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CX2SA > SATDIG 31.05.13 15:52l 642 Lines 21742 Bytes #999 (0) @ WW
BID : AMSATBB8183
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Subj: AMSAT-BB-digest V8 183
Path: IZ3LSV<IK6ZDE<VE3UIL<JE7YGF<XE1FH<LU6PCK<CX2SA
Sent: 130531/1347Z @:CX2SA.SAL.URY.SA #:6899 [Salto] FBB7.00e $:AMSATBB8183
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. ANTELSAT a SSTV CubeSat from Uruguay (M5AKA)
2. Re: Is there anyway to get a linear transponder on the ISS?
(Michael)
3. Circular Polarization with Two Yagis (Spacing) (Mike Sprenger)
4. . Re: International Space Station-Bounce on 1296 MHz (i8cvs)
5. Re: Circular Polarization with Two Yagis (Spacing) (i8cvs)
6. Digipeating Through the ISS (Les Rayburn)
7. Subject: Is there anyway to get the transponder on the ISS
working again ? (K5VOU)
8. Grid trip to DN64, WY (Rodney Waln)
9. Re: Subject: Is there anyway to get the transponder on the
ISS working again ? (gordonjcp@xxxx.xxxx
10. Re: Circular Polarization with Two Yagis (Spacing)
(Jari Koivurinne)
11. Re: Is there anyway to get a linear transponder on the ISS?
(M5AKA)
12. Re: Is there anyway to get a linear transponder on the ISS?
(Raydel Abreu Espinet)
13. Re: Is there anyway to get a linear transponder on the ISS?
(PSK31) (Robert Bruninga)
14. Re: Is there anyway to get a linear transponder on the ISS?
(PSK31) (Raydel Abreu Espinet)
----------------------------------------------------------------------
Message: 1
Date: Thu, 30 May 2013 20:56:15 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] ANTELSAT a SSTV CubeSat from Uruguay
Message-ID:
<1369943775.93949.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Another CubeSat planning a Yasny Dnepr launch this year.
ANTELSAT has an AX.25 packet radio digipeater and a 70cm SSTV downlink.
See http://amsat-uk.org/2013/05/30/antelsat-sstv-cubesat/
----
73 Trevor M5AKA
AMSAT-UK website http://amsat-uk.org/
Facebook https://www.facebook.com/pages/AMSAT-UK/208113275898396
Twitter https://twitter.com/AMSAT_UK
----
------------------------------
Message: 2
Date: Thu, 30 May 2013 18:38:43 -0400
From: Michael <Mat_62@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Is there anyway to get a linear transponder on
the ISS?
Message-ID: <51A7D4F3.50907@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 5/30/2013 12:21 PM, gordonjcp@xxxx.xxx wrote:
> On Thu, May 30, 2013 at 11:02:15AM -0400, Robert Bruninga wrote:
>>> if there were a "real" ham on the ISS things would be different.
>> Yep, then nothing would get done. All he would do is float around and
>> complain about all the things that everyone else should be doing.
>>
> ... and moaning about how astronauts these days have it too easy, and it
wasn't like this twenty years ago, and if they had only kept the requirement
for astronauts to be fighter pilots we'd be on Mars now.
>
Don't forget that if they made the astronauts pass the code to get
their license it would instantly transform them into better operators.
Honestly this thread just points out to me how "self important" some
hams are. NASA has better things to do than worry about pleasing the
wants and whims of ham radio operators. We are extremely lucky we have
anything at all up there and should be thankful we have it rather than
whining about guitars and such!
73,
Michael, W4HIJ
------------------------------
Message: 3
Date: Thu, 30 May 2013 20:51:27 -0400
From: Mike Sprenger <mikesprenger@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Circular Polarization with Two Yagis (Spacing)
Message-ID:
<CAB4zG_+fDmSaDMtA=ZUQ=2+jvyBf9mOcjiovT7Qb+mRF=jBU6g@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi,
I'm sure this has been covered, I just can't find some detail.
I'd like to consider taking a pair of say 3, 5, or even 11 element 2M
yagi's (off the shelf) and put them on a boom on either side of a rotor,
with nonconductive cross support boom, rotating the boom's to offset the
elements 90 degrees.
