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CX2SA > SATDIG 17.10.08 16:36l 653 Lines 19956 Bytes #999 (0) @ WW
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Today's Topics:
1. Re: SSTV Algorithms? (John B. Stephensen)
2. New Batteries on the ISS (Simon (HB9DRV))
3. SSTV on over UK (David Barber)
4. ISS on voice over UK, 1106UTC (Gordon JC Pearce MM3YEQ)
5. Re: ISS on voice over UK, 1106UTC (GW1FKY(AT)aol.com)
6. Re: [sarex] tx time (Dave Taylor)
7. ISS SSTV (Luc Leblanc)
8. ISS pass: 0731-0741 UTC ( Carlos E. Nu?ez LU9JX )
9. KLM polarity switch schematic (Angelo Friend)
10. ISS Contact (Rick - WA4NVM)
11. Re: SSTV Algorithms? (Curt Nixon)
12. Re: ISS Contact (Alan P. Biddle)
13. Re: SSTV Algorithms? (Simon (HB9DRV))
14. Re: SSTV Algorithms? (Nigel Gunn G8IFF/W8IFF)
15. Re: ISS recording Oct 16th 1338UTC (Ben Jackson)
16. ISS image yesterday (santanaamt(AT)aol.com)
17. Re: New Batteries on the ISS, Its solar (MM)
18. Re: SSTV Algorithms? (Curt Nixon)
19. ISS (Mr Jeffrey L Ross)
20. Re: ISS (Simon (HB9DRV))
----------------------------------------------------------------------
Message: 1
Date: Fri, 17 Oct 2008 09:18:27 -0000
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Subject: [amsat-bb] Re: SSTV Algorithms?
To: "Gordon JC Pearce MM3YEQ" <gordonjcp(AT)gjcp.net>,
<amsat-bb(AT)amsat.org>
Message-ID: <3500D6881DE846BC984998D1F9EB0730(AT)your6bvpxyztoq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
The filtering ensures that the shape is known. A triangle wave above half
the cutoff frequency becomes a sine wave as filtering removes the harmonics.
73
John
KD6OZH
>
> Hmm. That's not quite true. Consider a signal at 4kHz, being sampled
> at 8kHz. What you'd see is a triangle wave, if you were sampling at the
> peaks of the incoming signal (if you were sampling at the crossover
> points, you'd see no signal at all!). How do you tell what the waveform
> of the signal originally was? You can't...
>
> If you sample your 4kHz signal at 16kHz, you've got four points across
> each cycle, so at least you can start to get an approximation. If the
> input signal was a sinewave you might see a sample at a crossing point,
> then a sample at a peak, then a sample at the next crossing point, then
> a sample at the next peak. You'd get a roughly sinewave-y signal, if
> you squint a bit.
------------------------------
Message: 2
Date: Fri, 17 Oct 2008 11:38:52 +0200
From: "Simon \(HB9DRV\)" <simon(AT)hb9drv.ch>
Subject: [amsat-bb] New Batteries on the ISS
To: "AMSAT.org" <amsat-bb(AT)amsat.org>
Message-ID: <9E98529CA1614B2A99F22731ED310475(AT)doubletrouble>
Content-Type: text/plain; charset="iso-8859-1"
Pics being sent:
http://www.ham-radio-deluxe.com/SSTV/tabid/85/Default.aspx
Simon Brown, HB9DRV
www.ham-radio-deluxe.com
------------------------------
Message: 3
Date: Fri, 17 Oct 2008 10:44:09 +0100
From: "David Barber" <david.barber(AT)dbelectronics.co.uk>
Subject: [amsat-bb] SSTV on over UK
To: <sarex(AT)amsat.org>, <amsat-bb(AT)amsat.org>
Message-ID: <5F2F055C12014CFFBB2EB2E403D569F6(AT)DBXPPPOR>
Content-Type: text/plain; charset="us-ascii"
SSTV on over UK.
Long silent carrier before and after images though.
