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CX2SA > SATDIG 25.08.10 21:03l 809 Lines 28084 Bytes #999 (0) @ WW
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Sent: 100825/1903Z @:CX2SA.LAV.URY.SA #:15810 [Minas] FBB7.00e $:AMSATBB5352
From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. AMSAT at the NASM (Hispanic Heritage Month) - October 16,
2010, First call for volunteers (Samudra Haque)
2. Fw: Lighthouse/Lightship Special Event 8/21-8/22
(Peter Portanova)
3. Fw: Fw: Lighthouse/Lightship Special Event 8/21-8/22
(Peter Portanova)
4. Re: AMSAT at the NASM (Hispanic Heritage Month) - October 16,
2010, First call for volunteers (Mark L. Hammond)
5. AO-51 recording 1140Z this morning (Matt Patterson)
6. AO-7 Point to ponder. (John Hackett)
7. Posting to BB (Tom Jones)
8. Re: AO-51 recording 1140Z this morning (Zachary Beougher)
9. Circular Polarized Antennae (Spectrum International, Inc)
10. Re: Posting to BB (GW1FKY@xxx.xxxx
11. New Satellite Downlink? (Robert Bruninga)
12. Re: Posting to BB (Andreas Junge)
13. Re: Circular Polarized Antennae (Jeff Moore)
14. Operation from IN70 (Gabriel - EA6VQ)
15. QSP (John Hackett)
----------------------------------------------------------------------
Message: 1
Date: Tue, 24 Aug 2010 15:55:30 -0400
From: Samudra Haque <samudra.haque@xxxxx.xxx>
Subject: [amsat-bb] AMSAT at the NASM (Hispanic Heritage Month) -
October 16, 2010, First call for volunteers
To: Amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID:
<AANLkTimNkWfkoxbUzx5FzhecJ5SOVnpkL4Tz8+ETmO3M@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
Hello AMSAT-NA and others,
if you are interested in volunteering for AMSAT outreach activities, please
consider the following event that is being organized by the National Air and
Space Museum in Washington, DC. The last event at the NASM was Space Day,
which included a live ARISS contact and AMSAT display stands with a variety
of equipment and presentations.
Event: Hispanic Heritage Month Family day?Argentina in Air and Space
Location: National Air and Space Museum
Date: Saturday, October 16, 2010
Time: 10 AM ? 3 PM
I am volunteering to organize AMSAT's participation for the event. Please
contact me through e-mail if you are interested and able to participate in
any form. I will need to know:
* Can you volunteer any exhibition/display resources (pictures, posters,
etc.) ?
* Can you volunteer your time on October 16, 2010 for any portion?
* Can you provide any presentation materials relevant to Argentina in Air
and Space?
* Will you require transportation? etc. etc.
Additional info from NASM:
NASM is looking for AMSAT members who would be interested in talking to the
visitors about satellites. Because the focus of the day is Argentina, we
are particularly interested in people with expertise in Argentinean
satellites. Bonus points for members how can discuss Pehuensat-1 because
Pablo de Leon, who was the payload manager, will be a featured speaker at
the event.
Expectations: AMSAT members would set-up tables with equipment, posters, and
other items of interest to visitors. These tables would be staffed
throughout the day by AMSAT members. You are welcome to volunteer for a
couple of hours or the whole day. Free parking will be provided all, and
lunch will be provided for people who volunteer the whole day.
This event will celebrate both the centennial and bicentennial of
Argentina. For the centennial celebration we will focus on Jorge Newberry
and lighter than air.
For the bicentennial (which is this year) the focus will be on Argentina?s
accomplishments in space. The linchpin of this portion of the program will
be Pablo de Leon. He has been involved with a number of projects for the
NASA and CONAE. Based on his accomplishments a special feature will focus
on space suit design, development and production?ILC Dover has agreed to
bring some of the people who make the actual suits. I have already outlined
some of his involvement in satellites. In addition to that, CONAE is
sending a large model of the SAC-D satellite and I am hopeful to have some
the Aquarius team involved as well.
