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CX2SA > SATDIG 12.05.10 16:06l 974 Lines 31053 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: PC clock (i8cvs)
2. Re: PC clock (Mark L. Hammond)
3. Re: PC clock (Edward R Cole)
4. Maui on FM sats (Lee Ernstrom)
5. AMSAT stamps ebay 100% to amsat (Bob- W7LRD)
6. Re: Maui on FM sats (Lee Ernstrom)
7. Drifting Satellite Threatens US Cable Programming
(W4ART Arthur Feller)
8. Re: PC clock (Greg D.)
9. Re: Happy 5th Birthday to HAMSAT (William Leijenaar)
10. Re: PC clock (Erich Eichmann)
11. Long Distance Software Patch (Rich Dailey)
12. Re: Happy 5th Birthday to HAMSAT (Tony Langdon)
13. Re: PC clock (i8cvs)
14. Atlantis launch at Dayton? (Bill ONeil)
15. Call for Papers--2010 ARRL/TAPR Digital Communications
Conference (Ford, Steve, WB8IMY)
16. Tone on AO-51? (Luc Leblanc)
----------------------------------------------------------------------
Message: 1
Date: Tue, 11 May 2010 22:07:22 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: PC clock
To: "Greg D." <ko6th_greg@xxxxxxx.xxx>, <W7IN@xxxxxxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <000001caf145$d9e0b460$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
To: <w7in@xxxxxxx.xxx>
Cc: <amsat-bb@xxxxx.xxx>
Sent: Tuesday, May 11, 2010 7:47 AM
Subject: [amsat-bb] Re: PC clock
>
> Hi Larry,
>
> Ok, I understand the need for an accurate clock, though I believe you're
> expectations for being able to track an overhead pass is pushing the
> limits of orbital prediction pretty hard. Another ham I know locally
> tried this, and ultimately gave up. His issue was not one of clock
> accuracy, but of Keps and the mathematics behind them.
>
>
> Greg KO6TH
>
Hi Greg, KO6TH
When the software calculate the Az and the El of the satellite at the right
time with an accurate clock then it send a command to the rotators but the
antennas takes a certain time to go in that calculated position and when the
antennas are finally there then the satellite is already in another position
far advanced in it's orbital path particularly when the satellite pass is
overhead.
I dont think you want to run the motors every 5 or 10 seconds othervise your
control relays will work as a machine-gun
So the issue is not on clock accuracy or Keps or mathematics behind them but
it is on the tracking system that we normally use to mimichaise the
satellite position with a phase difference between the satellite calculated
position and the actual antenna position when the traching command is sent
to the motors.
If you go over the roof and you follow the ISS by naked eye you will realize
that your antenna pointing is always a little bit behind the ISS position in
the sky and so a very accurate clock to track a LEO satellite is meaning
less particularly using high gain antennas with a narrow main lobe.
73" de
i8CVS Domenico
------------------------------
Message: 2
Date: Tue, 11 May 2010 16:25:38 -0400
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: PC clock
To: i8cvs <domenico.i8cvs@xxx.xx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>, W7IN@xxxxxxx.xxx
Message-ID:
<AANLkTinrrZZD-_T4JluGefixhSym6VArCefWE-hGclG5@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hello Domenico,
The very excellent SatPC32 program "leads" so as to keep an accurate
pointing at a satellite. It has several adjustments for how often the
rotors are updated, gain consideration of the antennas in use, etc.
73,
Mark N8MH
On Tue, May 11, 2010 at 4:07 PM, i8cvs <domenico.i8cvs@xxx.xx> wrote:
> ----- Original Message -----
> From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
> To: <w7in@xxxxxxx.xxx>
> Cc: <amsat-bb@xxxxx.xxx>
> Sent: Tuesday, May 11, 2010 7:47 AM
> Subject: [amsat-bb] Re: PC clock
>>
>> Hi Larry,
>>
>> Ok, I understand the need for an accurate clock, though I believe you're
>> expectations for being able to track an overhead pass is pushing the
>> limits of orbital prediction pretty hard. ?Another ham I know locally
>> tried this, and ?ultimately gave up. ?His issue was not one of clock
>> accuracy, but of Keps and the mathematics behind them.
