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CX2SA > SATDIG 20.03.18 18:00l 1339 Lines 49569 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: Antenna Polarization Question (Jordan Trewitt)
2. Re: weekly nets / live chat ? (davekn4ok@???.????
3. Upcoming ARISS Contact Schedule as of 2018-03-20 03:00 UTC
(aj9n@???.????
4. Re: Antenna Polarization Question (Wendy and Terry Osborne)
5. Upcoming ARISS Contact Schedule as of 2018-03-20 05:30 UTC
(aj9n@???.????
6. Re: Antenna Polarization Question (Franklin Antonio)
----------------------------------------------------------------------
Message: 1
Date: Mon, 19 Mar 2018 19:12:34 +0000
From: Jordan Trewitt <jmtrewitt@?????.???>
To: Jean Marc Momple <jean.marc.momple@?????.???>
Cc: "amsat-bb@?????.???? <amsat-bb@?????.???>, Burns Fisher
<burns@??????.??>
Subject: Re: [amsat-bb] Antenna Polarization Question
Message-ID:
<CAHD9BgC7BnZZ_Akxwt1kPXHD6+Kq2xNNrOq6MvrfY5ictzuhYQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
I'll say, why not both? I need to get to trying out my cross-pole yagi with
my LimeSDR, which should be able to receive two inputs at the same time.
>From there I'm assuming I could just set up some phase delays in GNU Radio
and adders to produce both LHCP and RHCP at the same time, in theory at
least. Only problem is that I've heard there's some inconsistent phase
differences between the two channels.
-Jordan
KF5COQ
On Mon, Mar 19, 2018 at 2:03 PM Jean Marc Momple <jean.marc.momple@?????.???>
wrote:
> Try it!
>
> Then it would be clearer to you, practice is just an extension of theory
> (or vice-versa). Hi!
>
> In our case there many unknown variable that there is no ?thumb rule?, it
> depends obviously on what the birds are doing up there.
>
> 73
>
> Jean Marc (3B8DU)
>
>
>
> > On Mar 19, 2018, at 10:33 PM, Burns Fisher <burns@??????.??> wrote:
> >
> > I'd really like to understand this better, but it is still not making
> sense to me. I believe that if you are transmitting with a CP antenna, the
> E and M waves actually go through an entire circle in one carrier cycle and
> a CP antenna is able to "follow" that. Surely a satellite is not spinning
> at anywhere close to 145 or 450 million revs per second, so I don't get
> "spinning satellite" as an explanation for why an LHP or RHP antenna might
> work better at different times.
> >
> > What I do get is that a CP antenna can receive linearly polarized waves
> at any angle equally. But this should be true whether the antenna is LHP
> or RHP, and I would not think which direction should matter if the signal
> is linear in the first place, even if the signal is spinning slowly.
> >
> > That all said, I have definitely heard people say that they can get
> better reception by changing from LHP to RHP. I'm not saying this is not
> true. Just that I don't understand it.
> >
> > 73,
> >
> > Burns WB1FJ
> >
> > On Mon, Mar 19, 2018 at 1:57 PM, Jean Marc Momple <
> jean.marc.momple@?????.??? <mailto:jean.marc.momple@?????.???>> wrote:
> > Guys,
> >
> > Long debate for not much. I have followed this stream and believe that I
> need to intervene.
> >
> > It is very simple, most HAM birds does spin (sometimes a lot) and there
> is no way one can anticipate as different from one bird to others. It is
> just operator skills (on the spot) to determine/switch from LHCP or RCCP
> based on what is the best received signal strength. It works both on the
> Uplink and Downlink. There is no miracle formulae and it is a just operator
> skills as mentioned before.
> >
> > For commercial birds it is totally different game and should not be
> compared with our humble Ham birds, they have much more means to do things
> that we cannot afford to do, except if all HAM worldwide donate to AMSAT,
> say $10 we then may be able to match some of the features commercially
> available.
> >
> > Just a suggestion and food for thought.
> >
> >
> > 73
> >
> >
> > Jean Marc (3B8DU)
> >
> >
> > > On Mar 19, 2018, at 8:54 PM, Franklin Antonio <
> antonio@???.????????.??? <mailto:antonio@???.????????.???>> wrote:
> > >
> > > When you say a satellite "has" RHCP, we have to be careful that we're
> communicating clearly about what "has" means. Every satellite "has" both,
> by virtue of he way antennas work.
> > >
> > > I suspect that you mean that the satellite has an antenna which
> transmits RHCP in its main lobe. It is important to realize that the
> signal from such an antenna is only RHCP in its main lobe. The sidelobes
> are gonna be LHCP. In between, you can get anything in between. So if a
> satellite is oriented so that its antenna points right at you, and they
> designed it to be RHCP, then that's what you're gonna get, but if it is
> pointing off to the side, then you get something else.
> > >
> > > This means that there are situations in which you might get a stronger
> received signal if you switch to LHCP, or maybe even to linear. In the
> commercial satellite biz, they design satellites so that their antennas
> point at the users. Hams build cheaper satellites, which typically don't
> have sophisticated attitude control, so sometimes they point away from
> you. Also, hams try to use the things even when conditions aren't the
> best. If that's your aim, then most folks have found that polarization
> switching sometimes helps.
