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CX2SA > SATDIG 25.11.08 05:05l 687 Lines 26032 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: Soundcard 9600 GMSK application? (Jens Kirsten)
2. Re: Soundcard 9600 GMSK application? (Ryan Butler)
3. Help for Humber College Students with ISS Contact (Ken Owen)
4. Re: thought for a neat product, anyone seen one?
(Mark Vandewettering)
5. thought for a neat product, anyone seen one? (Eric Fort)
6. Re: thought for a neat product, anyone seen one? (Eric Fort)
7. AO7 MODE A ORBIT 55724 - Lots of activity! (Mark Lunday, WD4ELG)
8. BBsat Call for ideas (JoAnne Maenpaa)
9. ICOM -820 repair :-( (Alvaro de Leon Romo)
10. Re: BBsat Call for ideas (Andrew Glasbrenner)
11. Re: BBsat Call for ideas (Tony Langdon)
12. Re: Help for Humber College Students with ISS Contact
(Kelly Martin)
13. another idea for a sat (Eric Fort)
----------------------------------------------------------------------
Message: 1
Date: Mon, 24 Nov 2008 21:04:49 +0100
From: Jens Kirsten <jens_kirsten@xxxxx.xx>
Subject: [amsat-bb] Re: Soundcard 9600 GMSK application?
To: amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID: <492B08E1.7070800@xxxxx.xx>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Maybe this is what you are looking for...
Multiplatform Soundcard Packet Radio Modem
by Thomas Sailer, HB9JNX/AE4WA
http://www.baycom.org/~tom/ham/soundmodem/
73! de DL2FJK
------------------------------
Message: 2
Date: Mon, 24 Nov 2008 15:53:19 -0600
From: Ryan Butler <rbutler@xxxx.xxx>
Subject: [amsat-bb] Re: Soundcard 9600 GMSK application?
To: Andrew Glasbrenner <glasbrenner@xxxxxxxxxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Message-ID: <492B224F.3010603@xxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Andrew Glasbrenner wrote:
> Is anyone aware of a soundcard application to emulate a GMSK 9k6 modem ?
>
> 73, Drew KO4MA
> _______________________________________________
> 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
>
gnuradio has a software GMSK implementation where you should be able to
define bit rate and BT.
Ryan Butler, NF0T
------------------------------
Message: 3
Date: Mon, 24 Nov 2008 15:20:18 -0800
From: "Ken Owen" <n6kth@xxxxx.xxx>
Subject: [amsat-bb] Help for Humber College Students with ISS Contact
To: <amsat-bb@xxxxx.xxx>
Cc: paul_je@xxxxxxx.xxx
Message-ID: <EC0D3712334942B8A25E082ED33020C1@xxxx>
Content-Type: text/plain; charset="us-ascii"
Hi folks:
A student from Humber College (Toronto) has asked me several questions
regarding contacting the ISS. One has to do with receiving a beacon, and
the other has to do with antenna polarization. I've urged him to join AMSAT
and get on the listserv, but in the mean time, I wonder if anyone can help
him out with his questions.
Please reply directly to him (paul_je@xxxxxxx.xxxx if you can help.
Thanks!
Ken, N6KTH
From: Paul Je [mailto:paul_je@xxxxxxx.xxxx
Sent: Monday, November 24, 2008 1:17 PM
To: Ken Owen
Subject: RE: ISS contact
Say Ken, we've set up our primary station just fine, but I was wondering if
I could ask for your advice. Well, you see, we've tested the transceiver
that we have (the ICOM IC-V8000), and we can transmit and receive just fine
with it on our circular-polarized HyGain 2m antenna. Also, we did a VSWR
test and our loss is minimal with the 75W transceiver that the ICOM
produces. Ok, so here's the problem. Even with all the proper testing
done, we still can't seem to pick up or hear the 166MHz beacon that the ISS
produces.
My classmates and I are a bit worried/stressed out. I mean, just on last
Friday, we did a test and someone drove at least 5km away from out college
and heard us fine with the handheld radio he had. We had a signal strength
of 3+ out of 5. He could've drove out even further, but we felt that we did
enough testing to know that any attenuation losses were very minimal.
