On 07/27/2014 09:57 AM, Jim Sanford wrote:
Tracking doppler on 2m and 70cm was hard enough at field day. I like
2GHz and up, but do not want to even think about the doppler.
At least not with analog modes.
High speed digital is very well suited to microwave in LEO as the link
budgets
On 07/22/2014 08:50 AM, Douglas Phelps wrote:
And, in a related question, wouldn't more proccessing demand more
power from the batteries/solar panels? I know my PC cetainly draws a
lot more power when the CPO is working hard.
Not really. The biggest load in a communications satellite, or
On 07/22/2014 11:05 AM, Robert Bruninga wrote:
The value of ham radio is providing communications where other systems
cannot. And of course, playing with toys just for fun.
I'd flip that around. With the Internet, mobile phones and other
ubiquitous communications, about the sole reason left
On 07/22/2014 11:19 AM, Bryce Salmi wrote:
All this requires much much much more power than a 1U satellite is
currently capable of producing. At least for always on type operating.
We'll get there eventually.
Only if you keep the analog modes since they hog nearly all the
available power and
On 07/22/2014 12:26 AM, Bryce Salmi wrote:
By usher in he was clearly referring to gaining technical abilities as a
group to attack more complex satellites.
That's not how I read it. In any event, AMSAT has already built far more
complex satellites; remember AO-40? (Maybe that one was *too*
On 07/22/2014 07:27 AM, JoAnne Maenpaa wrote:
When thinking of projects to enter into the digital communication
world plan on building or buying that digital interface to connect
your radio to the soundcard.
Soundcard interfaces to existing voice radios were a good start, but
it's time to
On 07/22/2014 07:49 AM, wa4...@comcast.net wrote:
SSB/CW birds are the only way to go and if you build it they will
come .
Think about what it would be like to tune for Doppler while working SSB
through a LEO satellite on microwave.
Before you say computer control, work out the effect of
On 07/22/2014 08:41 AM, Dave Marthouse wrote:
A digital satellite would imply loads of processing power on the
satellite. I would assume that with this additional activity that there
will be more
hardware on the bird with more complexity as this won't be a bent pipe
system.
Not
On 07/22/2014 06:49 AM, Clayton Coleman wrote:
Hi Phil,
The new era I speak of is AMSAT-NA's foray into CubeSats.
Well, I guess I could read that as when all you have is lemons, make
lemonade. AMSAT used to make spacecraft that, while small by
commercial/military/scientific standards, dwarfed
On 07/22/2014 04:06 PM, M5AKA wrote:
Phil, the technology you describe could equally well be used in
cross-band terrestrial transponders. Has anyone yet developed it for
terrestrial use ?
Sure, there are several digital schemes now appearing for ham VHF/UHF
voice use, such as D*Star
Since I think it so apropos to our discussion of old vs new technology
in AMSAT, I hereby quote in full today's Borowitz Report from the New
Yorker. Rarely does an item cause me to laugh and feel pain at the same
time, but this is one of those cases.
--Phil
[Picture of Buzz Aldrin saluting the
On 07/21/2014 06:00 AM, Gus wrote:
Probably because they didn't design a satellite. They designed an
entire system including ground station components as well as flight
hardware. The ground system components were made available such that
their target audience was able to upgrade their BUD
On 07/21/2014 02:00 PM, Gus wrote:
Actually, DirecTV is not available for purchase in my neck of the
woods. I can get a system installed, but it wouldn't be my system to
fiddle with.
Sorry about that, I was primarily thinking of AMSAT-NA members when I
said that. Forget the DirecTV receiver
On 07/21/2014 02:53 PM, Paul Stoetzer wrote:
I'm not totally unsympathetic to Phil's ideas. They have quite a bit
of merit, but clearly AMSAT would also have to develop the ground
station equipment in order for it to get a user base that would make
it worthwhile.
