Technical papers are solicited for presentation at the 26th Annual ARRL
and TAPR Digital Communications Conference to be held September 28-30,
2007 in Hartford, Connecticut. These papers will also be published in
the Conference Proceedings (you do NOT need to attend the conference to
have your paper included in the Proceedings). The submission deadline is
July 31, 2007. Please send papers to:
225 Main St
Newington, CT 06111
or you can make your submission via e-mail to: maty(a)arrl.org
Papers will be published exactly as submitted and authors will retain
73 . . . Steve, WB8IMY
Dear AMSAT friends
My pacsat station is for sale:
Kenwood TS-790A 144/432/1200 MHz transciever
with the following extras:
* UT-10 1200 MHz module
* Symek IFD-B board (for speed up to 76000 bd)
* extended rx (on 3 bands)
* 9600 baud tx/rx
* 100ms mute disabled
* IFD-B board (38400 baud rx)
* Hand microphone
* DC cable
* Instruction Manual (in english) include schematics
* External Control Instruction Manual (in english)
* Modifications documentation (in english)
All mods were performed by me and no holes were done.
This equipment was bought new (1997), and until now
there was not a single problem! It was kept on a non
Cosmetic is a 8/10 (one minor dent, sort of paint bubble
and 4 rotator control box feet "stain", all on top cover)
Unfortunatly I don't have the original box anymore. Sorry
TNC Symek TNC31S
* Tx 9600/Rx 38400 baud card
* 128kb RAM
* 512kb Flash-EPROM
* English mailbox
* Kiss autostart
* RS232 cable plus adapter (DB9)
* DC cable
* Diskette with software
* Original Manuals (english and german)
This TNC was bought new (2000), and was used on UO-36
and Tiungsat-1 with great sucess. I did't use it since
a long time ago, but I belive it's 100% operational.
Cosmetic is 9/10.
I will only sale the 2 items together. Price: 1500 Euro
Buyer pays shipping.
Euro countries: Bank money transfer only!
Elsewhere: Western Union or PayPal.
Photos: please visit http://ct1eatsale.no.sapo.pt/
Thanks for your attention.
See you on P3E or Eagle.
73 F.Costa, CT1EAT
Amen on InstantTrack!! IT!!!
I was fortunate enuff to be one of the beta testers, many moons ago.
I use SatPC32 to control my rotors now, but I always parallel it with
IT on another computer to do some of the things that PC32 does not do...
I don't know how any serious satellite operator would be without
either one, for the pittance they cost in comparison to what they
need to do anything on any amateur bird!!
Or if one has ANY interest in either the sun or the moon....
73, Dave wb6llo(a)amsat.org
Disagree: I learn....
Pulling for P3E...
I've been considering petitioning the IOTA board to make a special award for IOTA contacts made via satellite. Right now their rules (http://www.rsgbiota.org/rules/rules.pdf, Para C.3.10) do not allow satellite contacts for any award.
Are there others here that would support such a petition?
I have a question regarding software doppler correction - in particular
when using linear satellites.
I am working on some control software that is a little more flexible than
what I've used. I really like SatPC32 on Windows and Predict/gsat on
Linux. I haven't yet fallen in love with any available software, but
that's really a different story.
I can imagine that doppler correction for an FM sat is rather easy in that
you simply tune the transmitter/receiver to the published frequencies
depending on the operating mode.
I'm a little less sure how that would work for a linear satellite. As
mentioned before, I do have a chart from AMSAT that lists channelized
frequencies for them. If I can tune the transmitter such that the
frequency at the satellite is one of the listed frequencies, how sure can
I be that the receive is as published?
Can I extend that to the point where I would be able to automatically
determine frequencies (at the satellite) of the downlink for a given
uplink and then compute doppler from there? It would then be fairly
convenient to tune within the satellite's passband and let the computer do
Thanks for any feedback.
Next Tuesday on the 9 and 10 AM EDT passes over the East Coast, we hope to do a class demonstration via GO-32.
We will be looking for other APRS stations and trying to message anyone we see. Mark your calendar if you get a chance. More will be posted later.
If anyone can run heir sat station as an IGate, that too would help us capture all packets.
Naval Academy Satellite Lab
As long as satellite tracking is the subject; gpredict just released
version 0.9.0. It looks nice, and seems to have cured the freezes
I was getting in the Polar View window. Well done Alex and crew!
