[amsat-bb] Re: SO50 problems and questions

Andrew Koenig ke5gdb at gmail.com
Tue Jun 9 21:32:32 PDT 2009

I also forgot to mention that a PreAmp makes all of the difference. I worked
a few passes with N5AFV this past weekend for Museum Ship weekend, and he
let me borrow his preamp. On AO-27, it went from an S-1 to an S6, and with
SO-50 it went from an S-0 (still audible though) to an S-4. I'll also
embarrassingly admit that I had my arrow pointed in the wrong direction (for
part of the pass), and AO-27 was still audible with an S3, but only with the

I believe we used an AAR SP450VDA.

On Tue, Jun 9, 2009 at 11:22 PM, Andrew Koenig <ke5gdb at gmail.com> wrote:

> 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
> schedule).
> 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
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> --
> Andrew Koenig

Andrew Koenig

More information about the AMSAT-BB mailing list