[amsat-bb] AO-73 - Evening transponder time increasing in NorthernHemisphere

Mvivona Mvivona at yahoo.com
Wed Aug 19 03:03:25 UTC 2015

OK, this is a good one. 
I finally found why every time I tried AO-73 I kept hearing myself coming back on the downlink real squeaky and hard to understand. No matter how I tuned. It sounded like I was splattering all over the place. Here comes the funny part.
I am using a pair of earbud headphones to hear my downlink. However, I took them off for a second to reach for something. I forgot to put them back on and once again keyed up called CQ.  HOLY CRAP.. I got was getting into my souround-sound system real loud and squeaky. It actually startled me. All this time I thought I was hearing myself sounding real squeaky on the downlink in my earphones and it was actually my darned stereo system in the house.
I finally made my first linear contact. Woohoo.

Michael Vivona
Sent from my iPad

On Aug 18, 2015, at 10:26 PM, Paul Stoetzer <n8hm at arrl.net> wrote:


Nice to hear you work PV8DX right after my AOS on the 0215Z pass for
your first AO-73 QSO. I tried to find you afterward, but never heard
you again.

I worked AB4AN on that pass, heard a CW station that I didn't stick
around long enough to identify, and also heard N5KDB, though the sat
went over my building before I could work him.

Nice to hear some activity on the evening pass!


Paul, N8HM

> On Tue, Aug 18, 2015 at 9:20 AM, Mvivona <Mvivona at yahoo.com> wrote:
> Clayton,
> Recently you may have heard me attempting to find myself on the bandpass. I
> am tuning manually, but can never get a clean downlink of my voice. Also, I
> only show up on my spectrum as a small spike and others show up nice and
> strong.
> I have tried several times to work it with not much luck. I am using an
> IC910H, dual Arrow antennas on rotor, no preamp yet, but my coax is quite
> short with about 3db loss on the 70cm and almost nothing on the 2m. On a
> high pass I can hear myself, but I can never get my audio to sound right. It
> always sounds like I'm not on frequency as my voice is always real high
> pitched through the tuning range. I'm hitting the bird with about 200W ERP.
> I thought I might be getting into my frontend with harmonics due to my
> antennas being only about 3 ft apart so I also tried using an eggbeater for
> the uplink and setting it 20ft away. Granted that dropped my ERP to about
> 100W, but still the same outcome, but with 100W I could barely hear my
> downlink. I can hear others nice and strong and they are clean sounding. I
> also tried a different radio just for the heck of it, but the same outcome.
> I use dual fed coax and switch polarity as the bird rotates.
> My settings are:
> Uplink - 435.130 - 435.150 LSB
> Downlink - 145.950 - 145.970 USB
> Michael Vivona
> Sent from my iPad
> On Aug 18, 2015, at 8:14 AM, Clayton W5PFG <w5pfg at amsat.org> wrote:
> One thing I might add: often I encounter stations spending a lot of time
> trying to find themselves on the transponder.  I suspect they are trying to
> calibrate their SatPC32/MacDoppler/gpredict.  Sadly, they spend so much time
> doing so that they miss out on the precious transponder time.
> Ditting/hola/test-test-test without sending a callsign doesn't even make for
> a good SWL report.
> I would suggest stations NOT try using computer control and enjoy the
> transponder with manual control.
> Chances are if you are not hearing your own downlink on AO-73, you probably
> either have a poor antenna/feedline OR (more likely) you are not listening
> in the correct corresponding downlink frequency for your uplink frequency
> into the transponder. AO-73 is VERY easy to hear!
> 73
> Clayton
> On 8/17/2015 21:13, Paul Stoetzer wrote:
> Good evening,
> As we're nearly two months pass the Summer Solstice here in the
> Northern Hemisphere, transponder time is increasing on evening passes
> over North America. Here in Washington, DC, on the 0155Z pass, I had 6
> minutes and 10 seconds of pass time from AOS until the satellite
> entered sunlight and the transponder switched off. I heard and worked
> PV8DX at my AOS, but no other stations were heard.
> AO-73 is currently the only amateur satellite consistently available
> during regular evening hours, even if not for an entire pass, so let's
> hear some more activity! It's really quite an easy satellite to work
> with the strong downlink.
> 73,
> Paul, N8HM
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