Well, do you know what the problem could be? Have you heard the beacon?
What does it sound like? Maybe we should delay or advance the rotor by a
few seconds? We're using NOVA software, and it allows us to send our
transmission a few seconds ahead or behind.
Ok, so we have a circular polarized HyGain antenna hooked up to our Yaesu
G5500. Uhm, this might sound dumb but do you know whether we should be
right hand circular polarized or left hand circular polarized? Is the ISS
right hand or left hand on 144.490MHz?
I'm trying to research this, but I'm having the hardest time to find this
information out. Oh, also, since our antenna is circular-polarized, does
the way we set our antenna have an effect on our transmission? I know this
sounds confusing, but let me explain:
If you looked at our antenna from the front so that you could see all the
dipoles/elements both vertically and horizontally to your view, well, should
they be perfectly aligned with one set horizontal and one vertical? Both
the vertical and the horizontal are perfectly 90degrees to each other,
however, instead of being a perfect cross to your view, the elements are
more like an "X" to your point of view (even though both are perfectly
90degrees to each other).
Well, hope to hear back from you.
Paul
------------------------------
Message: 4
Date: Mon, 24 Nov 2008 15:25:26 -0800
From: Mark Vandewettering <kf6kyi@xxxxx.xxx>
Subject: [amsat-bb] Re: thought for a neat product, anyone seen one?
To: eric.fort@xxxxx.xxx
Cc: AMSAT-BB bb <amsat-bb@xxxxx.xxx>
Message-ID: <88FFDDD6-8377-4CF8-81D4-2F26524CE0C5@xxxxx.xxx>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
I have the same rig, and much the same idea. I haven't gotten very
far along with this idea, but
here's where my thinking takes me. I've implemented Miller's "Plan
13" algorithm in Python, and
currently use it to plan all my satellite operations. On any
reasonable laptop, it runs many times
faster than real time, even while running in Python, so it seems like
overkill to carry a laptop
with you to do satellite operations. The laptop is expensive, bulky,
and hard to use in the field
while aiming an antenna by hand, has limited battery life, etc.
Clearly, a more limited computer
can do all that we really need. If you look at G6LVB's latest/
greatest antenna tracker:
http://www.g6lvb.com/Articles/LVBTracker2/index.htm
you can see that he does all that you want using just a PIC
microcontroller. My own personal
bias is against the PIC though: I prefer the Atmel AVR chips, and in
particular have been having
a great deal of fun with the Arduino microcontroller board. I suspect
that if I back ported my
Python code into C and put it on the Arduino, I could still get an
update rate approaching 1Hz,
which should be good enough for the purposes we desire. The Arduino
also has a nice little
piggyback ethernet board. Here's what I imagine the usage is. While
at home, you plug this
thing into your home network. It then contacts celestrak or whatever,
and automatically downloads
the TLE for current amateur satellites. You can then disconnect the
rig from your home network, and
it's ready to carry into the field. A couple of buttons on the box
allow you to cycle through
satellites, giving the elevation and azimuth of the satellite. The
Arduino also has a serial port
which we can hook to the FT-817, and use it to control the 817 with
doppler. It would be a pretty
simple project, requiring three modules (arduino, ethernet shield and
display) and a few extra
buttons etc... Total cost probably around $100 or so. Could
probably run off batteries for days.
I probably won't get back to working on this until after the first of
the year, but if anyone
is interested, some enthusiasm might further motivate me to get the
software working.
Mark
------------------------------
Message: 5
Date: Mon, 24 Nov 2008 15:52:02 -0800
From: "Eric Fort" <eric.fort@xxxxx.xxx>
Subject: [amsat-bb] thought for a neat product, anyone seen one?
To: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID:
<2ad2af430811241552n50bd2dd0w898db860c029ac36@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Interesting you mention gumstix, it was one of my first ideas for hardware
to base something like this on. the nice thing about basing something like
a tracker on gumstix is all the software is already written. It should run
predict directly or most any other curses based linux app, or for that
matter your favorite script interpreter, etc. I also found the lvb tracker
2 shortly after I asked but that seems not to have gone anywhere. It's
probably the closest thing to what I'd be looking for but it seems a bit
large to lug around as would be a laptop. mostly what I would be looking
for is a small unit that I could directly use for frequency control but I'm
realizing now that once there you've built that you are only a few
transistors away from a full tracker. maybe amsat (or tapr) could do a
gumstix refrence platform.
