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CX2SA > SATDIG 25.04.09 21:08l 301 Lines 9947 Bytes #999 (0) @ WW
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Today's Topics:
1. Re: Web space (Joe)
2. Re: AO-51 U/S (Shamai "SAM" Opfer)
3. AO-51 S band reception (Luc Leblanc)
4. DSTAR vs AO-51 (Luc Leblanc)
5. Re: FLTSATCOM Hacked (RFI-EMI-GUY)
----------------------------------------------------------------------
Message: 1
Date: Sat, 25 Apr 2009 09:39:42 -0500
From: Joe <nss@xxx.xxx>
Subject: [amsat-bb] Re: Web space
To: "Rich Dailey (gmail)" <redailey1@xxxxx.xxx>, amsat-bb@xxxxx.xxx
Message-ID: <49F320AE.8020907@xxx.xxx>
Content-Type: text/plain; charset=us-ascii; format=flowed
and i don't know for sure if it still does it, but Internet explorer
could in the past work just like a FTP program also.
Joe
Rich Dailey (gmail) wrote:
>>As others have noted, every major operating system out there has an FTP
client, but apparently that's not all that's required. What sort of error or
denial message are you getting? That will guide the next step.
>>
>>
>
>And don't forget about the command line client that's available in any WinXP
dos box.
>Tedious, but it works in a pinch.
>
>Rich, N8UX
>
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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>
>
>
------------------------------
Message: 2
Date: Sat, 25 Apr 2009 02:07:25 +0300
From: "Shamai \"SAM\" Opfer" <4z1ws.sam@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-51 U/S
To: w7lrd@xxxxxxx.xxx
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<e0a093a90904241607u7db37e03ya8e3ca0ae3c104e9@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi Bob
According to the schedule published by the ECHO command team, this week AO51
is operating V/S, not U/S. ( http://www.amsat.org/amsat-new/echo/CTNews.php
).
Am I missing anything?...
73
Shamai
4Z1WS
On Fri, Apr 24, 2009 at 6:59 PM, <w7lrd@xxxxxxx.xxx> wrote:
>
>
> At 1707Z, (next pass) I will be looking for W. coast US & Canada, KL7 for
> anyone with U/S capability.
>
> 73 Bob W7LRD
>
>
> _______________________________________________
> 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
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------------------------------
Message: 3
Date: Sat, 25 Apr 2009 07:01:08 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] AO-51 S band reception
To: amsat-bb@xxxxx.xxx
Message-ID: <49F2B534.4510.38D39B@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
On the current AO-51 S band downlink i notice the "always" present deep fades
period during a pass as the S band antenna are Dual band L/S
Open Sleeve (1/4 wave stub) it confirm why my actual linear "WI-FI" stacked
yagi perform better than my BBQ grill and dish with circular
polarisation.
Foliage and blocking structures "seems" to have a lesser effect on the yagi
than on the circular polarisation antenna. On one QSO with
Clare VE3NPC we noted that theses fades does not happen at the same time at
our respective QTH (Ottawa and Sorel-Tracy) making the
following excerpt quite accurate.
>From down to earth web site: http://www.docstoc.com/docs/5178447/down-to-
earth
Satellite antennas are usually whips or dipoles. The satellite may slowly
tumble, changing the orientation
of the antennas. If you happen to be "off the end" of its antenna, the signal
may be too weak to work. Even
if you remain out of its "null", the direction of the linear polarization of
the satellite downlink signal
changes relative to you during the pass. If the polarization at some instant
happens to be perpendicular to
the polarization of your receiving antenna, there is about a 20dB (100x)
signal loss.
I think i will give up in the fades elimination fight 100X signal is nearly
impossible to compensate at the receiving side. It is probably
an AO-51 S band limitation. Could be the internet can be a solution if each
station can feed their downlink audio on Skype or echolink it
will be possible to listen on theses various downlink sources making possible
to have a full pass reception as there will be always one
receiving station out of the fades.