Absolutely. About 14 years
On 07/21/2014 05:36 PM, Clayton Coleman wrote:
It's very easy to be a pessimist or a cynic. Very little risk is
involved. It doesn't take any cojones to sit in a comfy chair and
email snarky comments. If you are optimistic about a project and it
fails, your peers may see your actions as a
On 07/19/2014 09:23 PM, Robert Bruninga wrote:
I cannot believe that. The equilibrium of a nominally black (solar panels
on all sides) spacecraft is something like about 0 to 30 C (32F to 90F) a
very benign operational range. The only time you DO have thermal issues is
when you DO have
On 07/20/2014 03:45 AM, John / NS1Z wrote:
Is there some reason why a digital signal cannot be passed thru an
analog/linear transponder? What goes in is what comes out. It seems the
lack of transponder bandwidth limits the digital signal experimenter...
Maybe that is why commercial
On 07/20/2014 03:45 AM, John / NS1Z wrote:
Is there some reason why a digital signal cannot be passed thru an
analog/linear transponder? What goes in is what comes out.
I forgot to mention that a FM repeater is not a linear transponder.
Although FM is constant envelope and a FM RF power
On 07/19/2014 09:23 PM, Robert Bruninga wrote:
Yes, but with who? 95% of everyone in view is more than 45 degrees OUT of
the main beam. Directional antennas have zero value on LEO birds that need
to serve everyone in view at the same time. And if you only serve those in
the main beam, then
On 07/20/2014 06:10 AM, Thomas Doyle wrote:
- What the majority wants is more important than any individual want.
How do you determine what the majority wants.
- Voting
The results of an election are strongly determined by who gets to vote.
If you poll the tiny fraction of the amateur
On 07/20/2014 06:13 AM, Simon Brown wrote:
John,
If both side have good Doppler correction then it can be done, but you have
to choose the correct mode as there are other issues even if the Doppler
correction is perfect, especially when the range is changing at its maximum,
for example as
On 07/20/2014 06:27 AM, Rick Walter wrote:
I was not going to post but since no one else has, I thought there needs to
be a correction to a statement made in case some younger people are reading
the thread.
Phil said:
Good analogy, actually. They returned to the moon six times
On 07/20/2014 08:09 AM, Graham Shirville wrote:
Hi Phil,
The reality is, even with no battery heater on FUNcube-1 we seem to have
an acceptable battery temperature of between 0 and +5C. The temp sensor
is, of course, actually external to the battery itself.
You must be using different solar
On 07/20/2014 10:00 AM, Paul Stoetzer wrote:
A good number of
amateur radio operators are only vaguely aware of the amateur
satellite program and consider it to be quite esoteric.
Precisely. Huge az/el yagi arrays don't help that image either.
Nor does an occasional, brief, noisy pass of an
On 07/20/2014 08:00 PM, Gus wrote:
I'd hazard to guess that the 'average' shack has multi-mode HF
capability, along with VHF/UHF FM. Some lesser number of 'average'
shacks will have multi-mode VHF/UHF, or could readily acquire that
capability without too much expenditure in resources (time,
On 07/18/2014 12:08 PM, Joseph Spier wrote:
Fox-1C is the third of four Fox-1 series satellites under
development, with Fox-1A and RadFXsat/Fox-1B launching through the
NASA ELANA program. Fox-1C will carry an FM repeater system for
amateur radio for use by radio hams and listeners worldwide.
On 07/19/2014 12:28 PM, Paul Stoetzer wrote:
Are FM repeater satellites what we all want in orbit? No. Personally,
I'd like a Mode J linear transponder in a sun synchronous circular
orbit of about 2,000km (if we can't get anything to HEO).
Getting a launch opportunity is difficult and
On 07/19/2014 01:42 PM, Andrew Glasbrenner wrote:
Getting a launch opportunity is difficult and expensive. Going digital is
not.
The Fox satellites each have four designated experiment cards. Assemble a
team and pitch a proposal for 1D, or 1C if you can do it in a hurry.
73, Drew KO4MA
On 07/19/2014 02:04 PM, Jerry Buxton wrote:
other three would be ready to fly if other opportunities came up. If
you're going to spend the time developing them, why not partner for free
launches (ELaNa) for more than one? The opportunities for an FM
transponder and educational outreach are
On 07/19/2014 03:32 PM, Jerry Buxton wrote:
But you arguing about something that has already happened. That makes
no sense.