Eric
AF6EP
On Mon, Nov 24, 2008 at 5:06 AM, Ben Jackson <bbj@xxxxxxxx.xxx> wrote:
> Eric Fort wrote:
> > I just thought of kind of a neat product for those of us that work sats.
> > Has anyone seen anything similar? I have an ft-817 which has a cat
> > interface and will operate both ssb and fm. Has anyone seen a little box
> > that would adjust the radio frequency for both uplink and downlink while
> > displaying azmuth and elevation data? It seems that it would be handy to
> > have the frequency control take care of itself while providing data as to
> > where I should point the arrow. What do those reading this idea think of
> > it? It would seem to me to be quite useful especially for ssb.
>
> I think it was Mark VandeWettering, KF6KYI, who had a similar idea a few
> months ago. Last I heard I think he was toying around with the idea of
> using a Gumstix
(http://www.gumstix.com/)device<http://www.gumstix.com/%29device>to be the
"black box." -
> There was a reason he didn't pursue it, but I forget why.
>
> This is a easily extensible system that can be hacked up to control
> doppler and handle basic radio functions. One could probably have a
> simple system banged out in an afternoon. As it gets more complicated
> (external display to control satellite selection, etc) it gets a touch
> harder to make, but still within the realm of possibility. The good part
> about Gumstix is that you don't need to get the hardware first to start
> working on the software, as it's all based on Linux.
>
> I think this idea has a lot of promise, and if I had a transceiver that
> could computer control, I'd probably start designing it. :)
>
> --
> Ben Jackson - N1WBV - New Bedford, MA
> bbj <at> innismir.net - http://www.innismir.net/
>
------------------------------
Message: 6
Date: Mon, 24 Nov 2008 16:01:28 -0800
From: "Eric Fort" <eric.fort@xxxxx.xxx>
Subject: [amsat-bb] Re: thought for a neat product, anyone seen one?
To: "Mark Vandewettering" <kf6kyi@xxxxx.xxx>
Cc: AMSAT-BB bb <amsat-bb@xxxxx.xxx>
Message-ID:
<2ad2af430811241601p5e3280beo51c377d8ca42472f@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
well put and pretty much what I was looking at. I also prefer the avr over
the pic so I'd looked at the AVRUSBKEY and the gumstix line. both have
definate possibilities. I think the gumstix would be easier to build upon
as you are basicly carrying a tiny linux computer and everything has already
been implimented in linux but if you are most of the way there with the avr
that seems like something I'd really be interested in. please let us know
how this progresses. maybe a bunch of us could adopt a group project.
Eric Fort
AF6EP
On Mon, Nov 24, 2008 at 3:25 PM, Mark Vandewettering <kf6kyi@xxxxx.xxx>wrote:
>
> I have the same rig, and much the same idea. I haven't gotten very far
> along with this idea, but
> here's where my thinking takes me. I've implemented Miller's "Plan 13"
> algorithm in Python, and
> currently use it to plan all my satellite operations. On any reasonable
> laptop, it runs many times
> faster than real time, even while running in Python, so it seems like
> overkill to carry a laptop
> with you to do satellite operations. The laptop is expensive, bulky, and
> hard to use in the field
> while aiming an antenna by hand, has limited battery life, etc. Clearly,
> a more limited computer
> can do all that we really need. If you look at G6LVB's latest/greatest
> antenna tracker:
>
> http://www.g6lvb.com/Articles/LVBTracker2/index.htm
>
> you can see that he does all that you want using just a PIC
> microcontroller. My own personal
> bias is against the PIC though: I prefer the Atmel AVR chips, and in
> particular have been having
> a great deal of fun with the Arduino microcontroller board. I suspect that
> if I back ported my
> Python code into C and put it on the Arduino, I could still get an update
> rate approaching 1Hz,
> which should be good enough for the purposes we desire. The Arduino also
> has a nice little
> piggyback ethernet board. Here's what I imagine the usage is. While at
> home, you plug this
> thing into your home network. It then contacts celestrak or whatever, and
> automatically downloads
> the TLE for current amateur satellites. You can then disconnect the rig
> from your home network, and
> it's ready to carry into the field. A couple of buttons on the box allow
> you to cycle through
> satellites, giving the elevation and azimuth of the satellite. The Arduino
> also has a serial port
> which we can hook to the FT-817, and use it to control the 817 with
> doppler. It would be a pretty
> simple project, requiring three modules (arduino, ethernet shield and
> display) and a few extra
> buttons etc... Total cost probably around $100 or so. Could probably run
> off batteries for days.