------------------------------
Message: 4
Date: Fri, 17 Oct 2008 12:19:06 +0100
From: Gordon JC Pearce MM3YEQ <gordonjcp(AT)gjcp.net>
Subject: [amsat-bb] ISS on voice over UK, 1106UTC
To: amsat-bb(AT)amsat.org
Message-ID: <48F874AA.6070703(AT)gjcp.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I caught quite a lot of this pass this afternoon, again with just the
omni and the old Trio.
http://www.gjcp.net/~gordonjcp/friday1106.ogg
Seems to be Richard talking to a group of school pupils.
Gordon MM3YEQ
------------------------------
Message: 5
Date: Fri, 17 Oct 2008 07:28:11 EDT
From: GW1FKY(AT)aol.com
Subject: [amsat-bb] Re: ISS on voice over UK, 1106UTC
To: gordonjcp(AT)gjcp.net, amsat-bb(AT)amsat.org
Message-ID: <be3.2f8214c5.3629d0cb(AT)aol.com>
Content-Type: text/plain; charset="US-ASCII"
Hi Yes,
Excellent copy hear in Wales on a HT -It was a link up with Budbrooke
Primary School in Warwick in the UK.
The video streaming also went very well - Congratulations to all of the team
and the support given by all.
The feedback from the video streaming text messages show how much the link
up was appreciated.
Ken
GW1FKY
Amsat -UK
Amsat NA
------------------------------
Message: 6
Date: Fri, 17 Oct 2008 07:42:12 -0400
From: Dave Taylor <dave.w8aas(AT)verizon.net>
Subject: [amsat-bb] Re: [sarex] tx time
To: amsat-bb(AT)amsat.org
Message-ID: <3BB806ED-DA6A-4215-8AE1-B2A4ABB98777(AT)verizon.net>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
The delay between automatic transmissions is fixed at 3 minutes.
That's built into the VC-H1.
-- Dave, W8AAS
On Oct 17, 2008, at 7:03 AM, amsat wrote:
> Hi all,
> Again i received a nice sstv image. orbit 56775.
> Like SM5SRR Eskil posted, You have to be lucky to receive due to the
> tx
> hang time when iss is not on a overhead pass.
> I wonder what happens after Richard leaves the iss. if the sstv stay's
> on, leave it like it is. then we would have much opportunities to
> receive sstv.
> If sstv would not be on all the time or we have to wait as long as we
> did now, maybe someone would set the hang time a little shorter...
>
> Tnx to all the people who have helped to setup this project.
>
> Grtz Ward
>
> ----
> Sent via sarex(AT)amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite
> program!
> Subscription settings: http://amsat.org/mailman/listinfo/sarex
------------------------------
Message: 7
Date: Thu, 16 Oct 2008 14:52:39 -0400
From: Luc Leblanc <lucleblanc6(AT)videotron.ca>
Subject: [amsat-bb] ISS SSTV
To: amsat-bb(AT)AMSAT.Org
Message-ID: <48F75537.10619.66BBDF9(AT)lucleblanc6.videotron.ca>
Content-Type: text/plain; charset=US-ASCII
On the 1833 pass the only one picture transmited where a variant of the BSOD
(Blue Screen Of Death)
with the NA1SS call sign
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 8
Date: Fri, 17 Oct 2008 04:52:10 -0300
From: " Carlos E. Nu?ez LU9JX " <lu9jx(AT)arnet.com.ar>
Subject: [amsat-bb] ISS pass: 0731-0741 UTC
To: <amsat-bb(AT)amsat.org>
Message-ID: <C5BBDC51A4BC4ABF8F477032DE25DCFB(AT)LU9JX>
Content-Type: text/plain; charset="iso-8859-1"
ISS pass 0731-0741 UTC (max elevation 83?!): nothing (144800 and 144825 kHz).
Lalo LU9JX GF19af
------------------------------
Message: 9
Date: Fri, 17 Oct 2008 06:59:57 -0500
From: "Angelo Friend" <n5uxt(AT)email.com>
Subject: [amsat-bb] KLM polarity switch schematic
To: amsat-bb(AT)amsat.org
Message-ID: <20081017120000.269FB47808F(AT)ws1-5.us4.outblaze.com>
Content-Type: text/plain; charset="iso-8859-1"
I just took down my polarity switch for my 2 meter KLM and I need to do
some work with it. I just receivedthe new relay to install but I may have
damaged a trace or two. So anyone have pictures (without reply
installed) or schematic of the board itself??? Thanks in advance. 73 de
Angelo
--
Be Yourself (AT) mail.com!