None of the Fox satellites have yet flown, so they haven't already
happened.
Why did the U.S. go back to the moon so many times? I don't know. But
we did, and that
Like most people here I have an email address on amsat.org that
automatically relays to my primary email address.
I get a **lot** of spam via this path; a quick check shows that fully 96
out of 244 recent spam messages (as classified by Gmail) received at my
primary email address had been
On 04/22/2014 03:40 PM, Paul Stoetzer wrote:
When FUNcube was first launched, I went out to listen to it on the first
pass that I was home for (orbit #11 I believe). Since I live in an
apartment building, I have to go outside to hear most satellite passes.
I recorded the audio on my normal MP3
I haven't done anything with AO-73, but I understand it's transmitting
the FEC format I originally designed for AO-40.
How well is it working? What fraction of the frames are successfully
decoded? How bad is the fading? I designed my format specifically for
the spin fading on AO-40, and if the
On 03/26/2014 12:28 PM, Howie DeFelice wrote:
All Inmarsat satellites though the F-3 series have been in inclined
orbits since beginning of life.
Ah so, I was wondering if that might be the case because the user
antennas are mobile and have broad patterns to begin with. What is their
nominal
Finally, (some) technical details, though still not as many as I'd like.
https://www.facebook.com/permalink.php?story_fbid=740971779281171id=17856654999stream_ref=10
The original analysis was based either on a round trip time measurement
or a reported transmitter power, which depends on
Kimberly and I picked it up visually here in San Diego about a minute
before staging. Because of the high inclination (reportedly 123 degrees)
it was faint and far away, but it was unmistakable in binoculars despite
local light pollution. The plume was gradually broadening as it rose
into thinner
On 10/31/2013 01:44 AM, Bryce Salmi wrote:
I would imagine that if your AMSAT.org email address is public and
posted online then spammers could email it which then gets forwarded and
might look like a trusted email to your email provider and not flagged
as spam.Just a thought.
My amsat.org
I'm one of several adult mentors to a local high school ham club that's
been designing and flying balloons. We are designing a high speed 70cm
digital downlink for a future payload. One of my major concerns is
frequency selective multipath fading in the 1 MHz bandwidth I plan to
use as the balloon
On 07/09/2013 06:45 PM, Stefan Wagener wrote:
Well,
If I am not mistaken, the copyright is still with AMSAT. Certainly would
be nice to get permission from the AMSAT office before the electronic
distribution goes ahead!
Last time I asked, no one seemed to mind.
Phil
On 07/09/2013 04:43 PM, W7TYN wrote:
Phil, Thank You very much for your excellent effort to digitize and
keep AMSAT Publications. I have been active with AMSAT since the early
1970 and do have some some publications. I will inventory my collection
and if they are not on your fine list I will
On 06/28/2013 11:03 AM, Les Rayburn wrote:
Does AMSAT offer compilations (back issues) of the AMSAT Journal in PDF
format on CD, similar to the way that the ARRL and other organizations
do with their publications?
A while ago I scanned my own collection of *old* AMSAT publications,
from
On 03/08/2013 01:31 PM, PA3GUO wrote:
Things I learned and included in my software:
- thresholds are needed to avoid the system oscillating around a target position
- corrections need to be made due to overshoot (after a stop command the rotor
takes time to actually stop
These are exactly
On 03/08/2013 12:08 AM, Gus wrote:
Still, it sure sounds interesting! What do you think it would cost to
put one together?
Dunno. I'd have to build one. It would run from a DC supply, because the
inverter would convert that to AC at the necessary voltage and
frequency. Because the rotor
Just noticed this thread and caught up.
While rotor controllers are indeed a dime a dozen, I think we could do a
lot better than any of them.
Your typical Yaesu/Kenpro rotor uses a 24V AC 2-phase induction motor.