>
> I probably won't get back to working on this until after the first of the
> year, but if anyone
> is interested, some enthusiasm might further motivate me to get the
> software working.
>
> Mark
>
>
------------------------------
Message: 7
Date: Mon, 24 Nov 2008 19:53:28 -0500
From: "Mark Lunday, WD4ELG" <mlunday@xx.xx.xxx>
Subject: [amsat-bb] AO7 MODE A ORBIT 55724 - Lots of activity!
To: <amsat-bb@xxxxx.xxx>
Message-ID: <000f01c94e98$3bf9ec40$b3edc4c0$@xx.xxx>
Content-Type: text/plain; charset="us-ascii"
Worked Ed, W0ODD, in Kansas on CW. Heard a bunch of SSB stations. Great
signals on mode A. Nice to hear activity! Exciting!!
Mark Lunday
WD4ELG
wd4elg@xxxx.xxx
http://wd4elg.net
------------------------------
Message: 8
Date: Mon, 24 Nov 2008 19:40:51 -0600
From: "JoAnne Maenpaa" <k9jkm@xxxxxxx.xxx>
Subject: [amsat-bb] BBsat Call for ideas
To: <AMSAT-BB@xxxxx.xxx>
Message-ID: <001201c94e9e$da525d40$8ef717c0$@xxx>
Content-Type: text/plain; charset="us-ascii"
Ok folks,
Its time for some fun ... how about we design and fly our own transponder
via the amsat-bb?
I propose BBSat (sounds better than AdHocSat). This is a call for ideas of
a single board transponder in cubesat form factor ... what can we put on a
10cm ^2 circuit board? FM, SDR, packet?
Initially there are only two rules ...
1) No griping
2) This is going to be an open source project
Let us know what you think right here on the -bb ...
--
73 de JoAnne K9JKM
k9jkm@xxxxx.xxx
------------------------------
Message: 9
Date: Mon, 24 Nov 2008 20:01:02 -0600
From: Alvaro de Leon Romo <xe2at@xxxxxxx.xxx>
Subject: [amsat-bb] ICOM -820 repair :-(
To: <amsat-bb@xxxxx.xxx>
Cc: moon-net@xxxxxxxxx.xxxxx.xxx
Message-ID: <BAY124-W54A2378A8E4963D457F68F50B0@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
Hi , after several years my IC820 have some problem , the radio not respond to
instructions about to input the high and low power level and now not transmit
:-(
Some one here know what is the better way to fix this radio ? ICOM AMERICA is
the best choice ??
I will fly to Tx so I need the info where to send the radio to reapair ...
Is the cost too high ?
Many thanks for your valious time
Sincerely Al
XE2AT
_________________________________________________________________
Realiza b?squedas en Internet y ll?vate hasta ?Un Auto!
http://www.ganabuscando.com/Default.aspx
------------------------------
Message: 10
Date: Mon, 24 Nov 2008 21:01:06 -0500
From: "Andrew Glasbrenner" <glasbrenner@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: BBsat Call for ideas
To: "JoAnne Maenpaa" <k9jkm@xxxxxxx.xxx>, <AMSAT-BB@xxxxx.xxx>
Message-ID: <A2E74131921E41F48C4696CA055BD0FA@xxxxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I'll play!