> > >
> > > ________________________________________
> > > From: AMSAT-BB <amsat-bb-bounces@?????.??? <mailto:
> amsat-bb-bounces@?????.???>> on behalf of Jordan Trewitt <
> jmtrewitt@?????.??? <mailto:jmtrewitt@?????.???>>
> > > Sent: Sunday, March 18, 2018 2:43 PM
> > > To: Eduardo PY2RN
> > > Cc: amsat-bb@?????.??? <mailto:amsat-bb@?????.???>
> > > Subject: Re: [amsat-bb] Antenna Polarization Question
> > >
> > > Maybe I'm not understanding it, but why does one need to switch between
> > > both, unless a particular satellite has LHCP or RHCP?
> > > Jordan
> > > KF5COQ
> > >
> > > On Sun, Mar 18, 2018, 16:34 Eduardo PY2RN <py2rn@????.??? <mailto:
> py2rn@????.???>> wrote:
> > >
> > >> Hi Brian,
> > >> Both. You are going to need to switch between RHCP and LHCP often
> during a
> > >> sat pass. The same happens if using linear polarization (V/H) but in
> this
> > >> case the switch between V and H will happen much more often than in
> CP.
> > >> 73
> > >> Ed
> > >> PY2RN
> > >>
> > >> From: Brian via AMSAT-BB <amsat-bb@?????.??? <mailto:
> amsat-bb@?????.???>>
> > >> To: "amsat-bb@?????.??? <mailto:amsat-bb@?????.???>" <
> amsat-bb@?????.??? <mailto:amsat-bb@?????.???>>
> > >> Sent: Sunday, March 18, 2018 6:21 PM
> > >> Subject: [amsat-bb] Antenna Polarization Question
> > >>
> > >>
> > >>
> > >> Should I be using LHCP or RHCP when setting up the 2 meter and 440
> yagi's
> > >> to work the LEO's.
> > >>
> > >> Thank you
> > >>
> > >> Brian, KG8CO
> > >>
> > >> _______________________________________________
> > >> Sent via AMSAT-BB@?????.??? <mailto:AMSAT-BB@?????.???>. AMSAT-NA
> makes this open forum available
> > >> to all interested persons worldwide without requiring membership.
> Opinions
> > >> expressed
> > >> are solely those of the author, and do not reflect the official views
> of
> > >> AMSAT-NA.
> > >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> <http://www.amsat.org/mailman/listinfo/amsat-bb>
> > >>
> > >>
> > >>
> > >> _______________________________________________
> > >> Sent via AMSAT-BB@?????.??? <mailto:AMSAT-BB@?????.???>. AMSAT-NA
> makes this open forum available
> > >> to all interested persons worldwide without requiring membership.
> Opinions
> > >> expressed
> > >> are solely those of the author, and do not reflect the official views
> of
> > >> AMSAT-NA.
> > >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> <http://www.amsat.org/mailman/listinfo/amsat-bb>
> > >>
> > > _______________________________________________
> > > Sent via AMSAT-BB@?????.??? <mailto:AMSAT-BB@?????.???>. AMSAT-NA
> makes this open forum available
> > > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > > are solely those of the author, and do not reflect the official views
> of AMSAT-NA.
> > > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> <http://www.amsat.org/mailman/listinfo/amsat-bb>
> > > _______________________________________________
> > > Sent via AMSAT-BB@?????.??? <mailto:AMSAT-BB@?????.???>. AMSAT-NA
> makes this open forum available
> > > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > > are solely those of the author, and do not reflect the official views
> of AMSAT-NA.
> > > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> <http://www.amsat.org/mailman/listinfo/amsat-bb>
> >
> > _______________________________________________
> > Sent via AMSAT-BB@?????.??? <mailto:AMSAT-BB@?????.???>. AMSAT-NA makes
> this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb <
> http://www.amsat.org/mailman/listinfo/amsat-bb>
> >
>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 2
Date: Mon, 19 Mar 2018 17:00:09 -0400
From: davekn4ok@???.???
To: amsat-bb@?????.???
Subject: Re: [amsat-bb] weekly nets / live chat ?
Message-ID: <162400fe76f-179e-9c83@?????????????.???.???????.???>
Content-Type: text/plain; charset=utf-8
You can always meet with satellite ops here:
http://n8fq.org/sked/index.php?board=sat
-----Original Message-----
From: Graham <planophore@???.??>
To: amsat-bb <amsat-bb@?????.???>
Sent: Mon, Mar 19, 2018 3:56 pm
Subject: Re: [amsat-bb] weekly nets / live chat ?