Choose From 200+ Email Addresses
Get a Free Account at www.mail.com
------------------------------
Message: 10
Date: Fri, 17 Oct 2008 07:41:57 -0500
From: "Rick - WA4NVM" <wa4nvm(AT)comcast.net>
Subject: [amsat-bb] ISS Contact
To: "AMSAT BB" <amsat-bb(AT)amsat.org>, <wa4sca(AT)amsat.org>
Message-ID: <0b2901c93055$be6986b0$6400a8c0(AT)HamRadioRoom>
Content-Type: text/plain; charset="iso-8859-1"
Hi Alan & fellow AMSAT,
Congrats on your contact with Richard on the ISS! I heard him return your
call.
Maybe some more of us will snag him before he goes home.
73, Rick - LM1339
------------------------------
Message: 11
Date: Fri, 17 Oct 2008 08:52:26 -0400
From: Curt Nixon <cptcurt(AT)flash.net>
Subject: [amsat-bb] Re: SSTV Algorithms?
To: amsat-bb(AT)amsat.org
Message-ID: <48F88A8A.4030706(AT)flash.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Joe:
I beg to differ with you on the sampling information. Having been a
digital signal acquisition and instrumentation specialist for a number
of years, I'm quite familiar with the nyquist criteria and all.
Sampling at 2f, you know the frequency and something about amplitude of
the signal and thats about all. That stuff about knowing ALL about it
is just not true--"if" you knew ahead of time, that the signal in
question was nothing but sinusoidal, then yes, you are correct--but how
often is that the case. That is what has driven highly oversampled AD
conversion. If you meant twice the maximum frequency COMPONENT of the
signal, then thats close, but is still based upon sin theory (fourier
series) and leaves alot of detail out of non-sinusoidal parts of the
signal unless one considers all of the harmonic content of the source.
For investigative or diagnostic work, especially characterizing
waveshape leading edges of clocks, etc, we used to recommend sample
rates of 5-8 times the highest frequency component of interest.
I wasn't so interested in the actual SSTV algorithms as I was in seeing
if there is any visible difference in the result of different algorithm
use--or is everyone using the same decoding kernel?
Thank you Sir, I suspect you know all this anyway--thought I would
clarify it as I came to understand it.
Curt
KU8L
Joe Fitzgerald wrote:
> Curt Nixon wrote:
>> I expect that the faster the soundcard samples, the better?
>>
>>
> It's counterintuitive, but through the magic of sampling theory, once
> you sample at twice the maximum frequency of the signal you are
> interested in you know _everything_ about it! As a practical matter,
> most ham gear audio rolls off sharply above 3 kHz (and SSTV is lower
> than that) , so sampling at a measly 8 or 11.025kHz rate is plenty.
> Howard Long wrote:
>> Do you know of detailed texts that are public domain? If
>> so let's have 'em!
>>
>>
>
> And it's not public domain, but it is available as free software:
> check out QSSTV for source code.
>
> If you are interested in sampling theory, check out
> http://www.dspguide.com/ch3/2.htm
>
> -Joe KM1P
>
------------------------------
Message: 12
Date: Fri, 17 Oct 2008 08:13:38 -0500
From: "Alan P. Biddle" <APBIDDLE(AT)UNITED.NET>
Subject: [amsat-bb] Re: ISS Contact
To: "'Rick - WA4NVM'" <wa4nvm(AT)comcast.net>, "'AMSAT BB'"
<amsat-bb(AT)amsat.org>
Message-ID: <EE0F0ECF3C71467FA77AE42D24907C63(AT)WA4SCA>
Content-Type: text/plain; charset="us-ascii"
Rick,
Thanks for the "QSL" on my contact. I already have the card filled out, in
the envelop, with SASE. I QSL 100% received, but this is the first one I
have sent out unsolicited in 10-15 years.
Alan
WA4SCA
------------------------------
Message: 13
Date: Fri, 17 Oct 2008 15:20:33 +0200
From: "Simon \(HB9DRV\)" <simon(AT)hb9drv.ch>
Subject: [amsat-bb] Re: SSTV Algorithms?