>>
>>
>> Greg ?KO6TH
>>
> Hi Greg, KO6TH
>
> When the software calculate the Az and the El of the satellite at the right
> time with an accurate clock then it send a command to the rotators but the
> antennas takes a certain time to go in that calculated position and when the
> antennas are finally there then the satellite is already in another position
> far advanced in it's orbital path particularly when the satellite pass is
> overhead.
>
> I dont think you want to run the motors every 5 or 10 seconds othervise your
> control relays will work as a machine-gun
>
> So the issue is not on clock accuracy or Keps or mathematics behind them but
> it is on the tracking system that we normally use to mimichaise the
> satellite position with a phase difference between the satellite calculated
> position and the actual antenna position when the traching command is sent
> to the motors.
>
> If you go over the roof and you follow the ISS by naked eye you will realize
> that your antenna pointing is always a little bit behind the ISS position in
> the sky and so a very accurate clock to track a LEO satellite is meaning
> less particularly using high gain antennas with a narrow main lobe.
>
> 73" de
>
> i8CVS Domenico
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. 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
>
--
Mark L. Hammond [N8MH]
------------------------------
Message: 3
Date: Tue, 11 May 2010 12:58:16 -0800
From: Edward R Cole <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: PC clock
To: "i8cvs" <domenico.i8cvs@xxx.xx>, "Greg D."
<ko6th_greg@xxxxxxx.xxx>, <W7IN@xxxxxxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <201005112058.o4BKwGt5030416@xxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 12:07 PM 5/11/2010, i8cvs wrote:
>----- Original Message -----
>From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
>To: <w7in@xxxxxxx.xxx>
>Cc: <amsat-bb@xxxxx.xxx>
>Sent: Tuesday, May 11, 2010 7:47 AM
>Subject: [amsat-bb] Re: PC clock
> >
> > Hi Larry,
> >
> > Ok, I understand the need for an accurate clock, though I believe you're
> > expectations for being able to track an overhead pass is pushing the
> > limits of orbital prediction pretty hard. Another ham I know locally
> > tried this, and ultimately gave up. His issue was not one of clock
> > accuracy, but of Keps and the mathematics behind them.
> >
> >
> > Greg KO6TH
> >
>Hi Greg, KO6TH
>
>When the software calculate the Az and the El of the satellite at the right
>time with an accurate clock then it send a command to the rotators but the
>antennas takes a certain time to go in that calculated position and when the
>antennas are finally there then the satellite is already in another position
>far advanced in it's orbital path particularly when the satellite pass is
>overhead.
>
>I dont think you want to run the motors every 5 or 10 seconds othervise your
>control relays will work as a machine-gun
>
>So the issue is not on clock accuracy or Keps or mathematics behind them but
>it is on the tracking system that we normally use to mimichaise the
>satellite position with a phase difference between the satellite calculated
>position and the actual antenna position when the traching command is sent
>to the motors.
>
>If you go over the roof and you follow the ISS by naked eye you will realize
>that your antenna pointing is always a little bit behind the ISS position in
>the sky and so a very accurate clock to track a LEO satellite is meaning
>less particularly using high gain antennas with a narrow main lobe.
>
>73" de
>
>i8CVS Domenico
>
>
>
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. 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
Good point! I guess if we had software that could provide a position
slightly in advance of the satellite so the tracking could be a
series of short drifts thru the beam of the antennas...that would be
ideal. Also much more complicated since the lead time/angle would
vary by satellite pass, and ground station antenna
parameters. Tracking Leo satellites on s-band with a two-foot dish
can be demanding considering the narrow beamwidth. Fortunately, one
does not need that much gain for Leos.
When I track the Moon, manually, this is what I do. But the Moon
apparent motion in the sky is about 15-degrees/hour in azimuth so
with 16-degree 2m antennas it only requires repointing 2-3 times per
hour. At 1296 my eme antenna beamwidth is 3-degrees so keeping
peaked within 1-dB requires much more frequent movement (10 or more
times/hour). Fortunately, most auto-track sw has input for how often
to command the rotators.
