- pacsat-dev - mailman.amsat.org

GOTO problems
by Bill 27 Sep '24

27 Sep '24

Well, something is broken in goto meeting. I am cancelling tonights meeting and we can meet next Thursday. Use the pacsat-dev mailing list if you have something urgent. Bill

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Re: Pacsat dev mtg 9/26/2024
by Blumenthal, Alex 27 Sep '24

27 Sep '24

Hi all, Am I the only one having trouble joining the meeting or is it not working for others? -Alex ________________________________ From: Bill via pacsat-dev <pacsat-dev(a)amsat.org> Sent: Thursday, September 26, 2024 3:18 PM To: pacsat-dev(a)amsat.org <pacsat-dev(a)amsat.org>; k4mvm.22(a)gmail.com <k4mvm.22(a)gmail.com> Subject: [pacsat-dev] Pacsat dev mtg 9/26/2024 Pacsat dev mtg 9/26/2024 Thu, Sep 26, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/409444917 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (571) 317-3112 - One-touch: tel:+15713173112,,409444917# Access Code: 409-444-917 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 409 444 917 Or dial directly: 409444917(a)67.217.95.2 or 67.217.95.2##409444917 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install ----------------------------------------------------------- pacsat-dev mailing list -- pacsat-dev(a)amsat.org View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/pacsat-dev@amsat.org To unsubscribe send an email to pacsat-dev-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Pacsat dev mtg 9/26/2024
by Bill 27 Sep '24

27 Sep '24

Pacsat dev mtg 9/26/2024 Thu, Sep 26, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/409444917 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (571) 317-3112 - One-touch: tel:+15713173112,,409444917# Access Code: 409-444-917 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 409 444 917 Or dial directly: 409444917(a)67.217.95.2 or 67.217.95.2##409444917 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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Re: Amplifier Options & MEMS switches
by Jim McCullers 20 Sep '24

20 Sep '24

Thanks Cameron. I’ll take a look. During last night’s meeting a discussion on using Class C as an amplifier option was discussed. There was additional discussion concerning BPSK and non-linear amplifiers. After the meeting I reviewed BPSK. BPSK is a constant amplitude modulation and therefore can be amplified using non-linear amplification (Class C). The difference in BPSK and FSK is the incorporation of phase shift keying between the two modulation frequencies rather than frequency shift keying as in FSK. Actually it would be correct to refer to FSK as BFSK as both imply a shift between two frequencies. I believe the confusion about BPSK is that it is often demodulated using SSB, more correctly slope detection as many demodulator systems to not support BPSK. I’m not certain if there are Class C modules available and the availability of discrete RF transistors for 70cm and low power. Jim McCullers WA4CWI Good evening, I wanted to follow up on some of the PAs I've been looking at. They're ordered from most to least preferred. I'm not very experienced, so any advice will be well received! * GRF5504 <https://www.guerrilla-rf.com/products/DataSheet?sku=5504&file_name=GRF5504D…> : P1dB of 34.3 dBm @ 460 MHz, so approximately the correct power levels. Very inexpensive and optimized for 70 cm applications (unlike many of the other options). The high gain (44 dB) may warrant less strain on the AX5043 PA and perhaps better performance out of the class E. Its main drawback is poor efficiency, which is expected to be around 50% @ 33dBm (see page 9). * MMG3006NT1 <https://www.mouser.com/datasheet/2/302/MMG3006NT1-3138450.pdf> : I'm a little skeptical of this device as all the measurements are taken at >900 MHz. We'd be using the device at its very lowest end of operation. At the measured frequency, performance is pretty good: P1dB = 33 dBm, 17.5 dB of gain, 2 dB higher NF than the former option. I'd want to test this device before implementing it on the board, as we'd be taking a risk using it at its lower end. * TQP7M9106 <https://www.mouser.com/datasheet/2/412/QP7M9106-1500761.pdf> : They really flaunt the high linearity and bandwidth of this amplifier, but it does have acceptable characteristics at the desired frequencies. Noise figure is around the same as the first option, and current consumption is between the other options. I'm leaning towards the GRF5504 since it seems the most suited for the application, but maybe I'm wrong. There aren't a lot of good options in the 70 cm band. I can test it against a discrete amplifier on our PA test board. I know we're sharing the antenna module with FOX+. Does anyone know how we're switching the resource to the antenna? Perhaps that's a question for the ICD manager. I wanted to suggest using MEMS switches since they're more reliable and take up less board space. We use them at work for our serializer channel switches. I'm not sure how they'll hold up at 2W, but they've proved better than relays in almost every sense. Here <https://www.mdpi.com/1424-8220/24/10/3135> is a report on MEMS switches for antenna switching for space applications. I also wanted to mention that I wrote a report <https://docs.google.com/document/d/1N9ZAk-9m667yN1V_LVc1hHOa87ftJdjcrTFCgRI…> on possible AX5043 replacements (not for an AMSAT group). I know it's not at the top of the list of things to do, but it might be a starting point for someone. Thanks! Cameron ------------------------------------------------- Cameron Castillo KJ7ILB P: (503) 752-8877 --------------------------------------------------

