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CX2SA > SATDIG 26.08.10 21:10l 378 Lines 12729 Bytes #999 (0) @ WW
BID : AMSATBB5354
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Subj: AMSAT-BB-digest V5 354
Path: IZ3LSV<IW0QNL<VE2PKT<F1BBI<CX2SA
Sent: 100826/1904Z @:CX2SA.LAV.URY.SA #:16006 [Minas] FBB7.00e $:AMSATBB5354
From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: SO-50 (Matt Patterson)
2. Re: New Satellite Downlink? (Robert Bruninga)
3. Re: Circular Polarized Antennae (i8cvs)
4. FS: Kenwood TT2000 HF/VHF/UHF satellite radio (John Geiger)
5. Re: SO-50 (Ng, Peter)
6. Re: New Satellite Downlink? (Drawing) (Robert Bruninga)
7. Re: SO-50 (Sebastian)
----------------------------------------------------------------------
Message: 1
Date: Thu, 26 Aug 2010 06:31:48 -0500
From: "Matt Patterson" <mattpatt@xxxxxxxx.xxx>
Subject: [amsat-bb] Re: SO-50
To: <amsAT-BB@xxxxx.xxx>
Message-ID: <001e01cb4512$458c46a0$d0a4d3e0$@xxx>
Content-Type: text/plain; charset="us-ascii"
That's true but you would think there would be others on the bird.
73 Matt
W5LL
-----Original Message-----
From: Rick Tejera [mailto:saguaroastro@xxx.xxxx
Sent: Wednesday, August 25, 2010 11:33 PM
To: 'Matt Patterson'
Subject: RE: [amsat-bb] SO-50
Matt,
Did you transmit the ON tone? SO-50 is set up so you have to turn it on by
transmitting on 145.85 with a PL of 74.4 hz for 2 seconds. This turns it on
for 10 minutes (if I recall correctly). Once it's on you transmit on 145.850
with a 67.0hz PL.
Clear Skies
Rick Tejera
Editor SACnews,
Public Outreach Coordinator
Saguaro Astronomy Club
Phoenix, Arizona
www.saguaroastro.org
saguaroastro@xxx.xxx
K7TEJ
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Matt Patterson
Sent: Wednesday, August 25, 2010 21:09
To: amsAT-BB@xxxxx.xxx
Subject: [amsat-bb] SO-50
Was listening for the SO-50 pass @ 22:58Z and didn't hear anything. A check
of the Oscar status website reveals that it was active a couple hours ago.
Did anyone else hear it during the latest pass? I finally got setup to
start recording the birds with my computer and was going to use SO-50 as a
test.
73 Matt
W5LL
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------------------------------
Message: 2
Date: Thu, 26 Aug 2010 08:39:06 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] Re: New Satellite Downlink?
To: <amsat-bb@xxxxx.xxx>
Message-ID: <C84EC7D7B1194A61A21126393E53AD20@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
> Transits #23 and #25. object nos 19070 and 19419.
Here is a possible application based on the unique nature of the
"navigation" message which is 26 lines of 6 words with each
being 39 bits. But the first 8 lines are changed every 2
minutes by inserting a new line and scrolling off the oldest
one. We can use this for a list of callsigns.
We can get a callsign and extra 8 bit authorization ID into the
39 bits, or 6 calls per line for a total of 48 calls. Then the
remaining 18 lines are available for what I call Quarter-Tweet
messages of 35 bytes each. We will also reserve a few lines for
special bulletins.
So here is how it would work.
1) User initiates a login request via internet to the command
station.
2) His call is added to the Login list on the satellite plus an
authorization byte
3) As noted above, this list scrolls down and only the last 48
are visible
4) Next he has to tune in the downlink to see his authorization
byte.
5) Now with his authorization byte, he can send a Q-tweet via
the internet
6) Which now shows up with 18 other Q-tweets in the remaining 18
lines downlink
Your Qtweet can contain a call to another station and when he
responds, you can count a QSO.
Something like that. The above idea lets everyone play, but
requires that they can hear the satllite first (like any other
satelite) before then can send an uplink (via the internet) for
reception (downlink) via RF.
We will use a 5 bit code (like RTTY) but will replace the CR and
LF with the "." and a CAPS shift. SO the 31 possible characters
are a-z plus "." plus CAPS, FIGS and LTRS. This allows normal
mixed case text...
Bob, WB4APR
------------------------------
Message: 3
Date: Thu, 26 Aug 2010 15:42:45 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: Circular Polarized Antennae
To: "Spectrum International, Inc" <spectrum.ma.ultranet@xxx.xxx>,
"John Hackett_LA2QAA" <archie.hackett@xxxxxxx.xxx>
Cc: la2qaa@xxxxx.xxxx AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <001501cb4524$9105b280$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Spectrum International, Inc" <spectrum.ma.ultranet@xxx.xxx>
To: "John Hackett_LA2QAA" <archie.hackett@xxxxxxx.xxx>
Cc: <la2qaa@xxxxx.xxx>; "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Sent: Wednesday, August 25, 2010 4:49 PM
Subject: [amsat-bb] Circular Polarized Antennae
< Snip >
> 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.
>
> Regards, Spectrum.
