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CX2SA > SATDIG 07.10.10 09:14l 930 Lines 28423 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: LHCP or RHCP? (PA3GUO)
2. Re: SatPC32 Help Needed (David Palmer)
3. Re: SatPC32 Help Needed (Edward R. Cole)
4. Re: SatPC32 Help Needed (David Palmer)
5. Res: HO-68 FM audiostream via internet (Carlos Paoli)
6. S band (Jack Barbera)
7. Symposium Audio/Video Feed? (Joseph Armbruster)
8. Help required for KiwiSAT. (Terry Carrell)
9. Re: LHCP or RHCP? (i8cvs)
10. Re: LHCP or RHCP? (i8cvs)
11. Re Re: LHCP or RHCP? (i8cvs)
12. Re: LHCP or RHCP? (i8cvs)
13. Re: LHCP or RHCP? (Tom)
14. Re: LHCP or RHCP? (i8cvs)
15. AMSAT Awards (Bruce)
16. Re: LHCP or RHCP? (i8cvs)
17. Is AO-51 in PBBS mode? (Bruce Semple)
18. AMSAT Symposium This Weekend Near O'Hare Airport in Elk Grove
Village, IL (Mark Thompson)
----------------------------------------------------------------------
Message: 1
Date: Wed, 6 Oct 2010 21:25:11 +0200
From: PA3GUO <pa3guo@xxxxxxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: amsat-bb@xxxxx.xxx
Message-ID: <3041040.1286393111546.JavaMail.root@xxxxxxxx>
Content-Type: text/plain; charset=utf-8
Mak SV1BSX (SK) visualized it nicely here:
http://sv1bsx.50webs.com/antenna-pol/polarization.html
.. but best is to wait for Domenico to jump in :-)
(Domenico, one day you need to publish your excellent lectures on the
internet !)
--
Henk, PA3GUO
------------------------------
Message: 2
Date: Wed, 6 Oct 2010 12:35:34 -0700
From: David Palmer <dave@xxxx.xxx>
Subject: [amsat-bb] Re: SatPC32 Help Needed
To: Guy Brauning <guyjeanbraun@xxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<AANLkTi=uXYbz+hmE8fbXjxX0nunx1tbjh=_+T6Y4AduY@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi Guy and Amsat-List!
I'd like to know the answer to this too! I just recently started
using twin FT-817ND's and SatPC32 as well, and notice the exact same
thing -- audio drifts slightly thorughout the pass, even though I have
the dopper correction set pretty close. For me, it only drifts a few
hundred Hz at most, but it's still enough that I have to tweak the
offset on the uplink. I'm new to SSB sats so not sure as well if
there's something I'm doing wrong. I've got the time on the PC clock
set within 1 second, and my lat/long within 0.01 degrees.
I'm measuring the drift just roughly based on my own audio coming back
over the downlink -- unfortunately as I've called CQ on FO-29 and
VO-52 the last few evening's passes (0100-0500 UTC), no one else has
been on the sats for a direct QSO! My own audio comes back nice and
clear (even out to 5 degrees elevation) so it's not a reception
problem, as far as I know.
Any help for those of us new to the satellites would be appreciated!
Thanks,
Dave KB5WIA CM88 Northern California
2xFT817-ND, Elk Log-Periodic, MH-72 Duplexer, Samsung Netbook running SatPC32.
> Is anyone else using two Yaesu FT-817
> / 857 / 897 rigs with SatPC32? ?If so, what do you think I am doing wrong
> and what are your DOPPLER.SQF data lines for AO-7, VO-52, and FO-29 (as well
> as any other critical settings)?
------------------------------
Message: 3
Date: Wed, 06 Oct 2010 12:00:13 -0800
From: "Edward R. Cole" <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: SatPC32 Help Needed
To: David Palmer <dave@xxxx.xxx>, Guy Brauning
<guyjeanbraun@xxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <201010062000.o96K0D0R084178@xxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
David,
I'll step in here with a brief comment which you may already have considered:
Doppler frequency offset changes throughout a pass, so if you
transmit on a fixed frequency on the uplink, the downlink frequency
will change due both due to Doppler effects on the uplink and
downlink frequencies. If this is mode-UV the amount of Doppler will
be more on the uplink due to the higher frequency.