73 de N3RDX
Samudra Haque
Alexandria, VA 22310
(202) 812-3325
samudra.haque@xxxxx.xxx
------------------------------
Message: 2
Date: Tue, 24 Aug 2010 17:25:18 -0400
From: Peter Portanova <roic@xxxxxxxxx.xxx>
Subject: [amsat-bb] Fw: Lighthouse/Lightship Special Event
8/21-8/22
To: amsAT-BB@xxxxx.xxx
Cc: john melfi <radiorights@xxxxx.xxx>
Message-ID: <766E8D92D37140A3859E107C4D31F93A@xxxx>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Hello,
On behalf of the Great South Bay Amateur Club, I want to thank all the
terrific satellite operators who participated in Lighthouse/Lightship
weekend, with the W2GSB/LH call. We made a total of 63 contacts, 15 States
and two countries on FM. I had a terrific time in spite of the occasional
rain and wind, we had good crowds on some of the passes that were in awe of
a small antenna and radio talking in space, thank you very much, pictures
will be in a future Amsat journal showing this beautiful location.
The event under the leadership of our President, W2HCB, John, a satellite
convert, was fun for all..
If you want a very nice QSL of your contact, go to www.gsbarc.orf, for
mailing information.
73- Pete
WB2OQQ
------------------------------
Message: 3
Date: Tue, 24 Aug 2010 17:53:50 -0400
From: Peter Portanova <roic@xxxxxxxxx.xxx>
Subject: [amsat-bb] Fw: Fw: Lighthouse/Lightship Special Event
8/21-8/22
To: amsAT-BB@xxxxx.xxx
Cc: john melfi <radiorights@xxxxx.xxx>
Message-ID: <2C2060BC53874B2BA33A0592DB18D823@xxxx>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
The website for QSL's cards is www.gsbarc.org
73- Pete
WB2OQQ
------------------------------
Message: 4
Date: Tue, 24 Aug 2010 19:15:16 -0400
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: AMSAT at the NASM (Hispanic Heritage Month) -
October 16, 2010, First call for volunteers
To: Samudra Haque <samudra.haque@xxxxx.xxx>, Amsat-bb
<amsat-bb@xxxxx.xxx>
Message-ID: <yPFF1e00756cfur05PFHXj@xxxxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
I'm sorry I can't help with the event, but LO-19 is surely worthy of
attention:
http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=12
I know the CW transmitter has been off for months, but I swear I have seen
see a faint carrier using a sound card and Spectran.
Anyhow, AMSAT has certainly partnered with AMSAT-LU during the microsat era.
73,
Mark N8MH
At 03:55 PM 8/24/2010 -0400, Samudra Haque wrote:
>Hello AMSAT-NA and others,
>
>
>if you are interested in volunteering for AMSAT outreach activities, please
>consider the following event that is being organized by the National Air and
>Space Museum in Washington, DC. The last event at the NASM was Space Day,
>which included a live ARISS contact and AMSAT display stands with a variety
>of equipment and presentations.
>
>
>Event: Hispanic Heritage Month Family day?Argentina in Air and Space
>
>Location: National Air and Space Museum
>
>Date: Saturday, October 16, 2010
>
>Time: 10 AM ? 3 PM
>
>
>I am volunteering to organize AMSAT's participation for the event. Please
>contact me through e-mail if you are interested and able to participate in
>any form. I will need to know:
>
>
>* Can you volunteer any exhibition/display resources (pictures, posters,
>etc.) ?
>
>* Can you volunteer your time on October 16, 2010 for any portion?
>
>* Can you provide any presentation materials relevant to Argentina in Air
>and Space?
>
>* Will you require transportation? etc. etc.
>
>
>Additional info from NASM:
>
>
>NASM is looking for AMSAT members who would be interested in talking to the
>visitors about satellites. Because the focus of the day is Argentina, we
>are particularly interested in people with expertise in Argentinean
>satellites. Bonus points for members how can discuss Pehuensat-1 because
>Pablo de Leon, who was the payload manager, will be a featured speaker at
>the event.
>
>
>Expectations: AMSAT members would set-up tables with equipment, posters, and
>other items of interest to visitors. These tables would be staffed
>throughout the day by AMSAT members. You are welcome to volunteer for a
>couple of hours or the whole day. Free parking will be provided all, and
>lunch will be provided for people who volunteer the whole day.
>
>
>This event will celebrate both the centennial and bicentennial of
>Argentina. For the centennial celebration we will focus on Jorge Newberry
>and lighter than air.