The control box applies 50/60 Hz AC directly to one winding and to the
other
On 2/26/12 3:02 AM, i8cvs wrote:
If you are interested in a very simple but effective Single to 3-PHASE
Power Converter for azimuth and elevation motors currently used for
EME, look at this web page made by John Yurek, K3PGP
http://www.k3pgp.org/3phconv.htm
This is a classic rotary phase
On 2/25/12 9:24 PM, Joe Fitzgerald wrote:
On 2/25/2012 4:25 PM, Phil Karn wrote:
If it really was a 3-phase induction motor then there *had* to be some
sort of phase shift at least to start it.
Of course you are right. I found a schematic of their controller
http://www.ecse.rpi.edu
On 2/25/12 6:46 AM, Joe Fitzgerald wrote:
controller, but it was not particularly sophisticated. They simply
pulsed 60Hz AC from a 24V transformer when they wanted to accelerate or
slow down. I am not exactly sure how they generated torque since there
was no evidence that they did anything
On 2/23/12 2:51 PM, Tim Cunningham wrote:
I have rewound a few of these motor coils and a #24 to #26 gauge enamel
wire should work. A #22 gauge enamel wire would be too large and you
would not be able to wind the same number of turns.
It is the breakdown of the enamel due to wire heating
On 2/24/12 11:58 AM, Joe Fitzgerald wrote:
Your fans will not be completely happy until your controller runs a
state-space model of the motor/antenna system, with software that is
careful to generate acceleration and jerk limited commands such that
mechanical resonances are not excited.
On 2/23/12 6:31 AM, David Palmer KB5WIA wrote:
Question to the list: does anyone have a G5500 azimuth rotator with a
working motor available for parts? Or any other ideas for
replacement?
You might consider rewinding it yourself. I did that with one of mine
some years ago, and it worked
On 2/23/12 8:29 AM, WA6FWF wrote:
Hi David,
As you found out shaded pole motors do not pull more current when
they stall, they
actually pull less and so they wont blow the fuse, they just sit and cook.
Are you sure these are shaded-pole motors? They're designed for a
single-phase supply
On 2/23/12 12:30 PM, Len Revelle wrote:
My Hi-Q screwdriver antenna uses a resettable fuse that opens when the
drive hits top or bottom, takes a few minutes to reset after the current
subsides, and you save the motor. Seems the simplest fix to the rotor.
Yes, it does. Do you know the rating of
On 8/22/11 9:18 PM, Greg D. wrote:
Ah, interesting. So, values around +/- 0 mean that the battery is
(or thinks it is) fully charged, and the satellite is running on just
the solar panels. Since that happens pretty quickly after start-up
(low MET values), that certainly supports the
On 8/24/11 8:11 PM, R Oler wrote:
http://onorbit.com/node/3709
Thrusters are necessary for orbit control, but for attitude control
(which I think we really need) you'd *really* prefer something that
doesn't consume a fuel.
These attitude control systems come in basically two types:
On 8/20/11 6:40 AM, Ronald G. Parsons wrote:
With these two changes, although the Doppler correction may drift off,
it does so very smoothly, which I assume allows the decoding of the BPSK
data to be more accurate.
Yes, the closer you keep it the better it'll work. Errors of up to +/-
50 Hz
On 8/19/11 7:51 AM, Gregg Wonderly wrote:
What kind of digital are you suggesting? Voice and data both? A
digital path from anywhere on the planet to the appropriate ground
station is easily doable with some documentation of the ground stations.
Digital voice would be the easiest to support
On 8/18/11 8:15 AM, Patrick Strasser OE6PSE wrote:
For decoding please be aware that I/Q via sound interfaces has a weak
spot at the centre frequency. The interfaces all have a high pass
characteristic below like 30Hz, which means the resulting spectrum has a
Yes, I'm familiar with this. I
On 8/18/11 5:47 AM, Bob Bruninga wrote:
The problem with LEO satellites is that a nadir facing antenna does give
great gain directly overhead ground stations, but only for about the center
2 minutes of only the one direct overhead pass a day. The problem with
facing antennas down on a LEO
On 8/17/11 5:29 PM, Mike Schaffer wrote:
What is the official AMSAT/ARISSat1 team finding on the ARISSat-1 70cm
quarter-wave
receive antenna on the bottom of the satellite? I have not heard updated news
about that
since the jettison occurred.