Another effect that many do not take into mind is that Doppler
changes at a non-linear rate; in other words it changes faster near
the point where Doppler goes from positive shift to negative shift in
the rest frequency of the satellite. I know it sounds like a lot of
math. But as an operator you just need only realize that this will
happen resulting in tuning the signal over the duration of the pass
(tune faster at mid-point of pass).
When one gets up to modes like LS, it gets more challenging because
both Doppler and rate of Doppler change are greater. Probably should
consider computer tuning of the radio at this point.
Note that Leo satellites go thru faster frequency change due to the
quicker pass overhead. Heo's taking hours for a pass require
retuning less often.
Others may provide more definitive help with your question.
73, Ed - KL7UW
At 11:35 AM 10/6/2010, David Palmer wrote:
>Hi Guy and Amsat-List!
>
>I'd like to know the answer to this too! I just recently started
>using twin FT-817ND's and SatPC32 as well, and notice the exact same
>thing -- audio drifts slightly thorughout the pass, even though I have
>the dopper correction set pretty close. For me, it only drifts a few
>hundred Hz at most, but it's still enough that I have to tweak the
>offset on the uplink. I'm new to SSB sats so not sure as well if
>there's something I'm doing wrong. I've got the time on the PC clock
>set within 1 second, and my lat/long within 0.01 degrees.
>
>I'm measuring the drift just roughly based on my own audio coming back
>over the downlink -- unfortunately as I've called CQ on FO-29 and
>VO-52 the last few evening's passes (0100-0500 UTC), no one else has
>been on the sats for a direct QSO! My own audio comes back nice and
>clear (even out to 5 degrees elevation) so it's not a reception
>problem, as far as I know.
>
>Any help for those of us new to the satellites would be appreciated!
>
>Thanks,
>
>Dave KB5WIA CM88 Northern California
>2xFT817-ND, Elk Log-Periodic, MH-72 Duplexer, Samsung Netbook running
SatPC32.
>
> > Is anyone else using two Yaesu FT-817
> > / 857 / 897 rigs with SatPC32? If so, what do you think I am doing wrong
> > and what are your DOPPLER.SQF data lines for AO-7, VO-52, and
> FO-29 (as well
> > as any other critical settings)?
>
>_______________________________________________
>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
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-QRT*, 432-100w, 1296-QRT*, 3400-winter?
DUBUS Magazine USA Rep dubususa@xxxxxxx.xxx
======================================
*temp
------------------------------
Message: 4
Date: Wed, 6 Oct 2010 13:11:50 -0700
From: David Palmer <dave@xxxx.xxx>
Subject: [amsat-bb] Re: SatPC32 Help Needed
To: "Edward R. Cole" <kl7uw@xxxxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx Guy Brauning <guyjeanbraun@xxxxxxx.xxx>
Message-ID:
<AANLkTik-qMb1Q4MLgh9Y81eoQh91mMNm7eQawCiJ+4wD@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi Ed,
Thanks for the fast response! Yeah, both the original poster (Guy)
and myself are using computer tuning of both radios. I know for sure
my SatPC32 is set up for adjusting both the uplink and the downlink,
and I see the readout on the radio changing accordingly, so it seems
to be working ... what puzzles me is why the computer tuning seems to
be so poor, since even though it's complex math, it's just math and
the computer should be able to keep up!
Of course, since there are many on the list here using SatPC32 and
twin radios successfully, I'm almost certain it's operator error
that's causing this slight drift (or lack of complete correction), but
I just can't figure out what it is yet. :-)
One thing I *did* notice with the Twin FT-817's, is that those radios
(817,857, 897) do not update the TX frequency by CAT while they're
transmitting ... so as I call CQ, I definitely hear my voice drop in
pitch because the SatPC32 is busy updating the downlink frequency but
the radio is busy so is not updating the uplink frequency. I accept
that as normal (and just unkey to let the computer reset the radio for
proper shift) but ...
... what's confusing me is that the amount of correction seems to
change from pass to pass and even during the pass ... at first (out of
the box) SatPC32 was about 2400 Hz low on the uplink based on the
values in the doppler.sqf file. I just figured it could be due to
radio calibration, etc, so I applied the calibration factor, and now
it's much closer ... but still I seem to have to adjust +/- 100 to 200
Hz at the start of the pass, and periodically during the pass, to keep
my return pitch constant.
Thanks everyone!
Dave KB5WIA CM88 Northern California.
> When one gets up to modes like LS, it gets more challenging because both
> Doppler and rate of Doppler change are greater. ?Probably should consider
> computer tuning of the radio at this point.