On the drive home from the symposium in Atlanta, I was thinking about a
cubesat with a "hybrid" voice repeater. My idea would use a 435 FM uplink
because it's easy to generate power enough on the ground, and the Doppler
shift moves QRM out of the uplink fast, it's FM and not picky about tuning,
and there aren't any illegal telephones that work on the uplink AFAIK. We'd
use a 2m SSB downlink, for a few reasons. 2m path loss is less, so given
similar antennas we'll get a better downlink. SSB is more efficient than FM,
and we also save power by not transmitting unless there is audio on the
uplink, a squelch of sorts.
No computer on my satellite either! We'd have some sort of hardware timer
that has to be reset every few days to keep the repeater running, so we
could meet FCC rules on control. Maybe PL or DTMF?
Wouldn't it be neat to have one of these sitting on the shelf in case a
empty spot on a PPOD became available?
73, Drew KO4MA
----- Original Message -----
From: "JoAnne Maenpaa" <k9jkm@xxxxxxx.xxx>
To: <AMSAT-BB@xxxxx.xxx>
Sent: Monday, November 24, 2008 8:40 PM
Subject: [amsat-bb] BBsat Call for ideas
> Ok folks,
>
> Its time for some fun ... how about we design and fly our own transponder
> via the amsat-bb?
>
> I propose BBSat (sounds better than AdHocSat). This is a call for ideas
> of
> a single board transponder in cubesat form factor ... what can we put on a
> 10cm ^2 circuit board? FM, SDR, packet?
>
> Initially there are only two rules ...
> 1) No griping
> 2) This is going to be an open source project
>
> Let us know what you think right here on the -bb ...
>
> --
> 73 de JoAnne K9JKM
> k9jkm@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
------------------------------
Message: 11
Date: Tue, 25 Nov 2008 13:38:03 +1100
From: Tony Langdon <vk3jed@xxxxx.xxx>
Subject: [amsat-bb] Re: BBsat Call for ideas
To: "Andrew Glasbrenner" <glasbrenner@xxxxxxxxxx.xxx>, "JoAnne
Maenpaa" <k9jkm@xxxxxxx.xxx>, <AMSAT-BB@xxxxx.xxx>
Message-ID: <492b6513.29578c0a.5674.ffff89cb@xx.xxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 01:01 PM 11/25/2008, Andrew Glasbrenner wrote:
>On the drive home from the symposium in Atlanta, I was thinking about a
>cubesat with a "hybrid" voice repeater. My idea would use a 435 FM uplink
>because it's easy to generate power enough on the ground, and the Doppler
>shift moves QRM out of the uplink fast, it's FM and not picky about tuning,
>and there aren't any illegal telephones that work on the uplink AFAIK. We'd
>use a 2m SSB downlink, for a few reasons. 2m path loss is less, so given
>similar antennas we'll get a better downlink. SSB is more efficient than FM,
>and we also save power by not transmitting unless there is audio on the
>uplink, a squelch of sorts.
Interesting idea, except I do have one quibble - normally when there
is no signal on FM, there would be the background noise at high
level. You would need to have squelch on the bird to cut the Tx power to
zero.
>No computer on my satellite either! We'd have some sort of hardware timer
>that has to be reset every few days to keep the repeater running, so we
>could meet FCC rules on control. Maybe PL or DTMF?
>
>Wouldn't it be neat to have one of these sitting on the shelf in case a
>empty spot on a PPOD became available?
Could be neat to have a simple bird to throw up at the drop of a
hat. Also there are more 2m SSB radios than 70cm ones in service
down this way, so this is a goer in my book. :)
73 de VK3JED
http://vkradio.com
------------------------------
Message: 12
Date: Mon, 24 Nov 2008 18:03:53 -0600
From: "Kelly Martin" <kelly.lynn.martin@xxxxx.xxx>
Subject: [amsat-bb] Re: Help for Humber College Students with ISS
Contact
To: "Ken Owen" <n6kth@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx paul_je@xxxxxxx.xxx
Message-ID:
<bd4c411e0811241603n3f230c88l4df0d97ead6bbfa5@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
These are the people whose professor famously told the Toronto Star
said that only professional radio engineers had the knowledge and
competency to contact the ISS. I wrote the professor a letter, but he
never replied.