Something like Ping Jockey but for the satellites is an excellent idea; I
would use it and would likely be more active because of it.cheers, Graham
ve3gtc FN25igOn 2018-03-19 16:57, Mr B r a d via AMSAT-BB wrote:>
-=-=-=-=-=-=-=-=-=-> """ Patrick WD9EWK/VA7EWK" .....from the last dispatch
of messages ....Re: trying to get back to the Sunday evening AMSAT
roundtable """"> I Guess that is on d-star ?? this would be great to listen
in on from a new Op perspective .....> I have been looking for a Sat IRC or
Sat-Op chat room or something like "ping jockey" toget get some quick
answers to operating questions and line up some QSO's and have not found
anything for this. even a HF or echo-link net could be helpful.this could
also solve the ' no one else was on the bird' problem.> sticking my neck out
here , but I could host it on my valleymedia.org domain withone of the free
chat room scripts if nothing more official or better is out here or
offered?> one link on the 'easy sats' / work-sa
ts page would fuel the live sat-chat room very nicely>> new guy Ko6kLBrad>
-=-=-=-=-=-=-=-=-=-=->>>>> >>>>>>
_______________________________________________> Sent via
AMSAT-BB@?????.???. AMSAT-NA makes this open forum available> to all
interested persons worldwide without requiring membership. Opinions
expressed> are solely those of the author, and do not reflect the official
views of AMSAT-NA.> Not an AMSAT-NA member? Join now to support the amateur
satellite program!> Subscription settings:
http://www.amsat.org/mailman/listinfo/amsat-bb________________________________
_______________Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum
availableto all interested persons worldwide without requiring membership.
Opinions expressedare solely those of the author, and do not reflect the
official views of AMSAT-NA.Not an AMSAT-NA member? Join now to support the
amateur satellite program!Subscription settings:
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 3
Date: Mon, 19 Mar 2018 22:04:47 -0400
From: aj9n@???.???
To: amsat-bb@?????.???
Subject: [amsat-bb] Upcoming ARISS Contact Schedule as of 2018-03-20
03:00 UTC
Message-ID: <1624126d78a-c87-326@?????????????.???.???????.???>
Content-Type: text/plain; charset=utf-8
Upcoming ARISS Contact Schedule as of 2018-03-20 03:00 UTC
Quick list of scheduled contacts and events:
?
Templestowe Valley Primary School, Templestowe, Victoria, Australia,
telebridge via VK4KHZ
The ISS callsign is presently scheduled to be NA1SS
The scheduled astronaut is Scott Tingle KG5NZA
Contact was successful: Mon 2018-03-19 08:43:46 UTC 27 deg (***)
?
Watch for live stream on the EchoLink AMSAT conference server live.??
******************************************************************************
International Space Station Astronauts are Calling CQ Students? (corrected)?
(***)
????????????? ?ARISS-US program education proposal deadline is April 30, 2018
?
March 15, 2018:? The Amateur Radio on the International Space Station
(ARISS) program is seeking proposals from US schools, museums, science
centers and community youth organizations (working individually or together)
to host radio contacts with an orbiting crew member aboard the International
Space Station (ISS) between January 1 and June 30, 2019.
?
Each year, ARISS provides tens of thousands of students with opportunities
to learn about space technologies and communications through the exploration
of Amateur Radio. ?The program provides learning opportunities by connecting
students to astronauts aboard the International Space Station (ISS) through
a partnership between NASA, the Radio Amateur Satellite Corporation, the
American Radio Relay League, and other Amateur Radio organizations and
worldwide space agencies. The program?s goal is to inspire students to
pursue interests and careers in science, technology, engineering and
mathematics (STEM) and Amateur Radio. A ham recently said, ?ARISS shows how
Amateur Radio is the most unique hobby/service there is.?
?
Educators overwhelmingly report that student participation in the ARISS
program stimulates interest in STEM subjects and in STEM careers. One
educator wrote, ?It exceeded our expectations--it created a great interest
in both amateur radio and in space exploration. Our kids are completely
inspired!? Ninety-two percent of educators who have participated in the
program have indicated that ARISS provided ideas for encouraging student
exploration and participation. An educator even joined the ham ranks,
saying, ?This chance for our school?s ARISS contact helped me see the great
value of the ham world.? I just passed my Technician License this weekend
and have already signed up to take a General class.?? ?
ARISS is looking for organizations that will draw large numbers of
participants and integrate the contact into a well-developed, exciting
education plan. Students can learn about satellite communications, wireless
technology, science research conducted on the ISS, radio science, and any
related STEM subject. Students learn to use Amateur Radio to talk directly
to an astronaut and ask their STEM-related questions. ARISS will help
educational organizations locate Amateur Radio groups who can assist with
equipment for this once-in-a-lifetime opportunity for students.
The proposal deadline for 2019 contacts is April 30, 2018. Proposal webinars
for guidance and getting questions answers will be offered March 29, 2018,
at 7 p.m. EDT and April 16, 2018, at 4 p.m. EDT. Advance registration is
necessary. To sign up, go to
https://ariss-proposal-webinar-spring-2018.eventbrite.com
For more details such as expectations, proposal guidelines and the proposal
form, visit: http://www.ariss.org/hosting-an-ariss-contact-in-the-us.html
?
******************************************************************************
ARISS is always glad to receive listener reports for the above contacts.?
ARISS thanks everyone in advance for their assistance.? Feel free to send
your reports to aj9n@?????.??? or aj9n@???.???.
?
Listen for the ISS on the downlink of 145.8? MHz.
?
******************************************************************************
*
?
All ARISS contacts are made via the Kenwood radio unless otherwise noted.
?
******************************************************************************
*
Several?of you have sent me emails asking about the RAC ARISS website and
not being able?to get in.? That has now been changed to?
http://www.ariss.org/
Note that there are links to other ARISS websites from this?site.
****************************************************************************
Looking?for something new to do?? How about receiving DATV from the ISS???