------------------------------
Message: 5
Date: Wed, 6 Oct 2010 13:20:20 -0700 (PDT)
From: Carlos Paoli <crpaoli@xxxxx.xxx.xx>
Subject: [amsat-bb] Res: HO-68 FM audiostream via internet
To: amsat-bb@xxxxx.xxx
Message-ID: <152216.30195.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Hi Henk,
I'm listening now several stations of Europe and a little packet radio too.
It's pretty cool because I have packed my equipment since I changed my QTH.
Very good job!
73, Carlos Paoli - PY2FFZ
________________________________
De: PA3GUO <pa3guo@xxxxxxx.xx>
Para: amsat-bb@xxxxx.xxx
Enviadas: Quarta-feira, 6 de Outubro de 2010 15:02:07
Assunto: [amsat-bb] HO-68 FM audiostream via internet
HO-68 is in FM mode, I will put a live audiostream this evening at:
http://www.pa3guo.com/webradio.html
There is approx. a 12 seconds delay.
18:10...Turn On--FM/PACSAT
Africa,Middle East,Europe,NA
18:55...Turn Off
19:35...Turn On--FM/PACSAT
Africa,Middle East,Europe,NA
20:20...Turn Off
Depending on the interest I may leave it on also the next days.
Henk, PA3GUO
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 6
Date: Wed, 6 Oct 2010 14:02:53 -0700 (PDT)
From: Jack Barbera <barberaalderwood@xxxxx.xxx>
Subject: [amsat-bb] S band
To: Amsat Reflector <amsat-bb@xxxxx.xxx>
Message-ID: <326201.86341.qm@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Need a little help.
First I'd like to thank everyone for your answers to my question concerning
ISS
beacon.
I am all set to add L band to my station using my IC910 including Rohn 25
folder
over tower to be mounted to the side of my house.? While I'm at it I wonder if
it would make sense to add S band as well, if so, should I add transmitting as
well as?receiving capabilitie?? Should I use a two meter or a 70 cm radio
knowing that two meter would provide?less loss?? Any thoughts on this would be
appreciated & most likley I will have further questions as I get into this
project.?
Thanks for any input.?Jack WA1ZDV
------------------------------
Message: 7
Date: Wed, 6 Oct 2010 17:06:23 -0400
From: Joseph Armbruster <josepharmbruster@xxxxx.xxx>
Subject: [amsat-bb] Symposium Audio/Video Feed?
To: amsat-bb@xxxxx.xxx
Message-ID:
<AANLkTinfjaCd+ZPE1qobcQ9sC=EHoxeLBivadDK8s-P-@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Attn: Symposium Coordinators
Will there be an audio or video feed coming from the symposium this year?
Unfortunately, I am unable to attend in person this year. However, I would
love to tune in to hear the latest news and what is planned for the future.
Thank you!
Joseph Armbruster
------------------------------
Message: 8
Date: Thu, 7 Oct 2010 10:11:45 +1300
From: "Terry Carrell" <tcarrell@xxxx.xx.xx>
Subject: [amsat-bb] Help required for KiwiSAT.
To: "Amsat-bb" <amsat-bb@xxxxx.xxx>
Message-ID: <71ED68BDD981446B9788DCC267367B0D@xxxxxxxx>
Content-Type: text/plain; charset="Windows-1252"
>From the KiwiSAT team.
Can you help us?
We require four (4) Cypress CY7C383A-0JC or QuickLogic QL12x16-2PL68C FPGA
chips, used & un-programmed.
To date we have had 2 lots of 4 from two different sources but all proved to
have been compromised and could not be programmed. We had a small stock but
they have all been used during our development work and while we can
purchase new units, the source requires us to buy a significant number more
than our requirement which is proving to be very expensive.
We are happy to pay for good units once we have confirmed they are clean. A
matter of twice bitten, thrice shy.
These chips will fly so it is important we have perfect units.
If you help in any way, please let me know.
Terry, ZL3QL. ? AMSAT-ZL
------------------------------
Message: 9
Date: Wed, 6 Oct 2010 23:29:43 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <k0tw@xxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <001501cb659d$97f3cfc0$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Tom, K0TW
In a separate email I have sent to you what in my opinion is the best and
easy to understand article about the use of circular polarization written
by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
----- Original Message -----
From: "Tom" <k0tw@xxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, October 06, 2010 1:23 AM
Subject: [amsat-bb] LHCP or RHCP?
