Thank you David for the format and thank you Bob for the cool information about how things actually work up there. I host a local 2 meter AMSAT info net here in the Dallas area on Tuesdays and Wednesdays of most weeks, and I wanted to bring up the PSAT-2 SSTV as a challenge to all the local folks who find it so easy to grab the ISS frames but are gonna have to work a little harder to get the stuff from this satellite. Bringing up challenges is a good thing. Unfortunately right now most of the North America passes are in the early morning hours but that will change back to full daylight passes in a few weeks.
So then a clarification just so I understand. When in sunlight with full battery the FM downlink carrier is Always-On, or only on when it hears a PSK signal? Does it do SSTV only if the power budget is good an carrier is always on doing an image every four minutes?
I will also go back and read Bob’s documentation on his website and that should help clarify and point people as well.
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On Jul 20, 2021, at 11:16, David Spoelstra davids@mediamachine.com wrote:
Bob - I believe Tom is asking what format the SSTV is sent in. Like the ISS images are PD120. I believe NO-104 images are sent in Robot 36 mode. -David, N9KT
On Tue, Jul 20, 2021 at 10:05 AM Tom Schuessler tjschuessler@verizon.net wrote: Barb, please remind us what SSTV mode is used on NO104?
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On Jul 19, 2021, at 18:28, Robert Bruninga bruninga@usna.edu wrote:
The only downside is that its orbit is at a 28 degree latitude and so is low on the southern horizon for northern states. Though the elevation goes up and down over a two week period by several degrees.
Let me know that it is working. Oh, also, the pass has to be in the sun for power and for live images. bob
On Mon, Jul 19, 2021 at 4:03 PM David Spoelstra davids@mediamachine.com wrote:
@WB4APR I didn't know that! When I read about the satellite initially I thought that you only got an SSTV image if someone was transmitting one. I didn't realize that it constantly transmitted what was in it's memory (at least I'm guessing that). I'm going to try that ASAP and let my club know too. Thanks! -David, N9KT
On Mon, Jul 19, 2021 at 1:43 PM Robert Bruninga bruninga@usna.edu wrote:
We have both. To receive SSTV, the APRS PSAT2 satellite supports it full time with an SSTV image once every 4 minutes full time 24/7/365.on 435.350 MHz.
In addition, users can also uplink their own images to the SSTV transponder on 29.481 MHz. See how on http://aprs.org/psat2.html
The transponder is also available for PSK31 users. - Bob, WB4APR
On Mon, Jul 19, 2021 at 1:13 PM GMM via AMSAT-BB amsat-bb@amsat.org wrote:
Best Project first: If you have multiple projects and limited resources, you need to choose the project that will be the most successful or Get the best bang for the buck. What are you goals for an Amateur-Radio project for ISS?
#1, Generate interest in Amateur radio capabilities. #2, Encourage Non-Amateur-radio people to possibly get-into the Amateur-Radio or SWL Hobby. #3, Get more people excited about the ISS and is open programs that can allow the average person to participate. #4, Provide the ISS crew with some entertaining and excitement about their projects. #5, Language universal projects work best.
The APRS project has a low following and does not generate much excitement or newspaper coverage. SSTV does great and all 5 of the listed categories. Why is SSTV better the APRS? SSTV is a project that will cross over between two hobbies, Short-wave-listening and Amateur radio. Most Short-wave-listening and Amateur operators are capable of receiving and decoding SSTV signals. With 10's of millions of SWL+AR stations receiving these signals month after month, you will see a huge interest in the abilities of Amateur Radio on ISS.
You must have heard the saying "A picture is worth a thousand words". When MarexMG was running the SSTV Program in Space Station Mir, out SSTV images were showing up in magazines and newspapers around the world.
When was the last time you saw a New paper or magazine story [Non-ham] talking about APRS from ISS? Never!
The MarexMG SSTV project was a huge hit. Schools around the world were setting up receiving stations to receive the images. I remember seeing a new story showing how the Great-Lakes ices was changing week after week, based on images from Mir SSTV.
If we want to build up a large amount of support for existing and future Amateur radio projects on ISS, then we need to put our best project front and center.
I am not talking about turning on SSTV for 1 or two weekend per year. I am talking about turning it on for a FULL 6 consecutive months in a row 24 hours a day, 7-days a week.
Image cycle duration: Let's keep is Simple and Safe. Recommended format: To provide the greatest access and reduce Heat stress on the radio, I recommend using SSTV format Robot-36.
The reason for the low-quality Robot-36, is because the transmitting time is only about 36 seconds for each image. I know this is the lowest quality image format, but since it’s the shortest, we can keep the radio cooler.
All transmitters run MUCH hotter in Zero Gravity! And if the ISS Air pressure is turned down from 14 psi to 10 psi [Usually during space walks], the radio will also run hotter at 10 psi, than at 14 psi.
Maximum number of ISS-transmitted images per hour. 1 image every 5 minutes or 20 per hour. And depending on heatsink temperature and cooling fan status, we may need to reduce the number of pictures per hour to keep the radio cool.
My goal is to expand the presence of Amateur Radio on ISS and other satellites and the best tools we have on ISS today is Slow Scan TV. Let's generate some worldwide excitement and make this hobby grow.
Turn off APRS!
Turn ON SSTV for a FULL 6 consecutive months in a row 24 hours a day, 7-days a week.
And then start watch the publicly generated by Marex SPACE-CAM1
by Miles, WF1F
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Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/
View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org