If interested, then please go to the ARISS-EU website for complete?
details.? Look for the buttons indicating Ham?Video.? ? ? ? ? ? ? ? ? ? ? ?
? ?
? ? ? ? ? ? ? ? ? ? ?
http://www.ariss-eu.org/? ?
?
If you need some assistance, ARISS mentor Kerry N6IZW, might be able to
provide some insight.? Contact Kerry at kbanke@?????????.???
****************************************************************************
ARISS congratulations the following mentors who have now mentored over 100
schools:?
Francesco IK?WGF with 132
Satoshi 7M3TJZ with 128
Gaston ON4WF with 123
Sergey RV3DR with 102
****************************************************************************
The?webpages listed below were all reviewed for accuracy.? Out of date
webpages?were removed and new ones have been added.? If there are additional
ARISS?websites I need to know about, please let me know.
Note, all times?are approximate.? It is recommended that you do your own
orbital prediction?or start listening about 10 minutes before the listed
time.
All dates and?times listed follow International Standard ISO 8601 date and
time format? YYYY-MM-DD HH:MM:SS
The complete schedule page has been updated as of?2018-03-20 03:00 UTC.? (***)
Here you will find a listing of all scheduled?school contacts, and
questions, other ISS related websites, IRLP and?Echolink websites, and
instructions for any contact that may be streamed?live.??
http://www.amsat.org/amsat/ariss/news/arissnews.rtf
http://www.amsat.org/amsat/ariss/news/arissnews.txt
Total number?of ARISS ISS to earth school events is 1216. (***)
Each school counts as 1?event.
Total number of ARISS ISS to earth school contacts is 1165. (***)
Each contact may have multiple schools sharing the same time slot.
Total number of ARISS supported terrestrial contacts is?47.
A complete year by year breakdown of the contacts may be found in the
file.
http://www.amsat.org/amsat/ariss/news/arissnews.rtf
Please?feel free to contact me if more detailed statistics are needed.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The?following US states and entities have never had an ARISS contact:
Arkansas,?Delaware, South Dakota, Wyoming, American?Samoa, Guam, Northern
Marianas Islands, and the Virgin Islands.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
QSL?information may be found at:??
http://www.ariss.org/qsl-cards.html?
ISS callsigns:? DP?ISS, IR?ISS, NA1SS, OR4ISS,?RS?ISS
****************************************************************************
The successful school list has been updated as of 2018-03-20 03:00 UTC.
http://www.amsat.org/amsat/ariss/news/Successful_ARISS_schools.rtf
Frequency? chart for packet, voice, and crossband repeater modes showing
Doppler? correction? as of 2005-07-29 04:00 UTC
http://www.amsat.org/amsat/ariss/news/ISS_frequencies_and_Doppler_correction
.rtf
Listing?of ARISS related magazine articles as of 2006-07-10 03:30 UTC.
http://www.amsat.org/amsat/ariss/news/ARISS_magazine_articles.rtf
Check out the Zoho reports of the ARISS?contacts
https://reports.zoho.com/ZDBDataSheetView.cc?DBID=412218000000020415
****************************************************************************
Exp. 54 on orbit
Scott Tingle KG5NZA
Norishige Kanai
Alexander Skvortsov
****************************************************************************
73,
Charlie?Sufana AJ9N
One of the ARISS operation team mentors
?
?
?
?
?
?
?
?
?
?
?
?
?
------------------------------
Message: 4
Date: Tue, 20 Mar 2018 16:34:51 +1300
From: "Wendy and Terry Osborne" <wandtosborne@?????.???>
To: "Burns Fisher" <burns@??????.??>, "Jean Marc Momple"
<jean.marc.momple@?????.???>
Cc: amsat-bb@?????.???
Subject: Re: [amsat-bb] Antenna Polarization Question
Message-ID: <C082A5C4E7314FC5835636E21FEB39DB@??????????>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi Burns, Jean Marc and Satellite Fans,
Here is my explanation of why Antenna Polarisation varies:
If the satellite is transmitting random linear polarisation then a CP
antenna should pick up most of the signal,
however remember that a CP antenna uses phasing between the Vertical and
Horizontal antennas to determine
the sense (RHCP or LHCP) of the circular polarisation.
If you consider the satellite to also have Vertical and Horizontal
components to its polarisation then how these
components change in phase when passing through the ionosphere determines
whether RHCP or LHCP will work better.
In addition there is the problem of reflections (ground and adjacent
objects) with the receiving antenna.
You can see this by looking a plots of the Vertical radiation pattern of
antennas at various heights.
At the low heights of typical satellite antennas any Horizontal component of
the received signal will vary
depending on the elevation angle of the satellite. Any Vertical component
will be pretty constant.
As an example AO-91 seems to work better with Vertical polarisation at low
elevation angles and changes to
Horizontal at high elevation angles (height above ground 1.5 metres).
So a satellite receiving antenna needs to be able to vary the polarisation
to be able to avoid fading at some elevation angles.
73,
Terry Osborne ZL2BAC
-----Original Message-----
From: Burns Fisher
Sent: Tuesday, March 20, 2018 7:33 AM
To: Jean Marc Momple
Cc: amsat-bb@?????.???