My 16-foot dish actuators rotate the dish fairly slow (90-deg/5-min),
so it takes some time for repointing. I can resolve 0.1 degree movement.
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-600w, 432-100w, 1296-60w, 3400-fall 2010
DUBUS Magazine USA Rep dubususa@xxxxxxx.xxx
======================================
------------------------------
Message: 4
Date: Tue, 11 May 2010 19:33:42 -0600
From: "Lee Ernstrom" <iamsavedbygrace@x.xxx>
Subject: [amsat-bb] Maui on FM sats
To: <amsat-bb@xxxxx.xxx>
Message-ID: <BLU0-SMTP8182105F473308BBB3A595ADFB0@xxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Hi everyone,
I will be in Maui on Wednesday and Thursday and will have my arrow
antenna and handheld. I haven't checked the sats yet to see when the
passes are. Any suggestions?
WA7HQD
Lee Ernstrom
------------------------------
Message: 5
Date: Wed, 12 May 2010 03:02:15 +0000 (UTC)
From: Bob- W7LRD <w7lrd@xxxxxxx.xxx>
Subject: [amsat-bb] AMSAT stamps ebay 100% to amsat
To: amsat-bb@xxxxx.xxx
Message-ID:
<840590415.16496151273633335758.JavaMail.root@xxxxxxx.xxxxxxxxxx.xx.xxxx.xxxxx
xx.xxx>
Content-Type: text/plain; charset=utf-8
In the spirit of the Dayton $5000 challenge I am offering on Ebay my AMSAT
framed stamps.? 100% of the proceeds go to AMSAT.? I expect nothing less
than a spirited bidding battle of these stamps.
http://shop.ebay.com/?_from=R40&_trksid=p3984.m570.l1313&_nkw=amsat+stamps&_sa
cat=See-All-Categories
73 Bob W7LRD
------------------------------
Message: 6
Date: Tue, 11 May 2010 22:00:12 -0600
From: "Lee Ernstrom" <iamsavedbygrace@x.xxx>
Subject: [amsat-bb] Re: Maui on FM sats
To: <amsat-bb@xxxxx.xxx>
Message-ID: <BLU0-SMTP7344057EFB2B0EAE126546ADFB0@xxx.xxx>
Content-Type: text/plain; charset="us-ascii"
I'm not sure where I am staying. My daughter is a flight attendant for
US Air and my decision to go to Maui has been a last minute one from her
invitation just a few hours ago. On Wednesday morning EARLY I will be
flying from SLC to PHX where I will join my daughter and we will fly
directly to Maui. For her it is a working trip, and for me, a chance to
just get away from reality and possibly play satelites. The radio and
antenna are packed up and ready to go. When I get a chance I will check
the passes and hopefully be able to post them here. I still have some
last minute prep to do. I sure wish AO-51 was available for V/U while I
am there :(
WA7HQD
Lee Ernstrom
-----Original Message-----
From: Adrian Engele [mailto:aa5uk@xxxxx.xxxx
Sent: Tuesday, May 11, 2010 8:08 PM
To: Lee Ernstrom
Subject: Re: [amsat-bb] Maui on FM sats
Lee,
What part of the island are you staying on? Reason I ask there is a big
Volcano that will block the lower passed if you are on the Southern part
of the island. If you are towards Lahaina and Kaanapali you will have a
better chance to work the satellites.
I was on Mauai a few years ago and did not operate back then. I just
came back from Kaui and Oahu from a satellite DXPedition back in early
April and I had a great view to horizon. I worked mostly the SSB
satellites and was able to talk as far as Japan, Russia, Mexico, USA (as
far East as Athens GA). FM satellites will have small footprints and
the passes will be short.
AO51 will not be available unless you can work mode V/S:
May 10 - May 16
FM Repeater, V/S (See or Work Us at Dayton!)
Uplink: 145.880 MHz FM
Downlink: 2401.200 MHz FM
67 Hz PL Tone Required
AO27 will be a short pass, as well as SO50. I managed to work HO68 but
it is not always on over HI. I managed to ask to have it turned on over
HI during my trip.
