[amsat-bb] Re: SO50 problems and questions

Andrew Koenig ke5gdb at gmail.com
Tue Jun 9 21:22:01 PDT 2009

I would try taking the antenna off of the tripod for a little while. The
polarization of the satellites changes constantly, and with the antenna on
the tripod, it's difficult to compensate for those changes.

Also, AO-51 is a much stronger bird than SO-50, but AO-27 is the strongest
at the moment. AO-27 has the same frequencies as SO-50, but there is no
tone, and it's got a timer on it that turns it on when it reaches (about)
the Gulf Coast line (for the purposes of maintaining battery power). You'll
have time to get your antenna in the right place with the 20 seconds of
telemetry it starts with (see http://www.ao27.org/AO27/index.shtml for a

For your situation, I would recommend trying AO-27 until you are familiar
with the satellites. AO-27 isn't as crowded as AO-51, but it's also not as
quiet (both in traffic and output) as SO-50.

Don't quote me on it, but I think AO-51 has less than 500mW output right
now, AO-27 is 500mW and SO-50 is 250mW.

Good luck! Once you get the hang of it, it's easy enoguh that a teenager can
do it (I'd know..)

73 de KE5GDB

On Tue, Jun 9, 2009 at 9:18 PM, LeRoy Miller
<kd8bxp at sprint.blackberry.net>wrote:

> Hello
> I am relatively new (- I have been tring on my own to get the hang of
> working the satellites) with little or no luck.
> I have been posting my failed results to twitter and getting over
> frustrated in my attempts - luckly there have been a few who have given me
> pointers. And one very nice person kl7cn let me call him and he talked me
> though a few things during the call he said maybe I should try the SO50. So
> today I did try it
> And much to my surprise and happiness it was easy enough to pickup and find
> and things seemed to working for me (He told me that is was a quite machine
> and that I might have to look for it a bit)
> The pass I tried was at 1710 UTC (110 pm local est) and the sat was moving
> from the southwest to the northeast from my previous trys on the AO51 I knew
> that I would probably not get it while it was still low (less then about 20
> degrees - also because of where I was pointing the antenna that low I was
> pointing right at a building) I reasoned that if I started looking at about
> 24 degrees I would being doing much better (so that is what I did) at about
> 1714 or 1715 UTC I had heard the SO51 for the first time, still a bit rough
> and probably still a little low by the time it was up around the 40 degree
> mark I thought
> What the heck I am here, people are talking why not try to make a contact -
> so that is what I did
> I think I waited just a little longer got a nice strong signal and put my
> call out
> KD8BXP em79 --
> What I heard on the downlink really surprised me - it was this horrable
> noise (it almost sounded like when 2 people double) I don't know what I did
> but thought ok maybe feedback from the microphone so I unpluged the external
> and tried again
> I got the same horrable sound
> Now I am sorry up front for this noise I am sure people heard it - so if
> you were on around 1717 - 1720 I am so sorry upfront
> But that leads me to my question - what did I do wrong?
> And how can I correct the problem and try again
> I have been really frustrated with the AO51 so much so that I almost put my
> rig antenna and what not on ebay 3 days ago - I cooled off but I really want
> to work this bird
> It seemed (at least to a newbie) an easy one to find and maybe make
> contacts on.
> You will need to know the setup:
> TH-D7 A (not the G model I have a G but didn't use it this time)
> Arrow (2 meter/440) mounted to a telescope tripod
> Eeepc running ubuntu linux a gpredict
> External mic for the radio
> I was on 145.850 pl 67hz for the uplink
> And 436.800 for the downlink
> Radio was in duplex mode and sql was turned off (or open if you prefer)
> And the balance on the speaker was set for only the 440 side
> I was at 40 - 50 degrees when I first keyed up and the second time would
> have been when it was at its highest point of between 64 and 74 degrees
> I was on the high power setting
> I have used this radio for both local repeater work and aprs and no one has
> ever told me that it was making horrable noises
> And I think if it was making horrable noises while transmitting aprs the
> data would be corrpted
> I hope I have given enough information. I hope someone can help I don't
> want to make horrable noises again
> One other thing but I am sure it is my problem not one that someone fix so
> to speak
> Once the satellite reached its max and started back down - I lost it
> completely couldn't find it again
> I think it was me one leg on the tripod is bent and started to collaspe
> while I was turning the antenna to start it pointing in a north east direct
> Thanks for the help in advance I write a lot to ask something simple sorry
> about that
> LeRoy, KD8BXP
> Sent on the Now Network™ from my Sprint® BlackBerry
> _______________________________________________
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Andrew Koenig

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