Subject: Re: [amsat-bb] Antenna Polarization Question
I'd really like to understand this better, but it is still not making sense
to me. I believe that if you are transmitting with a CP antenna, the E and
M waves actually go through an entire circle in one carrier cycle and a CP
antenna is able to "follow" that. Surely a satellite is not spinning at
anywhere close to 145 or 450 million revs per second, so I don't get
"spinning satellite" as an explanation for why an LHP or RHP antenna might
work better at different times.
What I do get is that a CP antenna can receive linearly polarized waves at
any angle equally. But this should be true whether the antenna is LHP or
RHP, and I would not think which direction should matter if the signal is
linear in the first place, even if the signal is spinning slowly.
That all said, I have definitely heard people say that they can get better
reception by changing from LHP to RHP. I'm not saying this is not true.
Just that I don't understand it.
73,
Burns WB1FJ
On Mon, Mar 19, 2018 at 1:57 PM, Jean Marc Momple <
jean.marc.momple@?????.???> wrote:
> Guys,
>
> Long debate for not much. I have followed this stream and believe that I
> need to intervene.
>
> It is very simple, most HAM birds does spin (sometimes a lot) and there is
> no way one can anticipate as different from one bird to others. It is just
> operator skills (on the spot) to determine/switch from LHCP or RCCP based
> on what is the best received signal strength. It works both on the Uplink
> and Downlink. There is no miracle formulae and it is a just operator
> skills
> as mentioned before.
>
> For commercial birds it is totally different game and should not be
> compared with our humble Ham birds, they have much more means to do things
> that we cannot afford to do, except if all HAM worldwide donate to AMSAT,
> say $10 we then may be able to match some of the features commercially
> available.
>
> Just a suggestion and food for thought.
>
>
> 73
>
>
> Jean Marc (3B8DU)
>
>
> > On Mar 19, 2018, at 8:54 PM, Franklin Antonio <antonio@???.????????.???>
> wrote:
> >
> > When you say a satellite "has" RHCP, we have to be careful that we're
> communicating clearly about what "has" means. Every satellite "has" both,
> by virtue of he way antennas work.
> >
> > I suspect that you mean that the satellite has an antenna which
> transmits RHCP in its main lobe. It is important to realize that the
> signal from such an antenna is only RHCP in its main lobe. The sidelobes
> are gonna be LHCP. In between, you can get anything in between. So if a
> satellite is oriented so that its antenna points right at you, and they
> designed it to be RHCP, then that's what you're gonna get, but if it is
> pointing off to the side, then you get something else.
> >
> > This means that there are situations in which you might get a stronger
> received signal if you switch to LHCP, or maybe even to linear. In the
> commercial satellite biz, they design satellites so that their antennas
> point at the users. Hams build cheaper satellites, which typically don't
> have sophisticated attitude control, so sometimes they point away from
> you. Also, hams try to use the things even when conditions aren't the
> best. If that's your aim, then most folks have found that polarization
> switching sometimes helps.
> >
> > ________________________________________
> > From: AMSAT-BB <amsat-bb-bounces@?????.???> on behalf of Jordan Trewitt
> <jmtrewitt@?????.???>
> > Sent: Sunday, March 18, 2018 2:43 PM
> > To: Eduardo PY2RN
> > Cc: amsat-bb@?????.???
> > Subject: Re: [amsat-bb] Antenna Polarization Question
> >
> > Maybe I'm not understanding it, but why does one need to switch between
> > both, unless a particular satellite has LHCP or RHCP?
> > Jordan
> > KF5COQ
> >
> > On Sun, Mar 18, 2018, 16:34 Eduardo PY2RN <py2rn@????.???> wrote:
> >
> >> Hi Brian,
> >> Both. You are going to need to switch between RHCP and LHCP often
> during a
> >> sat pass. The same happens if using linear polarization (V/H) but in
> this
> >> case the switch between V and H will happen much more often than in CP.
> >> 73
> >> Ed
> >> PY2RN
> >>
> >> From: Brian via AMSAT-BB <amsat-bb@?????.???>
> >> To: "amsat-bb@?????.???? <amsat-bb@?????.???>
> >> Sent: Sunday, March 18, 2018 6:21 PM
> >> Subject: [amsat-bb] Antenna Polarization Question
> >>
> >>
> >>
> >> Should I be using LHCP or RHCP when setting up the 2 meter and 440
> yagi's
> >> to work the LEO's.
> >>
> >> Thank you
> >>
> >> Brian, KG8CO
> >>
> >> _______________________________________________
> >> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> >> to all interested persons worldwide without requiring membership.
> Opinions
> >> expressed
> >> are solely those of the author, and do not reflect the official views
> >> of
> >> AMSAT-NA.
> >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >>
> >>
> >>
> >> _______________________________________________
> >> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> >> to all interested persons worldwide without requiring membership.
> Opinions
> >> expressed
> >> are solely those of the author, and do not reflect the official views
> >> of
> >> AMSAT-NA.
> >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >>
> > _______________________________________________
> > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> > _______________________________________________
> > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
_______________________________________________
Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 5
Date: Tue, 20 Mar 2018 01:30:23 -0400
From: aj9n@???.???
To: amsat-bb@?????.???