Check your location and look, print out the passes and then look at an
elevation map. Unless you are on top of the Volcano or towards the North
Side you may be limited in your passes.
I just wanted to pass that along. Have a great time in Mauai, a really
fun island!
73, Adrian AA5UK
_____
From: Lee Ernstrom <iamsavedbygrace@x.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Tue, May 11, 2010 8:33:42 PM
Subject: [amsat-bb] Maui on FM sats
Hi everyone,
I will be in Maui on Wednesday and Thursday and will have my arrow
antenna and handheld. I haven't checked the sats yet to see when the
passes are. Any suggestions?
WA7HQD
Lee Ernstrom
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. 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
------------------------------
Message: 7
Date: Tue, 11 May 2010 14:14:50 -0400
From: W4ART Arthur Feller <afeller@xxxx.xxx>
Subject: [amsat-bb] Drifting Satellite Threatens US Cable Programming
To: Undisclosed recipients: ;
Message-ID: <313D393B-77D4-4834-BA3A-E401E739A155@xxxx.xxx>
Content-Type: text/plain; charset=us-ascii
http://www.nytimes.com/aponline/2010/05/11/technology/AP-Out-of-Control-Satell
ite.html?_r=1
73, art.....
W4ART Arlington VA
------------------------------
Message: 8
Date: Tue, 11 May 2010 21:47:23 -0700
From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
Subject: [amsat-bb] Re: PC clock
To: <domenico.i8cvs@xxx.xx>, <w7in@xxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <BLU133-W19AC3B6FCC5BEB627356C5A9FB0@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Dominico,
The local ham I referred to was trying to drive his rig's Doppler open-loop,
based only in time and keps, and found that he could get close enough for
FM, but not quite good enough for some of the more frequency-sensitive
modes. Antennas (his and mine) aren't sharp enough to need such precise
tracking, but I understand about the antenna lag. My own system has a
granularity of 6 degrees Az (10 El), and even so it gets busy around TCA.
But fortunately, few passes are so high as to cause motor or relay problems.
My bigger problem, actually, is that my controller doesn't (yet) know about
flipped operation, so passes that cross the Zenith to North line have that
annoying 60-second gap. But the fix is a matter of software, and some time
to write it.
Thanks for your words of advice. Always appreciated.
Greg KO6TH
> From: domenico.i8cvs@xxx.xx
> To: ko6th_greg@xxxxxxx.xxxx W7IN@xxxxxxx.xxx
> CC: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Re: PC clock
> Date: Tue, 11 May 2010 22:07:22 +0200
>
> ----- Original Message -----
> From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
> To: <w7in@xxxxxxx.xxx>
> Cc: <amsat-bb@xxxxx.xxx>
> Sent: Tuesday, May 11, 2010 7:47 AM
> Subject: [amsat-bb] Re: PC clock
> >
> > Hi Larry,
> >
> > Ok, I understand the need for an accurate clock, though I believe you're
> > expectations for being able to track an overhead pass is pushing the
> > limits of orbital prediction pretty hard. Another ham I know locally
> > tried this, and ultimately gave up. His issue was not one of clock
> > accuracy, but of Keps and the mathematics behind them.
> >
> >
> > Greg KO6TH
> >
> Hi Greg, KO6TH
>
> When the software calculate the Az and the El of the satellite at the right
> time with an accurate clock then it send a command to the rotators but the
> antennas takes a certain time to go in that calculated position and when the
> antennas are finally there then the satellite is already in another position
> far advanced in it's orbital path particularly when the satellite pass is
> overhead.
>
> I dont think you want to run the motors every 5 or 10 seconds othervise your
> control relays will work as a machine-gun
>
> So the issue is not on clock accuracy or Keps or mathematics behind them but
> it is on the tracking system that we normally use to mimichaise the
> satellite position with a phase difference between the satellite calculated
> position and the actual antenna position when the traching command is sent
> to the motors.
>
> If you go over the roof and you follow the ISS by naked eye you will realize
> that your antenna pointing is always a little bit behind the ISS position in
> the sky and so a very accurate clock to track a LEO satellite is meaning
> less particularly using high gain antennas with a narrow main lobe.
