it gives you a reflector of sorts.

    Listen to the short style QSO. Know your Maidenhead locator. Eventually, you will want to reply to a call or throw your callsign in, then, if you feel ready, try it.

    You will also need to make adjustments for Doppler effect, especially on the receive side but I think that for now, this might help you enough.

    Living in upstate NY, I'm not working satellites in the dead of winter, but I did in the past...

    Amir K9CHP
     
  4. KF7CCY

    KF7CCY Ham Member QRZ Page

    Satalite Help

    Thanks for the tips. I'll give it a try again now that I know how to start. I think I have Orbitron setup correctly I used the GPS info from my VX-8 to set it up.
     
  5. WA9SVD

    WA9SVD Ham Member QRZ Page

    I'd also suggest going to:

    www.heavens-above.com

    to at least verify you have Orbitron set up correctly. ( I assume you have downloaded the latest TLE's [Two-Line Elements] from Celestrak and have incorporated them into Orbitron...)

    Then check:
    http://www.k6lcs.com/

    Clint Bradford's web page. He tells how to work the FM birds with an H-T.
    HINT: you will need at LEAST an aftermarket whip antenna for both receive and transmit to work satellites. I've worked AO-27 and AO-51 several times each with only two H-T's (one 2 Meter H-T and a 440/1.2GHz dual band) with Diamond dual (or tri) band whips. One AO-27 contact was with only 1.5 Watts on 2 Meters, so you should have reasonable success. Also check out the AMSAT (www.amsat.org) web site for other help and information.

    Good luck.
     
  6. W9GB

    W9GB Ham Member QRZ Page

    A majority of the current operational amateur radio satellites are LEO (Low Earth Orbit) and relatively low power, which means they are only 250 to 450 miles above the earth's surface and you will only have an operational window maximum of 8 minutes, depending on the satellite's pass from your QTH.

    You have several suggestions for web based orbital prediction programs --
    these are only as accurate as the sponsor (and their updates from NORAD/NASA published element sets)
    http://www.satobs.org/satpred.html

    Orbitessera by Ken Ernandes, N2WWD is a good reference web site
    http://www.mindspring.com/~n2wwd/

    Celestrak by TS Kelso is another good web site
    http://celestrak.com/

    You may wish to consider an Arrow-style antenna (build or buy)
    for best signal reception and transmission to your desired satellite.
    http://www.arrowantennas.com/
    On the web site there is a video by Randy, K7AGE (No. California)
    that you can watch for actual setup and operation.
    http://www.arrowantennas.com/146-437.html

    AE6LX shows how to communicate through satellites using his Yaesu HT
    http://vimeo.com/6868846

    w9gb
     
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