Subject: [amsat-bb] Upcoming ARISS Contact Schedule as of 2018-03-20
05:30 UTC
Message-ID: <16241e314bb-c89-bc3@?????????????.???.???????.???>
Content-Type: text/plain; charset=utf-8
Upcoming ARISS Contact Schedule as of 2018-03-20 05:30 UTC
Quick list of scheduled contacts and events:
?
Templestowe Valley Primary School, Templestowe, Victoria, Australia,
telebridge via VK4KHZ
The ISS callsign is presently scheduled to be NA1SS
The scheduled astronaut is Scott Tingle KG5NZA
Contact was successful: Mon 2018-03-19 08:43:46 UTC 27 deg (***)
?
Watch for live stream on the EchoLink AMSAT conference server live.??
Freeport Public Schools, Freeport, NY, telebridge via IK1SLD (***)
The ISS callsign is presently scheduled to be OR4ISS (***)
The scheduled astronaut is Scott Tingle KG5NZA (***)
Contact is a go for: Tue 2018-03-27 17:41:04 UTC 24 deg (***)
******************************************************************************
International Space Station Astronauts are Calling CQ Students? (corrected)?
(***)
????????????? ?ARISS-US program education proposal deadline is April 30, 2018
?
March 15, 2018:? The Amateur Radio on the International Space Station
(ARISS) program is seeking proposals from US schools, museums, science
centers and community youth organizations (working individually or together)
to host radio contacts with an orbiting crew member aboard the International
Space Station (ISS) between January 1 and June 30, 2019.
?
Each year, ARISS provides tens of thousands of students with opportunities
to learn about space technologies and communications through the exploration
of Amateur Radio. ?The program provides learning opportunities by connecting
students to astronauts aboard the International Space Station (ISS) through
a partnership between NASA, the Radio Amateur Satellite Corporation, the
American Radio Relay League, and other Amateur Radio organizations and
worldwide space agencies. The program?s goal is to inspire students to
pursue interests and careers in science, technology, engineering and
mathematics (STEM) and Amateur Radio. A ham recently said, ?ARISS shows how
Amateur Radio is the most unique hobby/service there is.?
?
Educators overwhelmingly report that student participation in the ARISS
program stimulates interest in STEM subjects and in STEM careers. One
educator wrote, ?It exceeded our expectations--it created a great interest
in both amateur radio and in space exploration. Our kids are completely
inspired!? Ninety-two percent of educators who have participated in the
program have indicated that ARISS provided ideas for encouraging student
exploration and participation. An educator even joined the ham ranks,
saying, ?This chance for our school?s ARISS contact helped me see the great
value of the ham world.? I just passed my Technician License this weekend
and have already signed up to take a General class.?? ?
ARISS is looking for organizations that will draw large numbers of
participants and integrate the contact into a well-developed, exciting
education plan. Students can learn about satellite communications, wireless
technology, science research conducted on the ISS, radio science, and any
related STEM subject. Students learn to use Amateur Radio to talk directly
to an astronaut and ask their STEM-related questions. ARISS will help
educational organizations locate Amateur Radio groups who can assist with
equipment for this once-in-a-lifetime opportunity for students.
The proposal deadline for 2019 contacts is April 30, 2018. Proposal webinars
for guidance and getting questions answers will be offered March 29, 2018,
at 7 p.m. EDT and April 16, 2018, at 4 p.m. EDT. Advance registration is
necessary. To sign up, go to
https://ariss-proposal-webinar-spring-2018.eventbrite.com
For more details such as expectations, proposal guidelines and the proposal
form, visit: http://www.ariss.org/hosting-an-ariss-contact-in-the-us.html
?
******************************************************************************
ARISS is always glad to receive listener reports for the above contacts.?
ARISS thanks everyone in advance for their assistance.? Feel free to send
your reports to aj9n@?????.??? or aj9n@???.???.
?
Listen for the ISS on the downlink of 145.8? MHz.
?
******************************************************************************
*
?
All ARISS contacts are made via the Kenwood radio unless otherwise noted.
?
******************************************************************************
*
Several?of you have sent me emails asking about the RAC ARISS website and
not being able?to get in.? That has now been changed to?
http://www.ariss.org/
Note that there are links to other ARISS websites from this?site.
****************************************************************************
Looking?for something new to do?? How about receiving DATV from the ISS???
If interested, then please go to the ARISS-EU website for complete?
details.? Look for the buttons indicating Ham?Video.? ? ? ? ? ? ? ? ? ? ? ?
? ?
? ? ? ? ? ? ? ? ? ? ?
http://www.ariss-eu.org/? ?
?
If you need some assistance, ARISS mentor Kerry N6IZW, might be able to
provide some insight.? Contact Kerry at kbanke@?????????.???
****************************************************************************
ARISS congratulations the following mentors who have now mentored over 100
schools:?
Francesco IK?WGF with 132
Satoshi 7M3TJZ with 128
Gaston ON4WF with 123
Sergey RV3DR with 102
****************************************************************************
The?webpages listed below were all reviewed for accuracy.? Out of date
webpages?were removed and new ones have been added.? If there are additional
ARISS?websites I need to know about, please let me know.
Note, all times?are approximate.? It is recommended that you do your own
orbital prediction?or start listening about 10 minutes before the listed
time.