>
> 73" de
>
> i8CVS Domenico
>
>
>
_________________________________________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with
Hotmail.
http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID2832
6::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5
------------------------------
Message: 9
Date: Wed, 12 May 2010 01:41:14 -0700 (PDT)
From: William Leijenaar <pe1rah@xxxxx.xxx>
Subject: [amsat-bb] Re: Happy 5th Birthday to HAMSAT
To: amsat-bb@xxxxx.xxx
Message-ID: <650802.69446.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Hi Domenico
Thanks for the flowers.
Hopefully we can get some more linear transponders in orbit in the future.
Besides the small mode-UV that I have here on the shelf I am working on a
mode-LS version as well (CubeSat size ofcourse).
Also on?my bench is a credit card sized?2m-70cm FM transponder, which still
needs some time to get finalized.
73 de PE1RAH
William Leijenaar
>> Hi Hamsat Team,
>>
>> Thanks for building this great Amateur Satellite it is always a pleasure
>> to hear and work this great bird. I think when somebody will ask me what
>> my favorite linear transponder Satellite is VO-52 will be the first one
>> that crosses my mind.
>>
>> And as somebody already mentioned, lets hope it will be working for
>> another long time.
>>
>>
>> I'll buy some cake and candles to celebrate here birthday :))
>>
>> 73 Jan PE0SAT
>>
>
>Hi Jan, PE0SAT
>
>A great tanks also to William Leinejar PE1RAH who designed and built the
>Dutch transponder on board of VO-52.
>
>73" de
>
>i8CVS Domenico
------------------------------
Message: 10
Date: Wed, 12 May 2010 10:50:27 +0200
From: "Erich Eichmann" <erich.eichmann@xxxxxxxx.xx>
Subject: [amsat-bb] Re: PC clock
To: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <8F51DC80DC11432089AC0CC1DB0CACA9@xxxxxxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hello Mark, Domenico and others,
when SatPC32 updates the antenna positions it turns the antennas a half step
in front of the satellites position. The manual says:
"Under all tracking options, the rotors are activated with a precession of
one half step, either one half of the time interval or one half of the
tracking angle, to ensure that the satellite moves through the antenna
focus."
73s, Erich, DK1TB
----- Original Message -----
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
To: "i8cvs" <domenico.i8cvs@xxx.xx>
Cc: "AMSAT-BB" <amsat-bb@xxxxx.xxx>; <W7IN@xxxxxxx.xxx>
Sent: Tuesday, May 11, 2010 10:25 PM
Subject: [amsat-bb] Re: PC clock
Hello Domenico,
The very excellent SatPC32 program "leads" so as to keep an accurate
pointing at a satellite. It has several adjustments for how often the
rotors are updated, gain consideration of the antennas in use, etc.
73,
Mark N8MH
On Tue, May 11, 2010 at 4:07 PM, i8cvs <domenico.i8cvs@xxx.xx> wrote:
> ----- Original Message -----
> From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
> To: <w7in@xxxxxxx.xxx>
> Cc: <amsat-bb@xxxxx.xxx>
> Sent: Tuesday, May 11, 2010 7:47 AM
> Subject: [amsat-bb] Re: PC clock
>>
>> Hi Larry,
>>
>> Ok, I understand the need for an accurate clock, though I believe you're
>> expectations for being able to track an overhead pass is pushing the
>> limits of orbital prediction pretty hard. Another ham I know locally
>> tried this, and ultimately gave up. His issue was not one of clock
>> accuracy, but of Keps and the mathematics behind them.
>>
>>
>> Greg KO6TH
>>
> Hi Greg, KO6TH
>
> When the software calculate the Az and the El of the satellite at the
> right
> time with an accurate clock then it send a command to the rotators but the
> antennas takes a certain time to go in that calculated position and when
> the
> antennas are finally there then the satellite is already in another
> position
> far advanced in it's orbital path particularly when the satellite pass is
> overhead.