>
>
>
>For the bicentennial (which is this year) the focus will be on Argentina?s
>accomplishments in space. The linchpin of this portion of the program will
>be Pablo de Leon. He has been involved with a number of projects for the
>NASA and CONAE. Based on his accomplishments a special feature will focus
>on space suit design, development and production?ILC Dover has agreed to
>bring some of the people who make the actual suits. I have already outlined
>some of his involvement in satellites. In addition to that, CONAE is
>sending a large model of the SAC-D satellite and I am hopeful to have some
>the Aquarius team involved as well.
>
>
>73 de N3RDX
>
>
> Samudra Haque
>
>Alexandria, VA 22310
>
>(202) 812-3325
>
>samudra.haque@xxxxx.xxx
>_______________________________________________
>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: 5
Date: Wed, 25 Aug 2010 06:58:11 -0500
From: "Matt Patterson" <mattpatt@xxxxxxxx.xxx>
Subject: [amsat-bb] AO-51 recording 1140Z this morning
To: <amsAT-BB@xxxxx.xxx>
Message-ID: <000201cb444c$cacb8590$606290b0$@xxx>
Content-Type: text/plain; charset="us-ascii"
Hi Everyone,
Still getting used to working the sats and was curious if someone happened
to be recording the latest AO-51 pass over North America. For me AOS
started at around 1140Z. If you do have a recording, would you mind sharing
with me? Curious to see how I sound on the other end.
73 Matt
W5LL
------------------------------
Message: 6
Date: Wed, 25 Aug 2010 11:24:13 +0200
From: John Hackett <archie.hackett@xxxxxxx.xxx>
Subject: [amsat-bb] AO-7 Point to ponder.
To: <eu-amsat@xxxxxxxxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <SNT104-W15293373357953A45A8C691840@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
AO-7 has now operated longer this second time around ... (compared to the
first time from the 1974 era).
Details on the AO-7 Resource Page.
73 John. <la2qaa@xxxxx.xxx>
------------------------------
Message: 7
Date: Wed, 25 Aug 2010 09:30:03 -0400
From: "Tom Jones" <Tom.Jones@xxxxxx.xxx>
Subject: [amsat-bb] Posting to BB
To: AMSAT-BB@xxxxx.xxx
Message-ID:
<OF54DE31F0.255AF62C-ON8525778A.00494A0A-8525778A.004A28B0@xxxxxxxxxxx>
Content-Type: text/plain; charset="US-ASCII"
Folks
I am searching for hardware to interface my laptop to the Yaesu rotor
G-5500 or G-550. I use SatPC32 software. What is the latest and greatest
hardware to do this? I know that the KCT unit is no longer made.
Regards
Tom
KC2DTQ
------------------------------
Message: 8
Date: Wed, 25 Aug 2010 10:33:29 -0400
From: "Zachary Beougher" <zack.kd8ksn@xxxxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 recording 1140Z this morning
To: "Matt Patterson" <mattpatt@xxxxxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Message-ID: <SNT111-DS208B0EAF4EF28E433573C3B3840@xxx.xxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I am copying the BB on this as well (I am performing a test with this
message).
Matt - I do have the recording. Let me get it onto the PC and I will get it
off to you.
73,
Zack
KD8KSN
EN80sd
--------------------------------------------------
From: "Matt Patterson" <mattpatt@xxxxxxxx.xxx>
Sent: Wednesday, August 25, 2010 7:58 AM
To: <amsAT-BB@xxxxx.xxx>
Subject: [amsat-bb] AO-51 recording 1140Z this morning
> Hi Everyone,
>
> Still getting used to working the sats and was curious if someone happened
> to be recording the latest AO-51 pass over North America. For me AOS
> started at around 1140Z. If you do have a recording, would you mind
> sharing
> with me? Curious to see how I sound on the other end.
>
> 73 Matt
> W5LL
>
>
> _______________________________________________
> 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: 9
Date: Wed, 25 Aug 2010 14:49:25 +0000
From: "Spectrum International, Inc" <spectrum.ma.ultranet@xxx.xxx>
Subject: [amsat-bb] Circular Polarized Antennae
To: John Hackett_LA2QAA <archie.hackett@xxxxxxx.xxx>
Cc: la2qaa@xxxxx.xxxx AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <4C752D75.9020401@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
John, LA2QAA
That was an interesting message you posted to
the -bb this morning. It has many true observations; however there is
one serious mistake, an unforgivable error.
Quote:
......... particularly by the newcomers - who
apparently, and mistakenly, think that high power is necessary.
It's *NOT* . . . nor is an EME class aerial array necessary to work
the LEO satellites. Ditto circular polarisation.