Question I have, what would the spacing be between the two yagi's ?
Jerry has done this with success on 2 meters:
http://www.n0jy.org/images/IMG_20120623_215906.jpg
It would be great to refine his good work with the spacing for the 2 booms.
(Then I may compare with putting all the elements on one boom)
I like the collaborative nature of the discussion here.
--
Thanks,
Mike
------------------------------
Message: 4
Date: Fri, 31 May 2013 04:54:41 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
To: "Andreas Imse" <andreas@xxxx.xx>, <jari.koivurinne@xxxx.xxx>,
"Amsat - BBs" <amsat-bb@xxxxx.xxx>, "Ing. Pavel Milanes Costa"
<co7wt@xxxxxx.xx.xx>, "Trevor ." <m5aka@xxxxx.xx.xx>, "PA3FXB Jan van
Muijlwijk" <jvmmap@xxxx.xx>
Subject: [amsat-bb] . Re: International Space Station-Bounce on 1296
MHz
Message-ID: <000001ce5daa$56b44000$0401a8c0@xxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Von: i8cvs [mailto:domenico.i8cvs@xxx.xxx
Gesendet: Donnerstag, 30. Mai 2013 01:13
An: Andreas Imse
Betreff: Re: [amsat-bb] Re: International Space Station-Bounce on 1296 MHz
Wichtigkeit: Hoch
Hi Andreas, DJ5AR
Using the RADAR equation I would like to perform a link calculation of your
QSO with Jan PA3FXB through the International Space Station-Bounce on 1296
MHz
I already know that the gain of your 3 meter dish is 29 dB and your power at
the feed point is 200 W but I need the additional estimated following
informations:
1) The range and the elevation from the ISS and your QTH as soon you started
receiving your own ECHO'es signals.
2) The maximum range and the elevation from the ISS and your QTH when your
received signals were the strongest possible.
3) Were you receiving in analogic CW using 500 Hz filter and headphone or
were you using digital WSJT software such as FSK441 or others software
(commonly used for rapidly moving meteor scatter QSO's). ?
When the ISS is at the AOS with elevation of 2 degrees the range is about
2000 km and when the elevation is about 35 degrees the range is about 700 km
so that I plan to calculate the budged link for a range 700 km and see what
the results are in Signal to Noise ratio using only a analogic CW receiver
and
than calculate the advantages using a digital system.
Thanks for your answere.
73" de i8CVS Domenico
----- Original Message -----
From: Andreas Imse
To: domenico.i8cvs@xxx.xx
Sent: Tuesday, May 28, 2013 9:23 AM
Subject: [amsat-bb] Re: International Space Station-Bounce on 1296 MHz
Hi Domenico,
I saw your posting and will give you a short reply.
We are both using 3 m dishes, 200 W here and 375 W on Jan?s side.
That was far enough for our tests.
As our QTHs are quite close (only 367 km), it is possible that QSOs over a
larger distances might be possible with less power like in aircraft scatter.
If you are equipped for 1296 MHz and able to track the ISS with your
antenna, we should have a try.
Doppler compensation can be done completely on my side.
vy 73,
Andreas
DJ5AR / EI8HH
dj5ar@xxxx.xx
www.dj5ar.de
----- Original Message -----
From: "Andreas Imse" <andreas@xxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Sent: Thursday, May 30, 2013 10:20 AM
Subject: [amsat-bb] Re: International Space Station-Bounce on 1296 MHz
Hi Domenico and all others, interested in this subj
I am not looking for completing QSOs only and would like to test with
receiving stations too.
if you have an antenna for 1296 MHz and are able to do ISS tracking, we can
try.
I can perform the complete doppler compensation as well for uplink as for
downlink here.
So the receiving station may stay and listen on a fixed frequency ( e.g.