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Amplifier Options & MEMS switches
by Cameron Castillo 20 Sep '24

20 Sep '24

Good evening, I wanted to follow up on some of the PAs I've been looking at. They're ordered from most to least preferred. I'm not very experienced, so any advice will be well received! - GRF5504 <https://www.guerrilla-rf.com/products/DataSheet?sku=5504&file_name=GRF5504D…>: P1dB of 34.3 dBm @ 460 MHz, so approximately the correct power levels. Very inexpensive and optimized for 70 cm applications (unlike many of the other options). The high gain (44 dB) may warrant less strain on the AX5043 PA and perhaps better performance out of the class E. Its main drawback is poor efficiency, which is expected to be around 50% @ 33dBm (see page 9). - MMG3006NT1 <https://www.mouser.com/datasheet/2/302/MMG3006NT1-3138450.pdf>: I'm a little skeptical of this device as all the measurements are taken at >900 MHz. We'd be using the device at its very lowest end of operation. At the measured frequency, performance is pretty good: P1dB = 33 dBm, 17.5 dB of gain, 2 dB higher NF than the former option. I'd want to test this device before implementing it on the board, as we'd be taking a risk using it at its lower end. - TQP7M9106 <https://www.mouser.com/datasheet/2/412/QP7M9106-1500761.pdf>: They really flaunt the high linearity and bandwidth of this amplifier, but it does have acceptable characteristics at the desired frequencies. Noise figure is around the same as the first option, and current consumption is between the other options. I'm leaning towards the GRF5504 since it seems the most suited for the application, but maybe I'm wrong. There aren't a lot of good options in the 70 cm band. I can test it against a discrete amplifier on our PA test board. I know we're sharing the antenna module with FOX+. Does anyone know how we're switching the resource to the antenna? Perhaps that's a question for the ICD manager. I wanted to suggest using MEMS switches since they're more reliable and take up less board space. We use them at work for our serializer channel switches. I'm not sure how they'll hold up at 2W, but they've proved better than relays in almost every sense. Here <https://www.mdpi.com/1424-8220/24/10/3135> is a report on MEMS switches for antenna switching for space applications. I also wanted to mention that I wrote a report <https://docs.google.com/document/d/1N9ZAk-9m667yN1V_LVc1hHOa87ftJdjcrTFCgRI…> on possible AX5043 replacements (not for an AMSAT group). I know it's not at the top of the list of things to do, but it might be a starting point for someone. Thanks! Cameron ------------------------------------------------- Cameron Castillo KJ7ILB *P*: (503) 752-8877 --------------------------------------------------

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Recognition of our Engineering Team
by Bill Reed 20 Sep '24

20 Sep '24

Email from Jerry........ On Wed, Sep 18, 2024, 2:28 PM Jerry Buxton via Golft <golft(a)amsat.org> wrote: Hi All, I would like to put a face on Engineering for our BOD and in the Engineering presentation, at Symposium. For that I would really like to have a photo of everyone, a "closeup" of their face as in the likes of a business profile or resume or otherwise what you use for public presentation of yourself. If you are like me, where I've not had a photo of that type other than my DL or passport (although my DL is actually pretty good!), then a selfie or a photo taken by your spouse or friends or kids in the style I think you get the idea from the description, is good too. To gather this up as quickly and correctly as I can I am asking that you reply directly to me, vpe(a)amsat.us, from this email or a separate email with the subject "Recognition of our Engineering Team" so that my email can sort them into a separate folder. Include the photo of course, and original size no matter the filesize is best for clarity in whatever form I'll use it. Also please include in your email reply: First and last name (as you like to be called, e.g. "Jerry" vs. "Gerald" Your U.S. callsign, and if you have another country include that too The system(s) you are working on in terms of the "major" piece such as EPS, ADCS, SDR, IHU and the "piece of the whole", GPS for ADCS/IHU for example, if applicable The overall project(s) you are involved in such as GOLF, Fox-Plus, and in the case of ASCENT the name of the ASCENT project (e.g. SDR-B) - All of this so I don't miss something or otherwise screw it up in trying to remember what everyone does, there are a lot more things going on here than ever before! I'm not sure the level of detail I can go to but if I have that all, the more the merrier in what I can use to present the importance of this Team to AMSAT as a whole. If you have questions or want clarification in what I'm asking, bring it up on the call tonight and we'll spend a few minutes so it might answer the question for everyone. Thank you! -- Jerry Buxton, NØJY Vice President - Engineering Radio Amateur Satellite Corp. (AMSAT)