To: "Curt Nixon" <cptcurt(AT)flash.net>, <amsat-bb(AT)amsat.org>
Message-ID: <EDCB26CB0C0A4656A28340509F0C8A01(AT)doubletrouble>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi,
Briefly - the SSTV developers have their own algorithms more-or-less, what
we are mostly interested in is the frequency at a point in time. Simplifying
things further - we need to know frequency for each point in the line, the
filtering we use to pre-process the incoming signal removes noise etc. After
all - it's an analogue specification.
There would be no advantage to sampling at 48kHz instead of 8kHz, in fact it
would use a lot more CPU to run the filters.
The filtering we use is very standard stuff, SSTV is a nice and simple
concept, the big problem is combating noise, fading and multi-path
interference.
Simon Brown, HB9DRV
www.ham-radio-deluxe.com
----- Original Message -----
From: "Curt Nixon" <cptcurt(AT)flash.net>
>
> I wasn't so interested in the actual SSTV algorithms as I was in seeing
> if there is any visible difference in the result of different algorithm
> use--or is everyone using the same decoding kernel?
>
------------------------------
Message: 14
Date: Fri, 17 Oct 2008 13:22:49 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel(AT)ngunn.net>
Subject: [amsat-bb] Re: SSTV Algorithms?
To: amsat-bb(AT)amsat.org
Message-ID: <48F891A9.4040304(AT)ngunn.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
According to Mr Nyquist (I think that's who it was) you only need to sample at
twice the highest frequency contained in the sampled waveform but
remember that here we are talking about twice the frequency of the highest
harmonic contained in the waveform so 8KHz wouldn't be sufficient for
a 4KHz square wave but would be sufficient to reconstruct a 4KHz sine
wave..... or is my theory screwed up as well?
Gordon JC Pearce MM3YEQ wrote:
> Hmm. That's not quite true.
------------------------------
Message: 15
Date: Fri, 17 Oct 2008 09:27:13 -0400
From: Ben Jackson <bbj(AT)innismir.net>
Subject: [amsat-bb] Re: ISS recording Oct 16th 1338UTC
To: AMSAT-BB(AT)amsat.org
Message-ID: <48F892B1.1020304(AT)innismir.net>
Content-Type: text/plain; charset=ISO-8859-1
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Ben Jackson wrote:
> I've posted the SSTV pictures that I grabbed on various passes today and
> the recording of the voice pass (Garriott starts talking about 5
> minutes in) at http://www.innismir.net/article/49
For those of you who tried to download the recording last night, a typo
prevented you from doing so. I've fixed it and it should work fine now.
Thanks to Dave, AA4KN for pointing that out to me.
- --
Ben Jackson - N1WBV - New Bedford, MA
bbj <at> innismir.net - http://www.innismir.net/
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------------------------------
Message: 16
Date: Fri, 17 Oct 2008 09:38:19 -0400
From: santanaamt(AT)aol.com
Subject: [amsat-bb] ISS image yesterday
To: amsat-bb(AT)amsat.org, sarex(AT)amsat.org
Message-ID: <8CAFE74C07C7265-238-244D(AT)WEBMAIL-MC07.sysops.aol.com>
Content-Type: text/plain; charset="us-ascii"
Hi all:
Yesterday at 1204 UTC I did get an ISS image, and the interesting thing was
that it had on Hurricane Omar, for which we were lucky only a few rains fell
here. It was on Robot 36 and used MMSSTV and FT-857 w/ vertical AR-2. It's
like a P4 with some noise. Today did not received or heard anything, but let's
see.
Cheers,
Angel Santana - WP3GW
Trujillo Alto, PR? FK78aj
------------------------------
Message: 17
Date: Fri, 17 Oct 2008 06:40:34 -0700 (PDT)
From: MM <ka1rrw(AT)yahoo.com>
Subject: [amsat-bb] Re: New Batteries on the ISS, Its solar
To: "AMSAT.org" <amsat-bb(AT)amsat.org>, "Simon \(HB9DRV\)"
<simon(AT)hb9drv.ch>
Message-ID: <494811.46146.qm(AT)web56407.mail.re3.yahoo.com>
Content-Type: text/plain; charset=us-ascii
Actually it's on Solar Panels.