> On the premise that the only dumb question is the one that goes unasked,
> here goes.
>
> If I'm building an antenna of circular polarization for use with the birds
> what determines if it should be LHCP or RHCP? I've read the ARRL Satellite
> Handbook and "sort of" searched the AMSAT-BB archives but found nothing
> about this question.
>
> Thanks.
> Tom - K0TW
> _______________________________________________
> 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: 10
Date: Wed, 6 Oct 2010 23:54:40 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <pa3guo@xxxxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <002d01cb65a1$142992c0$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Tom, K0TW
In a separate email I have sent to you what in my opinion is the best and
easy to understand article about the use of circular polarization written
by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
73" de
i8CVS Domenico
----- Original Message -----
From: "PA3GUO" <pa3guo@xxxxxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, October 06, 2010 9:25 PM
Subject: [amsat-bb] Re: LHCP or RHCP?
> Mak SV1BSX (SK) visualized it nicely here:
> http://sv1bsx.50webs.com/antenna-pol/polarization.html
>
> .. but best is to wait for Domenico to jump in :-)
> (Domenico, one day you need to publish your excellent lectures on the
internet !)
>
> --
> Henk, PA3GUO
>
> _______________________________________________
> 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: Thu, 7 Oct 2010 00:02:58 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re Re: LHCP or RHCP?
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>, <pa3guo@xxxxx.xxx>
Message-ID: <003101cb65a2$3ccd83c0$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Henk PA3GUO
In a separate email I have sent to you what in my opinion is the best and
easy to understand article about the use of circular polarization written
by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
----- Original Message -----
From: "PA3GUO" <pa3guo@xxxxxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, October 06, 2010 9:25 PM
Subject: [amsat-bb] Re: LHCP or RHCP?
Mak SV1BSX (SK) visualized it nicely here:
http://sv1bsx.50webs.com/antenna-pol/polarization.html
.. but best is to wait for Domenico to jump in :-)
(Domenico, one day you need to publish your excellent lectures on the
internet !)
--
Henk, PA3GUO
------------------------------
Message: 12
Date: Wed, 6 Oct 2010 23:18:40 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <k0tw@xxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <000001cb659c$504e3f80$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Tom, K0TW
In a separate email I have sent to you what in my opinion is the best and
easy to understand article about the use of circular polarization written
by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
----- Original Message -----
From: "Tom" <k0tw@xxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, October 06, 2010 1:23 AM
Subject: [amsat-bb] LHCP or RHCP?
> On the premise that the only dumb question is the one that goes unasked,
> here goes.
>
> If I'm building an antenna of circular polarization for use with the birds
> what determines if it should be LHCP or RHCP? I've read the ARRL Satellite
> Handbook and "sort of" searched the AMSAT-BB archives but found nothing
> about this question.
>
> Thanks.
> Tom - K0TW
> _______________________________________________
> 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: 13
Date: Wed, 6 Oct 2010 15:42:57 -0700
From: "Tom" <k0tw@xxx.xxx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <amsat-bb@xxxxx.xxx>
Message-ID: <09B4D7B0D6B04B72956237ECE3CC6D7E@xxxxxxxx>
Content-Type: text/plain; charset="us-ascii"
Perhaps I should have worded my question differently. I understand the
concept of circular polarization and the reasons for it. What I should have
asked was "Is one direction preferred over the other for working the
satellites?". Thanks for all the excellent info and I think what I've
learned is that the ability to switch between directions of polarization is
best but RHCP is preferred if only one direction is available.
Domenico, thanks for the attachments. Good stuff which I had not seen
before!
Tom - K0TW
> If I'm building an antenna of circular polarization for use with the birds
> what determines if it should be LHCP or RHCP? I've read the ARRL Satellite
> Handbook and "sort of" searched the AMSAT-BB archives but found nothing
> about this question.
>
>Thanks.
>Tom - K0TW
------------------------------
Message: 14
Date: Thu, 7 Oct 2010 00:44:14 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <pa3guo@xxxxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <001e01cb65a8$00ac6400$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "PA3GUO" <pa3guo@xxxxxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Sent: Wednesday, October 06, 2010 9:25 PM
Subject: [amsat-bb] Re: LHCP or RHCP?
> Mak SV1BSX (SK) visualized it nicely here:
> http://sv1bsx.50webs.com/antenna-pol/polarization.html
>
> .. but best is to wait for Domenico to jump in :-)
> (Domenico, one day you need to publish your excellent lectures on the
internet !)