All dates and?times listed follow International Standard ISO 8601 date and
time format? YYYY-MM-DD HH:MM:SS
The complete schedule page has been updated as of?2018-03-20 05:30 UTC.? (***)
Here you will find a listing of all scheduled?school contacts, and
questions, other ISS related websites, IRLP and?Echolink websites, and
instructions for any contact that may be streamed?live.??
http://www.amsat.org/amsat/ariss/news/arissnews.rtf
http://www.amsat.org/amsat/ariss/news/arissnews.txt
Total number?of ARISS ISS to earth school events is 1216. (***)
Each school counts as 1?event.
Total number of ARISS ISS to earth school contacts is 1165. (***)
Each contact may have multiple schools sharing the same time slot.
Total number of ARISS supported terrestrial contacts is?47.
A complete year by year breakdown of the contacts may be found in the
file.
http://www.amsat.org/amsat/ariss/news/arissnews.rtf
Please?feel free to contact me if more detailed statistics are needed.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The?following US states and entities have never had an ARISS contact:
Arkansas,?Delaware, South Dakota, Wyoming, American?Samoa, Guam, Northern
Marianas Islands, and the Virgin Islands.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
QSL?information may be found at:??
http://www.ariss.org/qsl-cards.html?
ISS callsigns:? DP?ISS, IR?ISS, NA1SS, OR4ISS,?RS?ISS
****************************************************************************
The successful school list has been updated as of 2018-03-20 03:00 UTC. (***)
http://www.amsat.org/amsat/ariss/news/Successful_ARISS_schools.rtf
Frequency? chart for packet, voice, and crossband repeater modes showing
Doppler? correction? as of 2005-07-29 04:00 UTC
http://www.amsat.org/amsat/ariss/news/ISS_frequencies_and_Doppler_correction
.rtf
Listing?of ARISS related magazine articles as of 2006-07-10 03:30 UTC.
http://www.amsat.org/amsat/ariss/news/ARISS_magazine_articles.rtf
Check out the Zoho reports of the ARISS?contacts
https://reports.zoho.com/ZDBDataSheetView.cc?DBID=412218000000020415
****************************************************************************
Exp. 54 on orbit
Scott Tingle KG5NZA
Norishige Kanai
Alexander Skvortsov
****************************************************************************
73,
Charlie?Sufana AJ9N
One of the ARISS operation team mentors
?
?
?
?
?
?
?
?
?
?
?
?
?
------------------------------
Message: 6
Date: Tue, 20 Mar 2018 15:40:13 +0000
From: Franklin Antonio <antonio@???.????????.???>
To: Burns Fisher <burns@??????.??>
Cc: "amsat-bb@?????.???? <amsat-bb@?????.???>
Subject: Re: [amsat-bb] Antenna Polarization Question
Message-ID: <1521560413766.2662@???.????????.???>
Content-Type: text/plain; charset="iso-8859-1"
I'll double down on the explanation I wrote below, because I believe it
addresses the issue you're having trouble with. However, I've figured out
another way to say the same thing using different perhaps more familiar
language. Here goes...
Suppose we have a satellite that transmits (so they say) a Right Hand
Circular Polarized signal. That means the electric vector spins around in a
counterclockwise direction. Ah, but clockwise is an interesting concept.
Lets think about a clock.
Suppose I launched a giant clock into orbit. It is big enough so that you
can see it with a telescope, and it has a transparent face. What you see in
the telescope are the giant clock hands.
As you look thru the telescope, fred asks you "Which way do the clock hands
rotate? Clockwise or counterclockwise?" Now it happens that at this moment
the clock is oriented so that you're looking at it from the side. You
respond "I don't know. I don't see any rotation. They seem to be going
just up and down!"
Then after awhile the clock's orientation has changed a bit, and now you can
see rotation. You say "hey, now I see rotation, and it's clockwise!" You
are now looking at the front of the clock.
The clock itself is slowly rotating so after awhile you say "Hey, its just
going up and down again!" This means that the clock has now rotated so that
you're seeing it edge-on again, from the other side.
After another wait you say "Wow, now I see rotation again, but now it's
counterclockwise! It changed! How can that be?" This just means you're
now seeing the clock from the back instead of the front. When you look from
the back side, the clockwise rotation of the clock looks like
counterclockwise rotation.
How the signal from an antenna on a spacecraft looks to you works the same
way, except we use different names. Clockwise rotation is LHCP.
Counterclockwise rotation is RHCP. Up-and-down movement is linear
polarization.
If you ask a clock designer which way he built the clock to go, he'll think
you're an idiot, and he'll say "clockwise of course". But keep in mind
he's speaking under the assumption that you view his clock from the front.
He doesn't say this, but he means it nevertheless.
If you ask a designer of an antenna which polarization he designed the
antenna to generate, he may say "RHCP", but keep in mind he's speaking under
the assumption that you view his antenna from the front (ie in the main
beam). If you're viewing from the side or the back, the answer is different.
If you view a transmitting antenna or a clock from a different direction,
then you see a different rotation or polarization.
You can write a bunch of complicated equations to describe all this, but at
its heart its just simple geometry.
________________________________
From: Burns Fisher <burns@??????.??>
Sent: Monday, March 19, 2018 11:33 AM
To: Jean Marc Momple
Cc: Franklin Antonio; amsat-bb@?????.???