DSTAR on S mode
As the first DSTAR satellite transmission has been made on AO-27 i don't know
if the same test can be perform on AO-51. If someone with
DSTAR capabilities is interesting to "test" it on mode V/S just let me know.
Why on mode V/S it's because i will have to be in half duplex
as my DSTAR transceiver is a monobander. It is a very "dangerous experiment"
here as i will have to manually TR switching between the VHF
antenna and the downconverter line.
But it will be interesting to know if a DSTAR digital signal can passed
through AO-51 first? I can try to send a couple of CQ on the last
mode V/S evening pass listening what goes out too?
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 4
Date: Sat, 25 Apr 2009 08:30:26 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] DSTAR vs AO-51
To: amsat-bb@xxxxx.xxx
Message-ID: <49F2CA22.12057.8A978D@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
As my first test this morning it appears digital DSTAR pass through but unable
to confirm if they will be decoded correctly as i am not in
full duplex?
Did anyone with DSTAR capabilities can send some CQ on the uplink or listen on
the S downlink to see if something can be decoded?
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 5
Date: Sat, 25 Apr 2009 13:49:31 -0400
From: RFI-EMI-GUY <Rhyolite@xxxxxxxx.xxx>
Subject: [amsat-bb] Re: FLTSATCOM Hacked
To: amsat-bb@xxxxx.xxx
Message-ID: <49F34D2B.1040500@xxxxxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
You don't give any credit to our international ham's for policing their own. I
am sure if Brazilian hams knew of a "pirate" on their own soil and were armed
with Lat Lon of the station, there would be action taken.
Secondly; all the encryption in the world is not going to protect the
satellite from jamming by some miscreant or an accidental source.
Personally when it gets to a point where to operate ham radio requires an RSA
key, a digital mode and a VPN, I will lose total interest. There is no
experimentation in that. I might as well log into my work e-mail which
requires "an RSA key, a digital mode and a VPN". The AMSAT group is reluctant
to pay for a launch opportunity let alone fancy authentication infrastructure.
For the folks developing "bent pipe transponders" such as PE1RAH, I say press
on, and make them as cheap and small as possible.
On Fri, 24 Apr 2009 15:54:54 -0400, "RFI-EMI-GUY"
<Rhyolite@xxxxxxxx.xxx> said:
> > I think it is less important to worry about technology that can't be
> > hacked and more important to devise a scheme to locate the source of
an
> > interferer be it deliberate or accidental. With a bent pipe
transponder
> > scheme, if there are two or more satellites having overlapping
> > footprint, you can monitor the downlink of each satellite and derive
a
> > time of arrival fix from each. Do some trig and get a fix on the
> > possible locations. I am sure this is exactly what the DOD is doing to
> > locate these pirates.
>
That leads logically to the next question -- what are you going to do
when you find them? Do you expect International government support to
send resources out to the location and shut down the offending station?
How much are you (and the rest of the world) willing to pay for this?
Better to lock the front door of the house, than to have to go wandering
the rooms, listening for the yahoos that came in the back door and are
eating your potato chips up in your kid's bedroom.
As it becomes easier for the general public to get their hands on uplink
gear cheaply, and to operate it with virtually zero knowledge of how it
actually works -- the front-end of the birds must have a way to
discriminate between "authorized" and "unauthorized" users...
eventually.
On-orbit infrastructure is too valuable to have it act as a "bent-pipe"
in an environment where the uplink/downlink gear is easy to acquire and
use.
See previous note on possible uses of encryption technology along with
decentralized authentication data... and more importantly, how much we'd
be willing to pay for such authentication infrastructure... in our time
to set it up, and in real money to have it accessible via the Net to
all. Not cheap, but then again -- real security never is.
Nate WY0X
--
Nate Duehr
nate@xxxxxxxx.xxx
--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"?
"Use only Genuine Interocitor Parts" Tom Servo ;-P
------------------------------
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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 4, Issue 199
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