As far as I know, and this is *NOT* the
On 8/18/11 11:03 AM, JoAnne Maenpaa wrote:
Yeah, we still have dreams! At various times it had been called AMSAT-Eagle,
Phase IV Lite, C-C Rider, and other things. You'll notice from the dates on
these papers how long we've had this dream of a millions dollar rideshare
with a millions dollar
On 8/18/11 6:59 AM, Alan P. Biddle wrote:
Ron,
That behavior is common around TCA, Time of Closest Approach. At that time
everything is changing rapidly, and slight errors in QTH position, system
clock, and Keps can be magnified.
As everybody knows, even tiny errors in the Keplerian mean
On 8/18/11 10:31 PM, Dave Guimont wrote:
That's why the quadrifilars work so well. I measured the pattern some
time back, and the beam width is about 140 degrees
Yes, something with that kind of beamwidth would be ideal on the
nadir-facing surface of a stabilized satellite in low earth
On 8/17/11 1:36 PM, Mark L. Hammond wrote:
In any event, Phil...THANK YOU for making this code real. I have
seen it print data when the signal was visibly in the dirt which is
impressive and fun to see.
You're most welcome. It was a lot of work mainly because there were so
many options in
On 8/17/11 4:24 PM, Alan Cresswell wrote:
That's interesting. I have collected all my passes on the TS2000 with the
AGC on and set to the longest setting. This is mainly because I often
record the signal level every 0.5 seconds during a pass which requires the
AGC to be on and the longest
I forgot to offer some advice when receiving the ARISSat-1 BPSK-1000
telemetry beacon: turn off your receiver AGC if at all possible. If you
can only choose between fast and slow, pick slow. If this causes a large
variation in audio level, reduce the gain to avoid clipping on the
peaks. A sound
On 8/14/11 6:11 PM, Anthony Monteiro wrote:
Yes, Zinc dendrites will form also if the battery is
overcharged but we should not be able to do that on
ARISSat-1 so only the silver ones should be an issue.
Oh, so they form on both plates. Interesting. Charging the battery
plates out zinc metal
On 8/14/11 4:34 PM, Jim Cameron KC9PXZ wrote:
I have a question, I don't have a SSB rig so I am FM only, wish I could
decode telemetry and CW that would be a blast! but as I understand I
can't with just FM, or am I wrong?
That's correct. It's just not possible to design a highly
On 8/14/11 3:18 PM, Anthony Monteiro wrote:
I think the explanation is that the battery experienced a
significant event on Aug 11 where it lost the electrolyte
in one or more cells. If this is true, the bad news is
that it will no longer hold a charge and will not operate
in eclipse any
On 8/14/11 11:31 AM, Burns Fisher wrote:
What about another strategy? Suppose we did exactly what the battery was
spec'ed for: Deep cycles.
Almost every type of battery does better with shallow cycles than deep
cycles. So this is almost certainly true for Ag/Zn as well. These
batteries just
On 8/10/11 8:24 PM, Tom Azlin N4ZPT wrote:
I have a Fun Cube Dongle so I would Phil. Thanks and 73, Tom n4zpt
Okay, everybody make and keep your wideband I/Q recordings and I'll work
on an enhancement to my demodulation/decoding software to process them.
It may not run in real time on slower
On 8/11/11 8:46 PM, Gould Smith wrote:
Kenneth Ransom, N5VHO has plotted the battery min/max for the last 8 days. We
see that the battery voltage is decreasing at a faster rate than expected.
Kenneth's graph can be found on the arissat1.org site under FAQ
On 8/13/11 6:11 PM, Dave Guimont wrote:
How about you designing circuitry/program to charge cells individually
rather than the battery. Or has that been tried??