Hi Spectrum International,Inc
What you stated is absolutely correct and in my opinion the best
comprehensive article written over the Quadrifilar Helix Antennas by
Walter Maxell W2DU in his book "REFLECTIONS Transmission Lines
and Antennas" is the following one:
http://w2du.com/r2ch22.pdf
Best 73" de
i8CVS Domenico
------------------------------
Message: 4
Date: Thu, 26 Aug 2010 08:36:24 -0700 (PDT)
From: John Geiger <aa5jg@xxxxx.xxx>
Subject: [amsat-bb] FS: Kenwood TT2000 HF/VHF/UHF satellite radio
To: amsat-bb@xxxxx.xxx
Message-ID: <147186.32332.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
I have for sale or trade a 2008 model Kenwood TS2000 that does 100 watts on
HF, 6m, and 2m, and 50 watts on 70cm. I bought this radio used from Ham
Radio Outlet at the beginning of June, so it has been checked out recently
and found to work perfectly. Really like it but life things come up and I
need to downsize the shack a bit.
This radio has IF DSP so no optional filters are needed. It also has full
duplex for the satellites, a built in TCXO, a 2m/70cm subreceiver for
listening to the local repeaters while operating on the main receiver, and a
built in TNC. It will also do crossband repeat so you can get on HF or 6m
while walking around town with an HT-what a neat feature!
It is in very good condition with a couple of light scratches on the top of
the case (I doubt they would show up in a picture). It comes with the hand
mic, power cord, and manual. I think I still have the original box but it
is missing the stryofoam inserts,
though.
I am asking $1000 for it plus shipping, but can also meet for an inperson
deal in the Southwest Oklahoma/OKC/North Texas area. You will not be
disappointed with this radio-it does it all and does it all
pretty well.
73s John AA5JG
Lawton, OK
------------------------------
Message: 5
Date: Thu, 26 Aug 2010 10:06:10 -0700
From: "Ng, Peter" <Peter.Ng@xxxxx.xx>
Subject: [amsat-bb] Re: SO-50
To: Matt Patterson <mattpatt@xxxxxxxx.xxx>, "amsAT-BB@xxxxx.xxxx
<amsAT-BB@xxxxx.xxx>
Message-ID:
<44D6D682B38A5D4FAA2DBDE4AFD3B87D02951CFD@xxxxxxxx.xxxxxx.xxxxxx.xx>
Content-Type: text/plain; charset="us-ascii"
I was also surprised at how quiet SO-50 was during my initial attempts. I
thought there something wrong with my setup. I find the traffic on SO-50 is
very light. Don't know why...could be the time of day (or night in my
case). I had great help from KC2WQW and W6ZKH. Regardless of anyone else
being on, when you can hear myself on the downlink, you know you're getting
through. have fun!
73's Peter VE7NGP
>That's true but you would think there would be others on the bird.
>
>73 Matt
>W5LL
>>...
>>Did you transmit the ON tone? SO-50 is set up so you have to turn it on by
>>...
>>Rick Tejera
------------------------------
Message: 6
Date: Thu, 26 Aug 2010 14:52:23 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] Re: New Satellite Downlink? (Drawing)
To: <amsat-bb@xxxxx.xxx>
Message-ID: <B30F6310310A44E6B9A7C96593C4E32F@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Here is more info on how we could use the Navigation message of
these old satellites for a rudimentary satellite Q-Tweet system.
That is, you can send "Quarter-Tweets" for inclusion in the
downlink... But only after you have scheduled a login and
obtained (in the next downlink) your authorization code... See
the drawing:
http://aprs.org/transit/call-encoding.GIF
Using the scenario below:
Bob, Wb4APR
> -----Original Message-----
> On Behalf Of Robert Bruninga
> Sent: Thursday, August 26, 2010 8:39 AM
> Subject: [amsat-bb] Re: New Satellite Downlink?
>
>> Transits #23 and #25. object nos 19070 and 19419.
>
> Here is a possible application based on the unique
> nature of the "navigation" message which is 26 lines
> of 6 words with each being 39 bits. But one word in
> each of the first 8 lines are changed every 2 minutes
> by inserting a new word and scrolling off the oldest
> one. We can use this for a list of callsigns.
>
> We can get a callsign and extra 8 bit authorization
> ID into each of the 39 bit words. Then the rest of
> thos first 6 lines can be older callsigns and then
> the remaining 18 lines are available for what I call
> Quarter-Tweet messages of 35 bytes each. We will
> also reserve a few lines for special bulletins.
>
> So here is how it would work.
>
> 1) User initiates a login request via internet to
> the command station.
>
> 2) His call is added to the Login list on the
> satellite plus an authorization byte
>
> 3) As noted above, this list scrolls down and only
> the last 48 are visible
>
> 4) Next he has to tune in the downlink to: SO-50
To: amsat-bb@xxxxx.xxx
Message-ID: <09356F69-8AF4-4419-A912-0C89772FBF6D@xxxxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
SO-50 is generally quiet during the day for a few reasons. Many people are
at work, and it's also a weak bird that is not as easy to hear as AO-51. It
also requires a PL to turn it on if it's off, and then another PL to use it.
Also many satellite enthusiasts use the TS-2000 which has a birdie on the
downlink which can make it difficult, if not impossible to hear.
But it's a great bird with excellent audio.
73 de W4AS
On Aug 26, 2010, at 1:06 PM, Ng, Peter wrote:
> I was also surprised at how quiet SO-50 was during my initial attempts. I
thought there something wrong with my setup. I find the traffic on SO-50 is
very light. Don't know why...could be the time of day (or night in my
case). I had great help from KC2WQW and W6ZKH. Regardless of anyone else
being on, when you can hear myself on the downlink, you know you're getting
through. have fun!
>
> 73's Peter VE7NGP
>
>> That's true but you would think there would be others on the bird.
>>
>> 73 Matt
>> W5LL
>>> ...
>>> Did you transmit the ON tone? SO-50 is set up so you have to turn it on by
>>> ...
>>> Rick Tejera
------------------------------
_______________________________________________
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 354
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