1296,300 MHz).
vy 73,
Andreas
DJ5AR / EI8HH
mailto:dj5ar@xxxx.xx> dj5ar@xxxx.xx
--------------------------------------------------------------------------
Hello Andreas, DJ5AR / EI8HH
Using the data of your station and that of Jan PA3FXB I was
able to compute the Link Budged calculations for the international
Space Station-Bounce on 1296 MHz
LINK BUDGED CALCULATIONS by i8CVS
We consider the ISS like a passive reflector with reflectivity
factor of 10 % to try a QSO by reflection Earth-ISS-Earth
DATA:
1) The solar panels of the ISS plus the central body large like a
Boeing 747 have a metallic reflecting surface of about
2000 square meters and we consider the ISS like a circular
RADAR target having being a metallic plate an estimated
reflectivity factor S of 10 % at SHF
2) The range EARTH-ISS at elevation of 35 degrees is about
700 km
3) Our EME station at 1296 MHz uses a 3 meters dish in diameter
with gain of 29 dB and 200 W at the feed
4) The overall noise figure of our receive system is NF = 0.5 dB
while the antenna temperature is 50 kelvin when pointed at the
Cold Sky and we receive on CW using a filter with a BW large
500 Hz
5) We use only analogic reception without digital software like
WSJT or similar tecniques.
CALCULATION PROCEDURE :
Aiming the dish towards the ISS when distant 700 km and
transmitting on CW and using the RADAR equation we
calculate the Signal to Noise ratio S/N to see if on CW the
echoes reflected by the ISS are above or belove the Noise
Floor of receiver.
First of all using the RADAR equation we calculate the round
trip attenuation in dB between EARTH-ISS-EARTH when
approaching to TCA the average range is 700 km
RADAR EQUATION
Pt x Gt x Ar x S
Pr = -----------------------------
( 4 x 3.14 x R^2 ) ^2
Where :
Pr = power received in watt
Pt = power transmitted = 1 watt
Gt = isotropic gain of a ground antenna at 1296 MHz = 1 time
in power or 0 dB
Ar = aperture area of isotropic antenna at 1296 MHz = 0,0043
square meters
S = Sigma or Radar Cross Section i.e. the surface of the ISS in
square meters with reflecting coefficient of 0.10 = 10 %
R = distance or range EARTH-ISS = 700 km = 700000 meters
NOTE:
(4 x 3.14 x R^2)^2 calculates the surface of a sphere having a
radius R=700000 meters elevated time 2 to take account of the
round trip "EARTH-ISS-EARTH"
CALCULATION OF ATTENUATION "EARTH-ISS-EARTH"
:
S = Sigma of the ISS with reflecting surface of 2000 square meters
and reflection coefficient of 10 % = 2000 x 0.10 = 200 square meters
Calculation of the aperture area Ar of isotropic antenna at 1296 MHz
/ 2 2
/\ 0,2314
Ar = ---------- = ----------- = 0,0043 square meters
4 x 3,14 4 x 3,14
Calculation of the received power Pr on the EARTH
collected by the isotropic antenna at 1296 MHz
1 x 1 x 0.0043 x 200 -26
Pr = ---Te of the receiver is
Te = ( F-1) x 290 = (1,12 -1) x 290 = 35 kelvin
The overall Noise Floor KTB of the receiving system with the
antenna connected is :
KTB = K x ( Te + Ta ) x BW and in numbars :
-23
Noise Floor KTB = 1,38 x 10 x ( 35 + 50 ) x 500 = -182.3 dBW
LINK CALCULATION "round trip" EARTH -ISS-EARTH at 1296 MHz
on CW
TX power at feed.................................+23 dBW = 200 watt
Antenna Gain in TX................. ...........+29 dBi
------------
EIRP transmitted to the ISS. ..............+52 dBW = 158.5 kW
Attenuation EARTH-ISS-EARTH... - 256.4 dB
-------------
Power Pr received on EARTH over
isotropic antenna ............................ - 204.4 dBW
Antenna Gain in RX......................... + 29 dB
------------
Power incident at receiver input ...... - 175.4 dBW
RX Noise Floor......................... ........- 182.3 dBW
------------
S/N ratio CW at RX audio output... + 6.9 dB
CONCLUSION :
At a range of 700 km from the ISS and using a 3 meters dish with
200 W at the feed and a receiving system with a Noise Floor of
-183.3 dBW = - 153.3 dBm it is possible to hear your hown echo
signals in plain analogic CW with a Signal to Noise ratio S/N of
+6.9 dB wich is very strong.