That's a great idea; I wish I thought of it first, but it was Lou
McFadden W5DID who published a paper at the AMSAT Symposium a few
On 8/8/11 5:23 AM, g0...@aol.com wrote:
I've been tracking doppler by hand. Seems to work OK but it's very
important to keep the CW in the 'blue' window. I would think jumps
would not be good. Perhaps frequent doppler updates. - So very small
jumps.
Jumps per se are not a problem. I.e., if
On 8/8/11 6:09 AM, Alan P. Biddle wrote:
Rich,
Orbital dynamics are not all that intuitive.
That's absolutely right. Some historical trivia: even NASA tripped over
this in the early days. When the Gemini IV crew tried to rendezvous with
their spent booster, they kept missing. They were
On 8/9/11 4:56 AM, Alan P. Biddle wrote:
when the satellite is in daylight or eclipsed. A spacecraft is often
illuminated when the ground track is in darkness, though the passes you
mentioned would be in eclipse.
It's very easy to tell just by looking at a tracking map whether a
spacecraft
It's been suggested that I modify my ARISSat-1 BPSK-1000 telemetry
demodulator/decoder to accept wideband quadrature (I Q) recordings
like those produced by most of the software defined radios out there.
This is fundamentally not that hard, but first I need some information.
How many people
On 8/6/11 8:55 PM, James wrote:
Thank you for your informative contribution..
Anyone with a real answer?
Well, an educated guess can be made by looking at a plot of ISS altitude
vs time:
http://www.heavens-above.com/IssHeight.aspx
The ISS is periodically reboosted, accounting for the
I note that, lifetime-wise, this deployment delay has actually left us
much better off. The ISS had some big reboosts in June and is now at an
altitude of about 387 km. Had we been deployed in February as originally
scheduled, the ISS would have been at an altitude of only about 352 km.
73, Phil
On 8/7/11 12:47 AM, Jeff Yanko wrote:
If anything, maybe this calls for another Chicken Little Contest to see
who can come the closest to predicting re-entry.
Absolutely!
As an old friend of mine used to say about his favorite game of
backgammon, this will require a combination of luck and
On 8/7/11 5:59 AM, N0JY wrote:
Phil,
My Windows 7 PC with Realtek onboard sound set at 48kHz seems quite
happy, having captured and forwarded 155 frames while I slumbered...
So one final, please tell me what you think about the tuning (see
Well, you can't argue with success!
Phil
On 8/7/11 3:40 AM, Nico Janssen wrote:
Actually the TLEs give you the values for the drag (First Time
Derivative of the Mean Motion) and for the ballistic coefficient
(BSTAR drag term). Note that in the TLEs the definition of the
ballistic coefficient is the inverse of Phil's definition, i.e.
On 8/3/11 11:28 AM, Patrick STODDARD (WD9EWK/VA7EWK) wrote:
If You are trying to confirm four courners , It's going to take You several
minutes to correctly confirm 4 different coordinates . Just a thought .
Dave will only need to have the GPS at *one* location, which will be
the
On 8/7/11 7:07 PM, Daniel Schultz wrote:
Anyone who has tried to find an engineering job recently knows that there is
no shortage of engineers, but lazy journalists keep reporting about a crisis
in STEM education and how we need to inspire the next generation to study
science and engineering.
On 8/6/11 9:54 AM, Nigel A. Gunn, W8IFF/G8IFF wrote:
JUNO
1 37773U 11040A 11217.69136966 +.2254 -71274-5 +0-0 0 00015
2 37773 028.7890 020.5966 0025801 264.4436 221.8704 16.2621444202
These elements don't make sense. This object is in a low circular orbit,
while Juno is on an
On 8/6/11 9:31 AM, N0JY wrote:
I'm having trouble getting telemetry.
Jerry, is this a night-side pass with the satellite in low power mode?
The coding is not optimal for a signal that's present only a small
fraction of the time, as it takes 16.384 sec at AOS to fill the pipe
in the
On 8/6/11 8:23 AM, George Henry wrote:
It doesn't appear that the satellite has any active or passive attitude
control
system.
Correct.