FACT: polarisation is *ONLY* circular along the boresight of an aerial.
Unquote.
Your polarization statement is not 100% accurate.
Unfortunately most antenna manufacturers, who supply/sell "alleged
circular" polarized antennas do not state that their antennas are
circular polarized ONLY along the boresight. They conveniently (?) do
not mention that their alleged "circular polarized" antenna is only
circular polarized on boresight, that it is linear polarized at 90
degrees off of boresight and is elliptical polarized of varying ratio at
all angles in between!
There is however one (and only one that I am aware of)
antenna design that is circular polarized over its entire radiation
pattern. I refer you to the Q_uadrifilar Helix Antenna_ described by Dr.
C.C.Kilgus in IEEE Trans., Vol. AP-16, July 1968, pp. 499-500. Also
Bricker, R.W. and Rickert, H.H., in RCA Engineer, Vol.20, No. 5,
February/March 1975. There is an excellent review by Walter Maxwell,
W2DU, at http://www.IAG.net/~w2du/quadfinal.pdf.
When installed pointing to the zenith, the "ideal,
theoretical" Quad Helix has 360 degree coverage in the azimuthal plane
and 90 degree coverage in the elevation plane. It is circularly
polarized over the entire upper hemisphere. There is no radiation in the
lower hemi-sphere; the energy in the lower hemi-sphere of an isotropic
radiator is uniformly distributed over the upper hemi-sphere. Hence the
gain of an "ideal" Quad Helix is 3.01 dBi. However you can modify the
elevation pattern to give more gain at the horizon and less gain
overhead by adjustment of the overall length to diameter ratio. It is
possible to adjust this ratio to give constant signal amplitude, at an
earth based receiving station, from a satellite in a circular orbit
where the range ratio (and hence signal path attenuation) between AOS
and the zenith can be significant. This results in a little radiation
below the horizon and also avoids the nasty mathematical boundary value
problem at the horizon in the ideal case.
Quadrifilar Helix antennas are used on many LEO
satellites for VHF, UHF, L-band and S-band communication. One of
their parameters of interest to satellite builders is that they do NOT
require a "ground plane" provided they are at least a quarter wavelength
above the satellite structure. Hence there is negligible critical
location requirement and they do not occupy satellite surface area that
is required for solar cells.
The Quadrifilar Helix antenna is popular with earth
based receiving stations for receiving the VHF image data signals from
the NOAA weather satellites. Right-hand circular Quad Helix antennas for
the 137MHz NOAA weather image signals and 137MHz left-hand circular Quad
Helix antennas for receiving the ARGOS programme signals, are available
from Spectrum International, Inc. Spectrum also supplies both right-hand
and left-hand versions for the 2M and 70cm Amateur radio bands.
May we suggest you sprinkle some "Grow More fertilizer"
around the base of your "chopped down satellite array" every Sunday
morning and offer a few words of wisdom while so doing. With a little
help and the dregs of Saturday night's Black and Tan, your mini array
might grow.
Regards, Spectrum.
------------------------------
Message: 10
Date: Wed, 25 Aug 2010 11:16:20 EDT
From: GW1FKY@xxx.xxx
Subject: [amsat-bb] Re: Posting to BB
To: Tom.Jones@xxxxxx.xxxx AMSAT-BB@xxxxx.xxx
Message-ID: <f8455.734d8e33.39a68dc4@xxx.xxx>
Content-Type: text/plain; charset="US-ASCII"
Hi Tom,
The "LVB Tracker Box" designed by Howard Long has a very good reputation
and will work well with SatPC32 and other software.
It is available in kit form in various options or ready built from Amsat.
It also has either a serial port or USB
port option. You will need to download a driver for the USB version from
the site mentioned in the intructions.
Both the Amsat NA and Amsat -UK have published information about its use
in their journals and web pages.
Good Luck
Ken Eaton
GW1FKY
Amsat -UK
Amsat NA
------------------------------
Message: 11
Date: Wed, 25 Aug 2010 12:27:00 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] New Satellite Downlink?
To: <amsat-bb@xxxxx.xxx>
Message-ID: <3DEE29EBEB7F407C97AFEA744C8B95D5@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Possible new AMSAT Application?