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Pacsat dev mtg 9/19/2024
by Bill 20 Sep '24

20 Sep '24

Pacsat dev mtg 9/19/2024 Thu, Sep 19, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/348562589 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (408) 650-3123 - One-touch: tel:+14086503123,,348562589# Access Code: 348-562-589 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 348 562 589 Or dial directly: 348562589(a)67.217.95.2 or 67.217.95.2##348562589 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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Issues interfacing to Launchpad
by Bob Stricklin 13 Sep '24

13 Sep '24

Alex and Chris, Here is some older discussion I feel is the same issue you are having. Your Windows 11 OS does not recognize the Launchpad development system. The USB interface on the LaunchPad is designed to work like a TI XDS110 programmer. This programmer is placed on the launchpad board. You can review this thread for some info on what to do. If you post a note on the TI support system you may get the help needed to correct the problem. They tend to support universities well. Sorry you are having so much trouble. https://e2e.ti.com/support/tools/code-composer-studio-group/ccs/f/code-comp… To make windows work properly with the TI interface TI had to do development work with Microsoft and provide the needed signatures to allow the USB interface. I have done this in the past and it is not easy so TI may not of taken the time or paid for support to get it done. The USB signatures are used to improve security. If you can find an older computer I5, I7 or other type it would be possible to load Ubuntu linux on the computer and the TI development software to use this in your lab. I know you would have some issues to work thought the computer management folks at the university but Linux is so widely used in research now days I would think they are up to speed on this. I can support you on how to do this if you take this path. Bob

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Pacsat dev mtg 9/12/2024
by Bill 13 Sep '24

13 Sep '24

Pacsat dev mtg 9/12/2024 Thu, Sep 12, 2024 7:00 PM - 9:00 PM (CDT) Please join my meeting from your computer, tablet or smartphone. https://meet.goto.com/831161669 You can also dial in using your phone. (For supported devices, tap a one-touch number below to join instantly.) United States: +1 (224) 501-3412 - One-touch: tel:+12245013412,,831161669# Access Code: 831-161-669 Join from a video-conferencing room or system. Dial in or type: 67.217.95.2 or inroomlink.goto.com Meeting ID: 831 161 669 Or dial directly: 831161669(a)67.217.95.2 or 67.217.95.2##831161669 Get the app now and be ready when your first meeting starts: https://meet.goto.com/install

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More Launchpad issues
by Blumenthal, Alex 10 Sep '24

10 Sep '24

Hi all, I was finally able to sit down and work on the Launchpad a bit more this morning. Here's a description of the problem I'm currently running into. When I do a power cycle (unplug and plug it back in), the computer recognizes the device as a USB connection and automatically assigns a com port. The code complies nicely in CCS with few to no errors. When I try to run the code on the board, CCS says that the current firmware version of 3.0.0.29 must be updated to 3.0.0.31. When I try to update the firmware through CCS, the console says "updater failed to connect to the XDS110 in programming mode." I tried to update the firmware manually through command prompt. I typed the following commands as indicated in the manual: xdsdfu -m xdsdfu -f firmware_3.0.0.31.bin -r After typing the 1st command, the device is supposed to go into DFU mode. The computer gets rid of the USB connection with com ports and now shows a new connection called "Tiva Device Firmware Update." In the Device Manager, this shows up under "Other devices" with the yellow triangle. After typing the second command, I get a response saying that "the requested device was not found on the bus." Any thoughts on how to proceed? Sincerely, Alex

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