>
> --
> Henk, PA3GUO
>
Hi Henk, PA3GUO
The Mak article SV1BSK (SK) is a very good article indeed about circular
polarizatrion.
Unfortunately our good friend MAK died too young at the beginning of
this year.
In my opinion there is a mistake in the last two drawing of the article
where he is depicting two crossed yagi.
The green dotted line as seen from the reflector is really showing a CCW
polarization and the red dotted line of the last drawing as seen from the
reflector is really showing a CW polarization.
http://sv1bsx.50webs.com/antenna-pol/polarization.html
This is only my optical opinion or my optical illusion ?
I would like to know your comment about because the sense of
polarizations CW and CCW as marked by MAK seems to me to
be reversed.
I recognized it only this evening.
Best 73" de
i8CVS Domenico
------------------------------
Message: 15
Date: Wed, 06 Oct 2010 18:11:56 -0500
From: Bruce <kk5do@xxxxx.xxx>
Subject: [amsat-bb] AMSAT Awards
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Message-ID: <4CAD023C.4010600@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Here are the awards that I have processed over the last month or so.
The following have entered into the Satellite Communicators Club for
making their first satellite QSO.
Jay Kendall, N2JK
Darek Dabek, SP9TTX
Marisuz Kocot, SQ9MES
The following have earned the AMSAT Communications Achievement Award.
Bob Herrell, AJ5C #517
Jim Adams, K0BAM #518
Leo Hucin, OK2UUJ #519
Jay Kendall, N2JK #520
The following have earned the South Africa AMSAT Communications
Achievement Award
Jim Adams, K0BAM #US149
Jay Kendall, N2JK #US150
Marisuz Kocot, SQ9MES #US151
The following have earned the AMSAT Century Club Award
John Papay, K8YSE #39
The following have earned the W4AMI Satellite Communications Achievement
award
Bob Herrell, AJ5C, #64
Zachary Beougher, KD8KSN #65
Mariusz Kocot, SQ9MES, #66 (plus 1 endorsement)
Darek Dabek, SP9TTX, #67 (plus 3 endorsements)
The following have earned the W4AMI 5000 Satellite Communications
Achievement award
Darek Dabek, SP9TTX #24
To see all the awards visit http://www.amsat.org or
http://www.amsatnet.com
Bruce Paige, KK5DO
AMSAT Director Contests and Awards
ARRL Awards Manager (WAS, 5BWAS, VUCC), VE
Houston AMSAT Net - Wed 0100z on Echolink - Conference *AMSAT*
Also streaming MP3 at http://www.amsatnet.com
Podcast at http://www.amsatnet.com/podcast.xml or iTunes
------------------------------
Message: 16
Date: Thu, 7 Oct 2010 02:42:55 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: LHCP or RHCP?
To: <k0tw@xxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <000701cb65b8$9555b100$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Tom, K0TW
If a satellite transmit RHCP and your antenna is LHCP then you loose almost
20 db on receiving !
As an example VO-52 transmit LHCP on 2 meters toward the ground and if
your antenna is only RHCP polarized your received signal will be very weak.
In addition during the orbit the satellite is tumbling and the sense of
polarization changes many time between RHCP to LHCP during an orbit.
More over the sense of polarization changes by the Faraday rotation as the
wave passes through the ionospefere.
This is why switching between RHCP to LHCP on receiving and transmitting
is strongly recommended particularly using LEO satellites that are not three
axis stabilized and the antennas are not constantly pointed toward the
earth.
By the way if you use linear polarization on receiving in any condition you
will loose a maximum of 3 dB suffering more fading instead of loosing about
20 dB using the wrong or reversed circular polarization.
73" de
i8CVS Domenico.
----- Original Message -----
From: "Tom" <k0tw@xxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Sent: Thursday, October 07, 2010 12:42 AM
Subject: [amsat-bb] Re: LHCP or RHCP?
>
> Perhaps I should have worded my question differently. I understand the
> concept of circular polarization and the reasons for it. What I should
have
> asked was "Is one direction preferred over the other for working the
> satellites?". Thanks for all the excellent info and I think what I've
> learned is that the ability to switch between directions of polarization
is
> best but RHCP is preferred if only one direction is available.
>
> Domenico, thanks for the attachments. Good stuff which I had not seen
> before!