If two stations are equipped with the same equipments it is
possible to make good QSO for a short time when the ISS
is close range around 700 km at elevation of about 35
degrees.
Increasing the BW of receiver at 2700 Hz to try receive SSB
it is very difficult since the signal reflected back by the ISS
will be very noisy with a S/N ratio of about - 0.5 dB and so
belove the Noise Floor of your receiver.
It is necessary to use a precise traking system particularly fast
to move the dish as soon the ISS approach the TCA because
the beam wide of a 3 meter dish with gain of 29 dB is large
only about 5 degrees at the -3 dB points so that traking the
ISS at 1296 MHz with a 3 meter dish or even larger for EME
it seems to be the more critical point.
73" de
i8CVS Domenico
------------------------------
Message: 5
Date: Fri, 31 May 2013 06:23:04 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
To: "Mike Sprenger" <mikesprenger@xxxxx.xxx>, "Amsat - BBs"
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Circular Polarization with Two Yagis (Spacing)
Message-ID: <000001ce5db6$d025eae0$0401a8c0@xxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Mike,
I suggest you to mount the elements ove good pass of the
ISS over the Southeastern US.
It was really something to see the software display stations and plot
them on a map as the ISS passed
overhead. Even more so to see my own callsign digipeated through the
software.
Next up is to attempt a full fledged QSO through the ISS in real-time.
My special thanks to Joanne Maenpaa, K9JKM whose paper on working
through the ISS using software was
most helpful.
I used my Icom IC-910H with a Signalink interface instead of a hardware TNC.
Having a blast on the birds, and this just adds a whole other element of
fun to the process.
--
73,
Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf
6M VUCC #1712
AMSAT #38965
Grid Bandits #222
Southeastern VHF Society
Central States VHF Society Life Member
Six Club #2484
Active on 6 Meters thru 1296, 10GHz & Light
------------------------------
Message: 7
Date: Thu, 30 May 2013 21:08:24 -0500
From: K5VOU <k5vou2@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Subject: Is there anyway to get the transponder on
the ISS working again ?
Message-ID: <51A80618.7000303@xxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Let me summarize what I think was said in answer to my question; "Is
there any way to get a linear transponder on the ISS?"
1.) There is already a transponder on the ISS albeit an et=iso-8859-1
Hello All,
Here is Mak's excellent circular polarization page:
http://sv1bsx.50webs.com/antenna-pol/polarization.html
-jari oh3uw
------------------------------
Message: 11
Date: Fri, 31 May 2013 11:35:31 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: co7wt@xxxxxx.xx.xxx w7lrd@xxxxxxx.xxxx g0mrf@xxx.xxx
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Is there anyway to get a linear transponder on
the ISS?
Message-ID:
<1369996531.9492.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
--- On Thu, 30/5/13, g0mrf@xxx.xxx <g0mrf@xxx.xxx> wrote:
> Mode A has issues with higher noise levels and the size of
> antenna required on the satellite.
>
> But, I agree mode A would get a lot of interest from people
> with HF +
> 50MHz equipment.
> - HF antenna = prototype deorbit system??
> or 2 x ferrite rods at 90 degrees on receive
David, there is already an HF monopole (15-30 MHz) installed on the ISS has
been since the early days.
I gather there are antennas for HF, 144, 435 feeding into the Russian
Service Module and antennas for 144, 435, 1260 (2 antennas) and 2400 (two
antennas) feeding into the ESA Columbus Module.
Some info on the Russian Service Module antennas at
http://www.marexmg.org/hardware/antennas.html
73 Trevor M5AKA
------------------------------
Message: 12
Date: Fri, 31 May 2013 08:48:03 -0400 (CDT)
From: Raydel Abreu Espinet <cm2esp@xxxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Is there anyway to get a linear transponder on
the ISS?
Message-ID:
<19371974.1823451.1370004483451.JavaMail.root@xxxxxx.xx.xx>
Content-Type: text/plain; charset=utf-8
The nicest configuration for a system great and easy for everyone, including
both small low budget stations and pro stations would be a 2m FM uplink with
CTCSS to avoid interference and a SSB 10m downlink. It can be easily done
bypassing the audio output of one 2m radio used as receiver to a VOX
compatible SSB 10m radio for transmission.