Bob - AE6RV
> Back to my "new" [18"] dish... Being that it
> is an offset dish, is 1.2GHz possible with
> this dish?
> Anyone tried this?
Yes. I tried it for our satellite labs for students and althogh I get about 14 dB or so measured gain with it at 2.4 GHz, at 1.2 GHz, it was nothing more than a big piece of metal giving no more gain than a flat reflector... maybe between 3 to 6 dB.
See the photo of its use at 2.4 GHz on the top of this page:
With the antenna for one of those $75 wireless camera receivers at the focal point, and the companion little wireless camera as a signal source a mile away with only its 1.5" whip antenna, we receive the picture perfectly with a margin of at least 16 dB. This means the picture would still be good out to maybe 6 miles...
It sure is an easy way to get into Amateur TV. Even though it does not even require a license..
But if there are wireless LANS around, then the picture gets lots of QRM..
To say the hardware does not not get any simpler is perhaps true for the
number of components, but the complexity within those components is much greater
than anything flown before in AMSAT transponders. It's probably true to say
that Eagle will use 20,000 transistors to do the same job as 20 transistors
in Oscar 7. But it's also fair to say those 20,000 transistors will do a much
The SDX technology will get its first on orbit test with suitsat2. That
will tell us all something about reliability in LEO before launching Eagle and
In 2009 The SSETI ESEO mission to a higher radiation geostationary transfer
orbit will include a mode U/S transponder. It converts 435 down to 10.7MHz and
that signal can be routed to a software defined transponder or to a
conventional linear transponder before being upconverted to 2401MHz. Hopefully, the
SDX will perform flawlessly, but should there be a problem, then the
satellite can be commanded to bypass the SDX and use a traditional circuit.
Somewhere along the line an SDX will be designed that is reliable and give
much better performance than whats been flown in the past. It's a learning
curve, there may be problems along the way, but we have moved on since October
4th 1957 and we need to investigate new technologies and sort out what works
and what does not.
Happy 50th birthday Sputnik (I wonder how many valves were inside that?)
In a message dated 30/09/2007 16:06:16 GMT Standard Time, hartzell(a)gmail.com
Even as a proponent for SDR (and an SDR "user"), the lingering thought
in my mind regarding SDX in space is survivability.
There is no flight heritage (yet) for an SDX in space, and there is
quite a bit of complexity with regards to software and integrated
components (ADCs, DACs, FPGAs, CPUs, etc.).
But these problems plague analong XPNDRs as well....with the right
selection of components, de-rating of components, and rad-hardened
when feasible, chances for success increase.
On 9/30/07, David B. Toth <ve3gyq(a)amsat.org> wrote:
> Patrick: it is too bad that you were unable to join us here in
> Hartford, CT this weekend for the TAPR-ARRL DCC ...
> There were many presentations on SDR, some by AMSAT personnel ...
> The hardware does not GET any simpler than in SDX ... the HUGE
> advantage is that a component with a shifting value (such as might
> occur in a spacecraft with wide temperature swings) does not degrade
> the performance/optimization of a device, because if the hardware
> does age/shift, then that can be compensated for in software ...
Easysat ? ... right !!!l.
I've been trying (unsuccessfully) to figure out how to tell when the AO-27 transmitter is switched on over my QTH ... (Frei Island JP33WB) ... or not.
Of course, any tracking program tells me *WHEN* the satellite is over my QTH but tracking programs don't tell me whether the transmitter is switched on or not.
The AO-27 scheduler supposedly does this ... the only problem is
... I find it thoroughly confusing.
The passes (according to any tracking program with the latest keps) and the AO-27 scheduler don't seem to agree ... (me'thinks John is doing something wrong !!!) ... or ... from the scheduler I can see if the transmitters are on (or not) when the satellite is well out of my footprint ... but I'd like to know whether it's on when the satellite is workable from my QTH.
Is there anyone out there who can explain in words of one syllable (or less) how one figures this out ... and then explain it to a thick and illiterate old sod like me.
This mail is in NO WAY meant as any form of criticism of the AO-27 scheduler, it is ENTIRELY me being TOTALLY stupid! and not being able to see the wood for the trees ... and asking for HELP.
How about an example that a 5 year old could understand?
(Even I might have a chance then).
73 John. <la2qaa(a)amsat.org>