I suspect their main problem is that they're using an excessively
high-gain antenna, which means it's extremely directional and thus the
targeting has to be very precise.
Also, it might help if they listened on the DOWNLINK frequency instead
of the UPLINK frequency.
Kelly
On Mon, Nov 24, 2008 at 5:20 PM, Ken Owen <n6kth@xxxxx.xxx> wrote:
> Hi folks:
>
> A student from Humber College (Toronto) has asked me several questions
> regarding contacting the ISS. One has to do with receiving a beacon, and
> the other has to do with antenna polarization. I've urged him to join AMSAT
> and get on the listserv, but in the mean time, I wonder if anyone can help
> him out with his questions.
>
> Please reply directly to him (paul_je@xxxxxxx.xxxx if you can help.
>
> Thanks!
>
> Ken, N6KTH
>
>
>
> From: Paul Je [mailto:paul_je@xxxxxxx.xxxx
> Sent: Monday, November 24, 2008 1:17 PM
> To: Ken Owen
> Subject: RE: ISS contact
>
> Say Ken, we've set up our primary station just fine, but I was wondering if
> I could ask for your advice. Well, you see, we've tested the transceiver
> that we have (the ICOM IC-V8000), and we can transmit and receive just fine
> with it on our circular-polarized HyGain 2m antenna. Also, we did a VSWR
> test and our loss is minimal with the 75W transceiver that the ICOM
> produces. Ok, so here's the problem. Even with all the proper testing
> done, we still can't seem to pick up or hear the 166MHz beacon that the ISS
> produces.
>
> My classmates and I are a bit worried/stressed out. I mean, just on last
> Friday, we did a test and someone drove at least 5km away from out college
> and heard us fine with the handheld radio he had. We had a signal strength
> of 3+ out of 5. He could've drove out even further, but we felt that we did
> enough testing to know that any attenuation losses were very minimal.
>
> Well, do you know what the problem could be? Have you heard the beacon?
> What does it sound like? Maybe we should delay or advance the rotor by a
> few seconds? We're using NOVA software, and it allows us to send our
> transmission a few seconds ahead or behind.
>
> Ok, so we have a circular polarized HyGain antenna hooked up to our Yaesu
> G5500. Uhm, this might sound dumb but do you know whether we should be
> right hand circular polarized or left hand circular polarized? Is the ISS
> right hand or left hand on 144.490MHz?
>
> I'm trying to research this, but I'm having the hardest time to find this
> information out. Oh, also, since our antenna is circular-polarized, does
> the way we set our antenna have an effect on our transmission? I know this
> sounds confusing, but let me explain:
>
> If you looked at our antenna from the front so that you could see all the
> dipoles/elements both vertically and horizontally to your view, well, should
> they be perfectly aligned with one set horizontal and one vertical? Both
> the vertical and the horizontal are perfectly 90degrees to each other,
> however, instead of being a perfect cross to your view, the elements are
> more like an "X" to your point of view (even though both are perfectly
> 90degrees to each other).
>
> Well, hope to hear back from you.
>
> Paul
>
> _______________________________________________
> 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: Mon, 24 Nov 2008 18:57:17 -0800
From: "Eric Fort" <eric.fort@xxxxx.xxx>
Subject: [amsat-bb] another idea for a sat
To: "AMSAT-BB bb" <amsat-bb@xxxxx.xxx>
Message-ID:
<2ad2af430811241857i18cbafa9o948b108dc730e007@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
What would you think of a sat that required no user frequency control for
uplink or downlink and carried somewhere between 10 and 30 simultanious
conversations? Here's how it can be done and it's a mode that I think
deserves more investigation - ACSB, possibly with a twist. for those not
familiar with ACSB, it's essentially SSB with a subaudable tone inserted.
on recieve that subaudable tone of known frequency can be used for tuning
and doppler adjustment. Taken a step further one could use the on sat
beacon as the reference "tone" and simply maintain a frequency exactly a
certain distance from that. come to think of it we could experiment with
this now on the ssb birds we have now. anyone interested in trying this?
has it been tried? what do you think?
Eric
AF6EP
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End of AMSAT-BB Digest, Vol 3, Issue 607
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