Such configuration can allow stations from all over the world to enjoy
satellite comms even from those countries where modern high tech ham radio
equipments are scarce (my own country is on this list and it is not alone on
it) and yet provide a fun configuration for those pro and modern stations
wishing to remember the good old days from the 10m downlink satellites that
I have always heard about.
Regarding the "noise" and antenna difficulties of a 10m SSB downlink several
fellows hams mention on previous e-mails. I can tell this: I live in a
highly RF contaminated city, lots and lots of cheap poor shielded chinese
switching power supply units on DVD players and old rusty power electricity
aerial transmission linthe same as all our other FM satellites. Only a
single user at a time. Congestion, conflict and little practical value.
The better use of SSB is to use the same single channel FM bandwidth for a
wideband transponder allowing up to 30 or more simultaneous users. This
is equally trivial to do. Just connect the output of a 10m SSB receiver
tuned to 28.120 MHz to an FM downlink and use PSK-31 on the uplink. The
FM downlink gives everyone in the footprint the identical PSK waterfall
spectrum where they can tune all 30 QSO's simultaneously. Then each
person sets their PSK-31 uplink to an unused 100 Hz wide area in the
spectrum
Not only can 30 stations participate at once, the fact that they are
transmitting on 10m PSK31 and receiving on 2m or UHF FM at the same time
means they are also operating full duplex during the entire pass.
Everyone can talk to everyone without conflict or congestion.
And no special hardware is required for users. A PC with a sound card can
do it all.
Bob, WB4APR
------------------------------
Message: 14
Date: Fri, 31 May 2013 09:31:50 -0400 (CDT)
From: Raydel Abreu Espinet <cm2esp@xxxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Is there anyway to get a linear transponder on
the ISS? (PSK31)
Message-ID:
<26584517.1825588.1370007110484.JavaMail.root@xxxxxx.xx.xx>
Content-Type: text/plain; charset=utf-8
Hi Bob,
Yes I remember reading about your proposal few months ago and I think it is
a nice idea. Even with user collaboration it can be shared both digital and
voice communication. If the digital signals are on the 200 ~~ 500 Hz section
of the pass band and the voice in 600 ~~ 3 KHz (it would not sound perfect,
but yet understandable) So the system is also versatile.
I always try to keep voice on mind because in all over the world there will
be always someone who prefer voice over different modes, it is a big crowded
planet. So with shared channel, user collaboration and patience it can be
done.
It would not had 30 users simultaneously, but perhaps up to 5 or 6? Users
should respect frequency plan and accept the digi or voice sounds in both
cases that may be annoying but it could "theoretically" work also.
Just thinking how to keep everyone happy is a hard work, but not impossible!!!
73,
Raydel, CM2ESP
----- Mensaje original -----
De: Robert Bruninga <bruninga@xxxx.xxx>
Para: amsat-bb@xxxxx.xxx
Enviado: Fri, 31 May 2013 09:04:33 -0400 (CDT)
Asunto: [amsat-bb] Re: Is there anyway to get a linear transponder on the
ISS? (PSK31)
> The nicest configuration... would be a 2m FM uplink with CTCSS to avoid
interference and a SSB 10m downlink.
The problem with that is the same as all our other FM satellites. Only a
single user at a time. Congestion, conflict and little practical value.
The better use of SSB is to use the same single channel FM bandwidth for a
wideband transponder allowing up to 30 or more simultaneous users. This
is equally trivial to do. Just connect the output of a 10m SSB receiver
tuned to 28.120 MHz to an FM downlink and use PSK-31 on the uplink. The
FM downlink gives everyone in the footprint the identical PSK waterfall
spectrum where they can tune all 30 QSO's simultaneously. Then each
person sets their PSK-31 uplink to an unused 100 Hz wide area in the
spectrum
Not only can 30 stations participate at once, the fact that they are
transmitting on 10m PSK31 and receiving on 2m or UHF FM at the same time
means they are also operating full duplex during the entire pass.
Everyone can talk to everyone without conflict or congestion.
And no special hardware is required for users. A PC with a sound card can
do it all.
Bob, WB4APR
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_______________________________________________
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!
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End of AMSAT-BB Digest, Vol 8, Issue 183
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