>
> I dont think you want to run the motors every 5 or 10 seconds othervise
> your
> control relays will work as a machine-gun
>
> So the issue is not on clock accuracy or Keps or mathematics behind them
> but
> it is on the tracking system that we normally use to mimichaise the
> satellite position with a phase difference between the satellite
> calculated
> position and the actual antenna position when the traching command is sent
> to the motors.
>
> If you go over the roof and you follow the ISS by naked eye you will
> realize
> that your antenna pointing is always a little bit behind the ISS position
> in
> the sky and so a very accurate clock to track a LEO satellite is meaning
> less particularly using high gain antennas with a narrow main lobe.
>
> 73" de
>
> i8CVS Domenico
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. 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
>
--
Mark L. Hammond [N8MH]
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. 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
------------------------------
Message: 11
Date: Wed, 12 May 2010 05:13:36 -0400
From: Rich Dailey <richdailey@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Long Distance Software Patch
To: amsat-bb@xxxxx.xxx
Message-ID: <7.0.0.16.2.20100512051007.023afc38@xxxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Voyager II is bit-flipping, engineers will attempt a fix from 8.6 billion
miles away.
Transmission delay is 13 hours. Wow.
http://www.spaceflightnow.com/news/n1005/11voyager2/
Rich, N8UX
------------------------------
Message: 12
Date: Wed, 12 May 2010 19:22:27 +1000
From: Tony Langdon <vk3jed@xxxxx.xxx>
Subject: [amsat-bb] Re: Happy 5th Birthday to HAMSAT
To: William Leijenaar <pe1rah@xxxxx.xxx>, amsat-bb@xxxxx.xxx
Message-ID: <4bea7380.107d8d0a.3363.ffffaafe@xx.xxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 06:41 PM 5/12/2010, William Leijenaar wrote:
>Hi Domenico
>
>Thanks for the flowers.
>
>Hopefully we can get some more linear transponders in orbit in the future.
Look forward to it, just getting 70cm SSB up and running here. I
suspect that I will be using this mode almost exclusively for
satellite operation.
73 de VK3JED / VK3IRL
http://vkradio.com
------------------------------
Message: 13
Date: Wed, 12 May 2010 12:01:43 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: PC clock
To: "Erich Eichmann" <erich.eichmann@xxxxxxxx.xx>, "Mark L. Hammond"
<marklhammond@xxxxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <000101caf1c0$d9c8a2a0$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Herich, DK1TB
When manually tracking a LEO satellite beginning from OSCAR-6 I
realized the same trick to point the antennas with an angle 5 to 10
degree in front of the satellite position.
The same technique is used by hunters to shoot down birds.
73" de
i8CVS Domenico
----- Original Message -----
From: "Erich Eichmann" <erich.eichmann@xxxxxxxx.xx>
To: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Cc: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, May 12, 2010 10:50 AM
Subject: [amsat-bb] Re: PC clock
> Hello Mark, Domenico and others,
> when SatPC32 updates the antenna positions it turns the antennas a half
step
> in front of the satellites position. The manual says:
>
> "Under all tracking options, the rotors are activated with a precession of
> one half step, either one half of the time interval or one half of the
> tracking angle, to ensure that the satellite moves through the antenna
> focus."
>
> 73s, Erich, DK1TB
>
> ----- Original Message -----
> From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
> To: "i8cvs" <domenico.i8cvs@xxx.xx>
> Cc: "AMSAT-BB" <amsat-bb@xxxxx.xxx>; <W7IN@xxxxxxx.xxx>
> Sent: Tuesday, May 11, 2010 10:25 PM
> Subject: [amsat-bb] Re: PC clock
>
>
> Hello Domenico,
>
> The very excellent SatPC32 program "leads" so as to keep an accurate
> pointing at a satellite. It has several adjustments for how often the
> rotors are updated, gain consideration of the antennas in use, etc.