>
> Tom - K0TW
>
> > If I'm building an antenna of circular polarization for use with the
birds
> > what determines if it should be LHCP or RHCP? I've read the ARRL
Satellite
> > Handbook and "sort of" searched the AMSAT-BB archives but found nothing
> > about this question.
> >
> >Thanks.
> >Tom - K0TW
>
>
>
> _______________________________________________
> 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: 17
Date: Wed, 06 Oct 2010 21:20:29 -0400
From: Bruce Semple <bruce.semple@xxxxxxx.xxx>
Subject: [amsat-bb] Is AO-51 in PBBS mode?
To: amsat-bb@xxxxx.xxx
Message-ID: <0L9W008P9BQ63M50@xxxxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii; format=flowed
I see that the schedule calls for it to be in PBBS mode -- but is it really?
I was seeing all the telemetry frames --
but no PECHO-11, PECHO-12 ..
Bruce
WA3SWJ
------------------------------
Message: 18
Date: Wed, 6 Oct 2010 23:50:14 -0700 (PDT)
From: Mark Thompson <wb9qzb_groups@xxxxx.xxx>
Subject: [amsat-bb] AMSAT Symposium This Weekend Near O'Hare Airport
in Elk Grove Village, IL
To: amsat-bb@xxxxx.xxxx NS9RC@xxxxxxxxxxx.xxxx frrl@xxxxxxxxxxx.xxxx
WeLCARS@xxxxxxxxxxx.xxxx PeoriaARC@xxxxxxxxxxx.xxxx
svrc@xxxxxxxxxxx.xxxx chicagoamateurradio@xxxxxxxxxxx.xxxx
MadisonAmateurRadio@xxxxxxxxxxx.xxxx
amateurradiomilwaukee@xxxxxxxxxxx.xxxx IndyHamRadio@xxxxxxxxxxx.xxxx
CentralIndianaHams@xxxxxxxxxxx.xxxx westmichiganhams@xxxxxxxxxxx.xxxx
IllinoisPacketRadio@xxxxxxxxxxx.xxxx IN_PACKET@xxxxxxxxxxx.xxx
Cc: uco@xxxx.xxx
Message-ID: <259799.34003.qm@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Note: More information about the symposium in attached files & at
www.amsat.org/amsat-new/2010/index.php
Date: Sun, 3 Oct 2010 22:07:40 GMT
From: "uco@xxxx.xxxx <uco@xxxx.xxx>
Subject: MAMSAT SYMPOSIUM THIS WEEK - CHICAGO
To:
ARISSat-1 will be the presented in detail during the Saturday morning
sessions
at the AMSAT 2010 Space Symposium and Annual Meeting which will be held on
Friday, October 8 through Sunday, October 10.
AMSAT Vice-President of Engineering Tony Montiero, AA2TX and ARISSat Project
Manager Gould Smith, WA4SXM along with ARISSat team members will host the
Saturday ARRISat-1 sessions including:
* ARISSat-1 Overview
* Software Radio Technology
* BPSK-1000 format for ARISSat-1
* ARISSatTLM - Software Demodulator and Telemetry Program
* Calculating Available Power (Examples: ARISSat & Fox)
* Power System
* Assembling ARISSat-1
* ARISSat-1 Vibration Testing
The team plans to have a working ARISSat-1 prototype attending the Symposium.
ARISSat-1 design and operations are discussed in detail in these papers
published in the 2010 Symposium Proceedings book:
* ARISSat-1 Overview by Tony Monteiro AA2TX
* ARISSat-1 Power System by Tony Monteiro AA2TX
* Software Radio Technology on ARISSat-1 by Tony Montiero AA2TX
* ARISSatTLM - A Software Demodulator and Telemetry Display Program for
the
ARISSat-1 Satellite by Douglas Quagliana KA2UPW
* BPSK-1000 format for ARISSat-1 by Phil Karn KA9Q
An additional feature presentation and paper will introduce you to AMSAT's
next satellite ... AMSAT-FOX Preview by Tony Monteiro, AA2TX.
The AMSAT 2010 Space Symposium and Annual General Meeting will be held at the
Chicago/Elk Grove Holiday Inn which is near O'Hare Airport.
On-line registration for the Symposium continues on-line at the AMSAT Store.
The registration fee is $45.00 from now through 5 October. Online
registration
closes 5 October at Midnight. Registration at the door will be $50.00.
73,
John - AG9D
Symposium Host Committee
------------------------------
_______________________________________________
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 404
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