Subject: Re: [amsat-bb] Antenna Polarization Question
I'd really like to understand this better, but it is still not making sense
to me. I believe that if you are transmitting with a CP antenna, the E and
M waves actually go through an entire circle in one carrier cycle and a CP
antenna is able to "follow" that. Surely a satellite is not spinning at
anywhere close to 145 or 450 million revs per second, so I don't get
"spinning satellite" as an explanation for why an LHP or RHP antenna might
work better at different times.
What I do get is that a CP antenna can receive linearly polarized waves at
any angle equally. But this should be true whether the antenna is LHP or
RHP, and I would not think which direction should matter if the signal is
linear in the first place, even if the signal is spinning slowly.
That all said, I have definitely heard people say that they can get better
reception by changing from LHP to RHP. I'm not saying this is not true.
Just that I don't understand it.
73,
Burns WB1FJ
On Mon, Mar 19, 2018 at 1:57 PM, Jean Marc Momple
<jean.marc.momple@?????.???<???????????.????.??????@?????.???>> wrote:
Guys,
Long debate for not much. I have followed this stream and believe that I
need to intervene.
It is very simple, most HAM birds does spin (sometimes a lot) and there is
no way one can anticipate as different from one bird to others. It is just
operator skills (on the spot) to determine/switch from LHCP or RCCP based on
what is the best received signal strength. It works both on the Uplink and
Downlink. There is no miracle formulae and it is a just operator skills as
mentioned before.
For commercial birds it is totally different game and should not be compared
with our humble Ham birds, they have much more means to do things that we
cannot afford to do, except if all HAM worldwide donate to AMSAT, say $10 we
then may be able to match some of the features commercially available.
Just a suggestion and food for thought.
73
Jean Marc (3B8DU)
> On Mar 19, 2018, at 8:54 PM, Franklin Antonio
<antonio@???.????????.???<??????????????@???.????????.???>> wrote:
>
> When you say a satellite "has" RHCP, we have to be careful that we're
communicating clearly about what "has" means. Every satellite "has" both,
by virtue of he way antennas work.
>
> I suspect that you mean that the satellite has an antenna which transmits
RHCP in its main lobe. It is important to realize that the signal from such
an antenna is only RHCP in its main lobe. The sidelobes are gonna be LHCP.
In between, you can get anything in between. So if a satellite is oriented
so that its antenna points right at you, and they designed it to be RHCP,
then that's what you're gonna get, but if it is pointing off to the side,
then you get something else.
>
> This means that there are situations in which you might get a stronger
received signal if you switch to LHCP, or maybe even to linear. In the
commercial satellite biz, they design satellites so that their antennas
point at the users. Hams build cheaper satellites, which typically don't
have sophisticated attitude control, so sometimes they point away from you.
Also, hams try to use the things even when conditions aren't the best. If
that's your aim, then most folks have found that polarization switching
sometimes helps.
>
> ________________________________________
> From: AMSAT-BB
<amsat-bb-bounces@?????.???<???????????????????????@?????.???>> on behalf of
Jordan Trewitt <jmtrewitt@?????.???<????????????????@?????.???>>
> Sent: Sunday, March 18, 2018 2:43 PM
> To: Eduardo PY2RN
> Cc: amsat-bb@?????.???<???????????????@?????.???>
> Subject: Re: [amsat-bb] Antenna Polarization Question
>
> Maybe I'm not understanding it, but why does one need to switch between
> both, unless a particular satellite has LHCP or RHCP?
> Jordan
> KF5COQ
>
> On Sun, Mar 18, 2018, 16:34 Eduardo PY2RN
<py2rn@????.???<????????????@????.???>> wrote:
>
>> Hi Brian,
>> Both. You are going to need to switch between RHCP and LHCP often during a
>> sat pass. The same happens if using linear polarization (V/H) but in this
>> case the switch between V and H will happen much more often than in CP.
>> 73
>> Ed
>> PY2RN
>>
>> From: Brian via AMSAT-BB
<amsat-bb@?????.???<???????????????@?????.???>>
>> To: "amsat-bb@?????.???<???????????????@?????.???>"
<amsat-bb@?????.???<???????????????@?????.???>>
>> Sent: Sunday, March 18, 2018 6:21 PM
>> Subject: [amsat-bb] Antenna Polarization Question
>>
>>
>>
>> Should I be using LHCP or RHCP when setting up the 2 meter and 440 yagi's
>> to work the LEO's.
>>
>> Thank you
>>
>> Brian, KG8CO
>>
>> _______________________________________________
>> Sent via AMSAT-BB@?????.???<???????????????@?????.???>. AMSAT-NA makes
this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>
>>
>>
>> _______________________________________________
>> Sent via AMSAT-BB@?????.???<???????????????@?????.???>. AMSAT-NA makes
this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>
> _______________________________________________
> Sent via AMSAT-BB@?????.???<???????????????@?????.???>. AMSAT-NA makes
this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@?????.???<???????????????@?????.???>. AMSAT-NA makes
this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________
Sent via AMSAT-BB@?????.???<???????????????@?????.???>. AMSAT-NA makes this
open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@?????.???.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT member? Join now to support the amateur satellite program!
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 13, Issue 109
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