The ARISS VCH1 project will only run on Batteries.
The MarexMG SpaceCam1 project runs on a Laptop and uses grid power from the
Solar panels.
When you see big letters NA1SS, it is running on the VCH1.
When you see the Call sign and time Stamp at the bottom of the image, it is
running MarexMG SpaceCam1.
Request:
It looks like they may have figured out how to use the USB camera AND
SpaceCam1.
Please keep posting the images and sending copies to Marex at
sstv(AT)issspacecam.org.
Enjoy
WF1F, MarexMG.org
--- On Fri, 10/17/08, Simon (HB9DRV) <simon(AT)hb9drv.ch> wrote:
> From: Simon (HB9DRV) <simon(AT)hb9drv.ch>
> Subject: [amsat-bb] New Batteries on the ISS
> To: "AMSAT.org" <amsat-bb(AT)amsat.org>
> Date: Friday, October 17, 2008, 5:38 AM
> Pics being sent:
>
> http://www.ham-radio-deluxe.com/SSTV/tabid/85/Default.aspx
>
> Simon Brown, HB9DRV
> www.ham-radio-deluxe.com
> _______________________________________________
> Sent via AMSAT-BB(AT)amsat.org. 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: 18
Date: Fri, 17 Oct 2008 09:43:47 -0400
From: Curt Nixon <cptcurt(AT)flash.net>
Subject: [amsat-bb] Re: SSTV Algorithms?
To: nigel(AT)ngunn.net
Cc: amsat-bb(AT)amsat.org
Message-ID: <48F89693.7030907(AT)flash.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Nope...you got it just right!
As Simon pointed out, its all about knowing what information you want to
get from the "re-constructed" wave. If you want all the detail, you
have to sample at least 2f of the highest harmonic content. Square
waves with fast rising leading edges are a real mutha!! Its why we sold
alot of multi-gig one-shot samplers!
For repetitive waveforms, averaging with a sample rate much slower and
randomly distributed across the signal results in good reconstruction
but is not "realtime" or one-shot capable.
Curt
Nigel Gunn G8IFF/W8IFF wrote:
> According to Mr Nyquist (I think that's who it was) you only need to sample
at twice the highest frequency contained in the sampled waveform but
> remember that here we are talking about twice the frequency of the highest
harmonic contained in the waveform so 8KHz wouldn't be sufficient for
> a 4KHz square wave but would be sufficient to reconstruct a 4KHz sine
wave..... or is my theory screwed up as well?
>
>
> Gordon JC Pearce MM3YEQ wrote:
>
>
>> Hmm. That's not quite true.
>>
> _______________________________________________
> Sent via AMSAT-BB(AT)amsat.org. 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: 19
Date: Fri, 17 Oct 2008 10:15:54 -0400
From: "Mr Jeffrey L Ross" <radiooperator(AT)comcast.net>
Subject: [amsat-bb] ISS
To: "amsat" <amsat-bb(AT)amsat.org>
Message-ID: <8222AD36B19C4B2880EA19ED2C08CA10(AT)hamshackcomputer>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi folks, nothin heard from the ISS this last USA pass right thru the middle
of us, went ahead and xmited a cqsstv, in case they are listening. kc8gkf
1015am local EST.
------------------------------
Message: 20
Date: Fri, 17 Oct 2008 16:28:29 +0200
From: "Simon \(HB9DRV\)" <simon(AT)hb9drv.ch>
Subject: [amsat-bb] Re: ISS
To: "amsat" <amsat-bb(AT)amsat.org>
Message-ID: <87D6CDB484D340B3B29A41AAC3E263BE(AT)doubletrouble>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Nice pic over CH just now
http://www.ham-radio-deluxe.com/SSTV/tabid/85/Default.aspx
Simon Brown, HB9DRV
www.ham-radio-deluxe.com
----- Original Message -----
From: "Mr Jeffrey L Ross" <radiooperator(AT)comcast.net>
> Hi folks, nothin heard from the ISS this last USA pass right thru the
> middle
> of us, went ahead and xmited a cqsstv, in case they are listening. kc8gkf
> 1015am local EST.
>
------------------------------
_______________________________________________
Sent via amsat-bb(AT)amsat.org. 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 3, Issue 530
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