[amsat-bb] Re: LEO's

Wed Jun 18 07:45:46 PDT 2008

Interesting link to P3E.  Obvioulsy written in early 2007 and talks 
about P3E launch in mid-2007.  This is the only link I have seen that 
offers muli-lingual translation.  All other P3E pages are in 
German.  Has anyone found any info more up to date?  I believe this 
is how this topic got its start...wanting P3E info!

Domenico states the situation, well, I think.  Any who actually 
experienced working AO-10/13/40 know that it does not take a 
complicated station.  It does take a SSB station and gain-type 
antennas vs. a dua-band HT with omni or Arrow antenna.  For other 
than mode-UV (what was called mode-B)(i.e. mode-VS, LS, and up) Leos 
are difficult to work due to high-rate Doppler change.  This is where 
computer-control of the radio is useful (maybe 
manditory).  Auto-tracking makes operating with gain-antennas on Leos 
less stressful.  But none of these were needed for operating 
AO-10/13/40.  I think those who added these features did so as a 
technical asset or for the enjoyment of the project.

My old AO-40 antenna system will be restored sometime this summer and 
I may get around to installing auto-tuning/tracking.  Then I may show 
up on AO-7 occasionally when the Moon is too low to work.

73 Ed - KL7UW

At 01:46 AM 6/18/2008, i8cvs wrote:
>Hi Art, KC6UQH
>
>You are correct 100% because the HEO AO40 was very easy to work
>using any old TX capable to run about 50 to 100 watt into 70 cm CW and SSB
>
>A 3 to 4 foot dish with a 2400/144 MHz downconverter in the focal point and
>connected to any old 144 MHz CW/SSB receiver mounted on the balcony was
>sufficient to receive a nice downlink from all over the world by many users
>at the same time for many hours every day.
>
>No complicated TX/RX radios and special software was necessary to compensate
>for doppler just made by hand.
>
>In my opinion from the operational point of view and communication
>efficiency the LEO FM satellites belong to the OCEA i.e. the "Office
>Complicating Easy Affair ".
>
>Unfortunately the young radio hams cannot understand what you writes because
>they were not fortunate enought to start their satellite experience with
>OSCAR-10 OSCAR-13 and the beautiful AO40 and this is why they are happy with
>the existing FM birds.
>
>Pulling for P3E...
>
>http://www.p3e-satellite.org/index.pl?step=pixelliste
>
>73" de
>
>i8CVS Domenico
>
>
>----- Original Message -----
>From: "kc6uqh" <kc6uqh at cox.net>
>To: "John Geiger" <aa5jg at lcisp.com>; <amsat-bb at AMSAT.Org>; <w0dxz at aol.com>
>Sent: Wednesday, June 18, 2008 7:36 AM
>Subject: [amsat-bb] Re: LEO's
>
>
> > >From my perspective HEO's are much easier to work. The doppler and the
> > antenna pointing go much slower. With a home brew antennas including a 10
> > turn helix on a 6' stepladder I worked stations from UK to Japan and all
> > parts in between on AO40. I used old radios and homebrew converters
> > including a modified LNB.
> >
> > A minmal setupI hung a 2M ht on a drop tap to read the signal strength of
> > the beacon. Adjusted the PrimeStar dish for strongest signal and eyeballed
> > the helix to be in line with the dish. I had many QSO's and one of the
> > better signals on the bird.
> >
> > You can't have a 20 minute QSO on a LEO.
> > Unless you have a computer controled station, you are spending most of
>your
> > time making adjustments. This leaves little time to learn and the best
>part
> > of it is the panic only lasts for 15 minutes.
> > The overhead part of the pass is crazy!
> > FM makes the doppler easy to handle, but any antenna with more than 6 dB
>of
> > gain becomes a pointing nightmere.
> > Art,
> > KC6UQH
> >
> > ----- Original Message -----
> > From: "John Geiger" <aa5jg at lcisp.com>
> > To: <amsat-bb at amsat.org>; <w0dxz at aol.com>
> > Sent: Tuesday, June 17, 2008 8:22 AM
> > Subject: [amsat-bb] Re: LEO's
> >
> >
> > > Hi Bob,
> > >
> > > I agree completely with what you say. Many people who don't think they
> > > have
> > > the equipment for the satellites really do-like a dualband FM rig and a
> > > small yagi.  I wouldn't be on the sats either if I hadn't started on the
> > > FM
> > > sats and found out how easy using them was.  Had a nice AO51 pass a few
> > > minutes ago also.
> > >
> > > 73s John AA5JG
> > >
> > > ----- Original Message -----
> > > From: <w0dxz at aol.com>
> > > To: <amsat-bb at AMSAT.Org>
> > > Sent: Tuesday, June 17, 2008 11:32 AM
> > > Subject: [amsat-bb] LEO's
> > >
> > >
> > >> RE:? Usefullness of LEO's...
> > >>
> > >> I think there should always be at least one accessable LEO-FM bird...
>for
> > > the very reason that some (WB6LLO) think there should not be. It gets
>you
> > > started with satellites.
> > >>
> > >> If I had not gone to a hamfest and seen Patrick demo use of the FM
>birds,
> > > I would not now be active on not only FM birds, but? the all mode birds
>as
> > > well. Without the FM birds, the? imtimidation factor would have been too
> > > much, I never would have gotten started.
> > >>
> > >> Every hobby needs an easy entry level possibility... for many it is the
> > > LEO's, FM.
> > >>
> > >> When I bought my first Harley, a Sportster,,, many said oh, a beginners
> > > Harley, yeah, maybe, but I would never have? bought a motorcycle? if I
>had
> > > to buy a full dresser as my first bike.? And yes, my first gun was a
>.410,
> > > not a 12 gauge.? And I learned to snorkel before I learned to SCUBA.
> > >>
> > >> FM LEO's have a purpose, a use. Not everyone can? chase the other
>birds.
> > > Live and let live. That is the fun part of the ham radio hobbyt, there
>is
> > > something for everyone.
> > >> There may be complaints about LEO-FM birds that are justifiable, but?
>the
> > > fact that you can work one with a HT is not one of those arguments.
> > >> Bob W0DXZ DM33
>
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