We may have access to two old TRANSIT navigation satellites with
a 50 baud downlink at 149.985 (and 400 MHz). (presently coming
over in the mid afternoon). My problem is, coming up with any
meaningful application to use them for communications that would
capture the interest of students, hams or volunteers in support
of education, public service or emergency comms or just plain
fun...
The downlink can be heard on an OMNI antenna (though I would
suggest a 3/4 wave (55") vertical) and could be decoded by a
simple software only application with a sound card. (someone has
to write it)...
The total useful message capability is about 500 bytes
transmitted every 2 minutes (at 50 baud). The uplink is very
specialized and can ONLY BE DONE from one (or two) very special
commmand stations. These satellites of course were the original
Navy Navigation satellite system (also called OSCARS) and so the
message would be in-place of the normal navigation data. SO in
a sense, this is a downlink BROADCAST application. Since ham
radio is two way, I'm stumped for applications.
The total message capability of 500 Bytes can contain one long
ARRL bulletin, or 20 APRS position/status reports, or say 20 or
so APRS text messages, or say 50 "callsign exchanges" or maybe
even 1 thumbnail image... but what's the application?
Even if we allow say, INTERNET link to the command station for
"anyone" to contribute to the twice per-day upload, then
everyone's receiver application can receive them... For what?
So Im looking for ideas. All I can come up with so far is:
1) ARRL Bulletins? (I don't even know how often ARRL sends
bulletins...)
2) Navy/Army/AF MARS broadcast bulletins...
3) Internet message in-to-command-upload-to message RF downlink.
Two stations do this to each other and it counts as a two-way
QSO?
4) ...
Every scenario of interest usually begins with the much higher
value of UPLINK from the individual field station, not
downlink.. Hence I am stumped.
HUMMH... Maybe purely educational? If the software can run on
any PC with a sound card connected to any scanner... Then every
school can use it as a satellite downlink signal of interest..
What kind of thumbnail image can fit in 500 bytes? Send in your
picture and get it downlinked on a given day?
Etc..
Will need a DSP volunteer to write the sound card decoder.
Bob, WB4APR
------------------------------
Message: 12
Date: Wed, 25 Aug 2010 09:30:46 -0700
From: Andreas Junge <andreas@xxxx.xxx>
Subject: [amsat-bb] Re: Posting to BB
To: Tom Jones <Tom.Jones@xxxxxx.xxx>
Cc: AMSAT-BB@xxxxx.xxx
Message-ID: <0E0BD4CD-C5EB-4A22-9934-F9EAC87549F9@xxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Tom,
you can get the LVB tracker as plug-and-play ready assembled unit from the
Amsat US store:
http://www.amsat-na.com/store/item.php?id=100151
I use mine with SatPC32 and a G5500. I could not be happier.
73,
Andreas, N6NU
On Aug 25, 2010, at 6:30 AM, Tom Jones wrote:
> Folks
>
> I am searching for hardware to interface my laptop to the Yaesu rotor
> G-5500 or G-550. I use SatPC32 software. What is the latest and greatest
> hardware to do this? I know that the KCT unit is no longer made.
> Regards
> Tom
> KC2DTQ
>
> _______________________________________________
> 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, 25 Aug 2010 09:58:27 -0700
From: "Jeff Moore" <tnetcenter@xxxxx.xxx>
Subject: [amsat-bb] Re: Circular Polarized Antennae
To: "Spectrum International, Inc" <spectrum.ma.ultranet@xxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <DE529F5BF2A04CE690C6A6C61D3BA08A@xxxxxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
If you're going to post an ad, you should at least provide the proper
contact info like web-site etc. so that we can take a look at your
products - don't leave us hanging.
Jeff Moore -- KE7ACY
CN94
----- Original Message ----- From: "Spectrum International, Inc"
<spectrum.ma.ultranet@xxx.xxx>
John, LA2QAA
That was an interesting message you posted to
the -bb this morning. It has many true observations; however there is
one serious mistake, an unforgivable error.
Quote:
......... particularly by the newcomers - who
apparently, and mistakenly, think that high power is necessary.
It's *NOT* . . . nor is an EME class aerial array necessary to work
the LEO satellites. Ditto circular polarisation.
FACT: polarisation is *ONLY* circular along the boresight of an aerial.
Unquote.
Your polarization statement is not 100% accurate.
Unfortunately most antenna manufacturers, who supply/sell "alleged
circular" polarized antennas do not state that their antennas are
circular polarized ONLY along the boresight. They conveniently (?) do
not mention that their alleged "circular polarized" antenna is only
circular polarized on boresight, that it is linear polarized at 90
degrees off of boresight and is elliptical polarized of varying ratio at
all angles in between!
