[amsat-bb] FO-29 QSO Below the Horizon

John Papay john at papays.com
Mon Mar 26 07:45:49 PDT 2012

Every now and then someone asks about the possibility
of making a satellite QSO when the bird is below the
horizon.  Once in while it happens as it did with Adrian,
AA5UK/KH6, on FO-29 this morning at 0849utc.

Adrian has been operating from KH6 and trying to give out
WAS to the deserving.  Many have made their first Hawaii
QSO thanks to his efforts.  I had a 0.8 degree pass this
morning on FO-29 but when Adrian was at 3 degrees, I was
at 0.0 degrees.  There was a short window of opportunity
after that point.

As I was waiting for FO-29 to come up over the horizon I started
hearing Adrian at -0.9 degrees.  At -0.5 I called him and we had
a qso that ended about 2 seconds after my AOS.  My recorder is
configured to start recording at AOS and it only captured a few
seconds of my last transmission.  Doug KD8CAO had his recorder
running so you can hear my qso that took place below the horizon.
I have my ground elevation in the setup so the calculations should be

The best opportunity for a below the horizon contact occurs when
the satellite is skimming the horizon rather than going away from
you.  If it is skimming there is much more time at the critical
-1.5 to 0.0 degree elevation and that is what happened this morning.
Recordings are on my website.  http://www.papays.com/sat/general.html

A big thank you to Adrian for making the effort to work the difficult
passes and stretch the limits.  If it were easy, everyone would be
doing it.

John K8YSE

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