I have heard that the spin should eventually settle around the same
axis as the antenna, but is there any reasonable hope that that would happen
On 8/6/11 6:09 AM, Alan P. Biddle wrote:
Hi,
made/purchased, due to the numerous running production mods. There have been
a few reports of people being unable to print the BPSK telemetry, even
though the signal is good, and the CW decodes well.
I just thought of another possibility. I
On 8/4/11 8:04 PM, Sion Chow Q. C. (9W2QC) wrote:
2. Does the CW beacon needs to be really +/- 100 Hz of the yellow
line? The reason for this is that I would like to see how much offset
should I apply to doppler control, for possible automated reception.
Tuning the CW beacon to 500 Hz
On 8/5/11 11:03 AM, Burns Fisher wrote:
I saw on one of the NASA announcements that the snarffled 70cm antenna would
mean no commanding of the bird. (This was probably before it was realized
that that receive actually seems to work). But the question I have is
whether there IS some
On 8/5/11 2:14 PM, Nigel A. Gunn, W8IFF/G8IFF wrote:
As many have said before.
Perhaps we should get away from the American system of allocating Oscar
numbers and use the real world name that the builders and launch
agencies use.
It's longstanding tradition to give a spacecraft a pre-launch
On 8/5/11 2:33 PM, Ted wrote:
Americans built it. They should have the naming rights.
Just because some Russians threw it off their space ship does not give them
the right to name it (it just gives them the right to break it!)
Americans built the spacecraft BUS. That's most of the
On 8/3/11 8:21 PM, Jim Jerzycke wrote:
At least AO-40 had a usable life for some. This thing is just another
squawk box in space, like all the student satellites that are using
the Amateur Radio frequencies for a free downlink.
ARISSat is still a little more than that. It's a good
On 8/3/11 7:24 PM, Alan Cresswell wrote:
Another ARISSat-1 pass over ZL. 0206UT, 27 deg.
Good telemetry but nothing on the transponder.
19 data frames and 23 Kursk frames uploaded.
Could you hear any receiver noise in the transponder passband?
___
On 8/3/11 8:39 PM, g0...@aol.com wrote:
Apx. 6 second spin period puts deep nulls in transmitted signal. -
Not sure if this is due to linear polarisation of my receive antenna
or blockage from spacecraft.
Since we don't have video of the actual deployment we don't know how it
was turning at
On 8/3/11 9:28 PM, Andrew Glasbrenner wrote:
I was able to hear myself with as little as 1 watt on the 0425Z pass.
Antennas are a M2 CP42 on RHCP up, and a 10 element horizontal yagi
down. Sounded VERY good, and cycled on and off with the telemetry. I
also managed to grab 2 frames of tlm
On 8/3/11 5:56 PM, Burns Fisher wrote:
Thanks to everyone who posted pictures. I think Phil Karn's picture number
9204 is particularly interesting. It almost looks like something coming
out of the collar and bending back and down away from the camera. Any
chance that is an antenna stuck
I'm interested in people's comments on the reliability of the BPSK-1000
digital link in the presence of the deep periodic fading that everyone
is reporting. This fading is probably because the spacecraft hasn't
settled down into a stable spin around its preferred spin axis (which
includes the
On 8/4/11 11:02 AM, George Henry wrote:
Correction: I don't recall the celebration of Gagarin's flight ever being a
SIGNIFICANT part of ARISSat-1's mission...
Although Gagarin's flight was undertaken at a time of intense and heated
competition with the United States, it was still a
I put a couple of snapshots of closeups of the 70 cm antenna on my
website. I can't do video grabs so they're simply photographs of the TV
screen.
This is just a directory of raw photographs, no thumbnails:
http://www.ka9q.net/ARISSAT/
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Oh, I forgot to mention. The ARISSat-1 beacon should be received on a 2m
SSB radio in USB mode, with any passband tuning set to nominal, and
continuously tuned for Doppler to keep the CW beacon coming out at an
audio pitch of 500 Hz. That will put the suppressed carrier of the BPSK
signal at 1500
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