>
> 73,
>
> Mark N8MH
>
> On Tue, May 11, 2010 at 4:07 PM, i8cvs <domenico.i8cvs@xxx.xx> wrote:
> > ----- Original Message -----
> > From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
> > To: <w7in@xxxxxxx.xxx>
> > Cc: <amsat-bb@xxxxx.xxx>
> > Sent: Tuesday, May 11, 2010 7:47 AM
> > Subject: [amsat-bb] Re: PC clock
> >>
> >> Hi Larry,
> >>
> >> Ok, I understand the need for an accurate clock, though I believe
you're
> >> expectations for being able to track an overhead pass is pushing the
> >> limits of orbital prediction pretty hard. Another ham I know locally
> >> tried this, and ultimately gave up. His issue was not one of clock
> >> accuracy, but of Keps and the mathematics behind them.
> >>
> >>
> >> Greg KO6TH
> >>
> > Hi Greg, KO6TH
> >
> > When the software calculate the Az and the El of the satellite at the
> > right
> > time with an accurate clock then it send a command to the rotators but
the
> > antennas takes a certain time to go in that calculated position and when
> > the
> > antennas are finally there then the satellite is already in another
> > position
> > far advanced in it's orbital path particularly when the satellite pass
is
> > overhead.
> >
> > I dont think you want to run the motors every 5 or 10 seconds othervise
> > your
> > control relays will work as a machine-gun
> >
> > So the issue is not on clock accuracy or Keps or mathematics behind them
> > but
> > it is on the tracking system that we normally use to mimichaise the
> > satellite position with a phase difference between the satellite
> > calculated
> > position and the actual antenna position when the traching command is
sent
> > to the motors.
> >
> > If you go over the roof and you follow the ISS by naked eye you will
> > realize
> > that your antenna pointing is always a little bit behind the ISS
position
> > in
> > the sky and so a very accurate clock to track a LEO satellite is meaning
> > less particularly using high gain antennas with a narrow main lobe.
> >
> > 73" de
> >
> > i8CVS Domenico
> >
> >
> >
> > _______________________________________________
> > Sent via AMSAT-BB@xxxxx.xxx. 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
> >
>
>
>
> --
> Mark L. Hammond [N8MH]
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. 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
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. 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
------------------------------
Message: 14
Date: Wed, 12 May 2010 05:46:06 -0700 (PDT)
From: Bill ONeil <kw8kw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Atlantis launch at Dayton?
To: amsat-bb@xxxxx.xxx
Message-ID: <603380.1552.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Anybody going to setup NASA TV at Dayton?
?
Bill
KW8KW
------------------------------
Message: 15
Date: Wed, 12 May 2010 10:19:13 -0400
From: "Ford, Steve, WB8IMY" <sford@xxxx.xxx>
Subject: [amsat-bb] Call for Papers--2010 ARRL/TAPR Digital
Communications Conference
To: "RTTY Reflector" <rtty@xxxxxxxxxx.xxx>, <amsat-bb@xxxxx.xxx>,
<vhf@xxxx.xxxxxxxx.xxx>, <psk31@xxxxxxx.xx.xxx.xx>,
<digitalradio@xxxxxxxxxxx.xxx>
Message-ID:
<145372871023544E98881538F29B1DFC01B039F4@xxxxxxxx.xxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Technical papers are solicited for presentation at the 29th Annual ARRL
and TAPR Digital Communications Conference to be held September 24-26,
2010 in Portland, Oregon. These papers will also be published in the
Conference Proceedings (you do NOT need to attend the conference to have
your paper included in the Proceedings). The submission deadline is July
31, 2010. Please send papers to:
Maty Weinberg
ARRL
225 Main St
Newington, CT 06111
or you can make your submission via e-mail to: maty@xxxx.xxx
Papers will be published exactly as submitted and authors will retain
all rights.
73 . . . Steve, WB8IMY
ARRL
------------------------------
Message: 16
Date: Wed, 12 May 2010 06:12:40 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] Tone on AO-51?
To: amsat-bb@xxxxx.xxx
Message-ID: <4BEA46D8.22546.23AC24@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
May 10 - May 16
FM Repeater, V/S
Uplink: 145.880 MHz FM
Downlink: 2401.200 MHz FM
67 Hz PL Tone Required
I work it without the PL tone this morning 0539 EDT pass. Is the tone is
present only when AO-51 is in eclipse?
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
DSTAR urcall VE2DWE
WAC BASIC CW PHONE SATELLITE
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 5, Issue 217
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