There is however one (and only one that I am aware of)
antenna design that is circular polarized over its entire radiation
pattern. I refer you to the Q_uadrifilar Helix Antenna_ described by Dr.
C.C.Kilgus in IEEE Trans., Vol. AP-16, July 1968, pp. 499-500. Also
Bricker, R.W. and Rickert, H.H., in RCA Engineer, Vol.20, No. 5,
February/March 1975. There is an excellent review by Walter Maxwell,
W2DU, at http://www.IAG.net/~w2du/quadfinal.pdf.
When installed pointing to the zenith, the "ideal,
theoretical" Quad Helix has 360 degree coverage in the azimuthal plane
and 90 degree coverage in the elevation plane. It is circularly
polarized over the entire upper hemisphere. There is no radiation in the
lower hemi-sphere; the energy in the lower hemi-sphere of an isotropic
radiator is uniformly distributed over the upper hemi-sphere. Hence the
gain of an "ideal" Quad Helix is 3.01 dBi. However you can modify the
elevation pattern to give more gain at the horizon and less gain
overhead by adjustment of the overall length to diameter ratio. It is
possible to adjust this ratio to give constant signal amplitude, at an
earth based receiving station, from a satellite in a circular orbit
where the range ratio (and hence signal path attenuation) between AOS
and the zenith can be significant. This results in a little radiation
below the horizon and also avoids the nasty mathematical boundary value
problem at the horizon in the ideal case.
Quadrifilar Helix antennas are used on many LEO
satellites for VHF, UHF, L-band and S-band communication. One of
their parameters of interest to satellite builders is that they do NOT
require a "ground plane" provided they are at least a quarter wavelength
above the satellite structure. Hence there is negligible critical
location requirement and they do not occupy satellite surface area that
is required for solar cells.
The Quadrifilar Helix antenna is popular with earth
based receiving stations for receiving the VHF image data signals from
the NOAA weather satellites. Right-hand circular Quad Helix antennas for
the 137MHz NOAA weather image signals and 137MHz left-hand circular Quad
Helix antennas for receiving the ARGOS programme signals, are available
from Spectrum International, Inc. Spectrum also supplies both right-hand
and left-hand versions for the 2M and 70cm Amateur radio bands.
May we suggest you sprinkle some "Grow More fertilizer"
around the base of your "chopped down satellite array" every Sunday
morning and offer a few words of wisdom while so doing. With a little
help and the dregs of Saturday night's Black and Tan, your mini array
might grow.
Regards, Spectrum.
_______________________________________________
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, 25 Aug 2010 19:28:20 +0200
From: "Gabriel - EA6VQ" <ea6vq_ml@xxxxx.xxxx>
Subject: [amsat-bb] Operation from IN70
To: <amsat-bb@xxxxx.xxx>
Message-ID: <7196721DFABF4F90A10132B511CE954F@xxx>
Content-Type: text/plain; charset="us-ascii"
A group of 4 operators will be operating as AO1EME from IN70qk on 2-5
september.
The main goal will be EME on 144 MHz, but we'll also have a 70cm. 20 el.
cross yagi and we'll be operating the satellite when there is no Moon and
time permits.
For more information, operation status, on-line logs, etc please visit
http://www.vhfdx.info/burguillo.html
73. Gabriel - EA6VQ
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Message: 15
Date: Wed, 25 Aug 2010 20:42:40 +0200
From: John Hackett <archie.hackett@xxxxxxx.xxx>
Subject: [amsat-bb] QSP
To: <amsat-bb@xxxxx.xxx>
Message-ID: <SNT104-W1ED42BC50DE688364928B91840@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
>From EA6VQ via LA2QAA.
A group of 4
operators will be operating as AO1EME from IN70qk on 2-5
september.
The main goal will
be EME on 144 MHz, but we'll also have a 70cm. 20 el. cross yagi and we'll be
operating the satellites when there is no
Moon and time permits.
For more
information, operation status, on-line logs, etc please visit
http://www.vhfdx.info/burguillo.html
73. Gabriel - EA6VQ
P.S: I'm having problems posting this information to
the Amsat-BB mailing list. Could someone please forward this info to that
list too?
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End of AMSAT-BB Digest, Vol 5, Issue 352
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