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Re: AX5043 deafness
by Rich Gopstein 28 Apr '23

28 Apr '23

For fun, you can check the RSSI while receiving on both bands. Might tell you something... On Fri, Apr 28, 2023 at 12:04 PM Jim McCullers via pacsat-dev < pacsat-dev(a)amsat.org> wrote: > Chris, > > > > I assume you are referring to packets you are generating locally. > > I’ve only tested with the Pi boards and noticed no difference with locally > generated signals between the 70cm board and the 2-meter board after > getting the frequency correct. > > My 2-meter Pi board appear a bit deaf on signals from the local APRS > digipeters. > > > > Guess I need to get the LaunchPad set up. > > > > I’ll review the schematic on the daughter board but the schematic should > be identical to the Pi schematic. > > > > Let me explore. > > > > 73 > > > > Jim > > > > Jim, > > > > I have the AX5043 working on 145.835. It ranges correctly and receives > packets. At least it receives them some of the time. It seems to be quite > deaf compared to wje it was working on 436.8, which is my 70cm RX > frequency. That receives every packet without error. > > > > I had the same issue on 70cms until you told me to tweak the frequency. > But with the TXCO it seems to be right on frequency. I ran a test to TX on > the RX frequency and it seems to be correct according to my TinySA. > > > > thoughts? > > > > 73 > > Chris > > > > -- > > Chris E. Thompson > chrisethompson(a)gmail.com > g0kla(a)arrl.net > > ----------------------------------------------------------- > > 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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Re: AX5043 deafness
by Jim McCullers 28 Apr '23

28 Apr '23

Chris, I assume you are referring to packets you are generating locally. I’ve only tested with the Pi boards and noticed no difference with locally generated signals between the 70cm board and the 2-meter board after getting the frequency correct. My 2-meter Pi board appear a bit deaf on signals from the local APRS digipeters. Guess I need to get the LaunchPad set up. I’ll review the schematic on the daughter board but the schematic should be identical to the Pi schematic. Let me explore. 73 Jim Jim, I have the AX5043 working on 145.835. It ranges correctly and receives packets. At least it receives them some of the time. It seems to be quite deaf compared to wje it was working on 436.8, which is my 70cm RX frequency. That receives every packet without error. I had the same issue on 70cms until you told me to tweak the frequency. But with the TXCO it seems to be right on frequency. I ran a test to TX on the RX frequency and it seems to be correct according to my TinySA. thoughts? 73 Chris -- Chris E. Thompson chrisethompson(a)gmail.com <mailto:chrisethompson@gmail.com> g0kla(a)arrl.net <mailto:g0kla@arrl.net>

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AX5043 deafness
by Chris Thompson 28 Apr '23

28 Apr '23

Jim, I have the AX5043 working on 145.835. It ranges correctly and receives packets. At least it receives them some of the time. It seems to be quite deaf compared to wje it was working on 436.8, which is my 70cm RX frequency. That receives every packet without error. I had the same issue on 70cms until you told me to tweak the frequency. But with the TXCO it seems to be right on frequency. I ran a test to TX on the RX frequency and it seems to be correct according to my TinySA. thoughts? 73 Chris -- Chris E. Thompson chrisethompson(a)gmail.com g0kla(a)arrl.net

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Interrupts on the PACSAT software
by Burns Fisher (AMSAT) 28 Apr '23

28 Apr '23

Chris asked me about adding an interrupt in the PACSAT software. I answered him, (the answer is the same for PACSAT and Golf) but then realized that this is probably not well documented anywhere. So for now, I cut and pasted the email to him and put it in a document in PacSatDocs/refernce (since it is originally a Golf and even Fox thing, I'll put the source there eventually). This is not an emergency for you to read unless you are adding GPIOs or interrupts. It sounds complex, but it is sort of a reasonably simple abstraction of GPIOs and interrupt that works on both the LIHU and the RT-IHU. The complexity comes because the two processors not only interrupt stuff that is quite different from each other, but not really the same as the abstraction itself! 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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Re: Inductor
by Jim McCullers 28 Apr '23

28 Apr '23

Thanks Chris. I don’t have any 91s here in any size and will get an order on the way. I need an extra header as well to replace one that didn’t go well. I’ll mail Burns one or two with plenty of tape so that they won’t get lost in the envelope. That will delay the shipment of the final board but good catch. Thanks. My Jonathan board ranged well with a 100nh and I forgot the very early discussion on the 91nh. 73, Jim McCullers WA4CWI Jim, I changed the inductor to 91nH and now it ranges from 137MHz to 151MHz. Seems good. I agree from your other email that the exact value will be dependent on the layout of the final board and stray inductance etc. BTW, I didn't have the 91nH in the right size (only 82 and 100). So I had to squish in the next size up. But that seems to work. 73 Chris -- Chris E. Thompson chrisethompson(a)gmail.com <mailto:chrisethompson@gmail.com> g0kla(a)arrl.net <mailto:g0kla@arrl.net>

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Re: Inductor
by Burns Fisher (AMSAT) 28 Apr '23

28 Apr '23

Speaking of "the next size up", Rich, in testing with the "Jonathan board" actually hand-wound an inductor with something like #22 wire around a pencil. I tried to do that and solder it on, but had no luck. Even that wire is huge compared to the pads :-) 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software* On Fri, Apr 28, 2023 at 9:26 AM Chris Thompson via pacsat-dev < pacsat-dev(a)amsat.org> wrote: > Jim, > > I changed the inductor to 91nH and now it ranges from 137MHz to 151MHz. > Seems good. I agree from your other email that the exact value will be > dependent on the layout of the final board and stray inductance etc. > > BTW, I didn't have the 91nH in the right size (only 82 and 100). So I had > to squish in the next size up. But that seems to work. > > 73 > Chris > > -- > Chris E. Thompson > chrisethompson(a)gmail.com > g0kla(a)arrl.net > > ----------------------------------------------------------- > > 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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Inductor
by Chris Thompson 28 Apr '23

28 Apr '23

Jim, I changed the inductor to 91nH and now it ranges from 137MHz to 151MHz. Seems good. I agree from your other email that the exact value will be dependent on the layout of the final board and stray inductance etc. BTW, I didn't have the 91nH in the right size (only 82 and 100). So I had to squish in the next size up. But that seems to work. 73 Chris -- Chris E. Thompson chrisethompson(a)gmail.com g0kla(a)arrl.net

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Re: Serial line on pacsat
by Corey Minyard 27 Apr '23

27 Apr '23

On Fri, Apr 28, 2023 at 01:29:19AM +0000, Burns Fisher (AMSAT) via pacsat-dev wrote: > 1) The pins to use on the launchpad are j2 pin 3 (RX) and 4 (Tx). Nearby, > J3 pin 2 is ground. Note that each row is a different "J" number on the > board, and the count 1,2,3 etc from the USB connector end. Jim numbered > them on his schematic somewhat more sensibly, but they don't match the > board. Looking at the launchpad schematic, are you sure that's not J3? -corey

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Serial line on pacsat
by Burns Fisher (AMSAT) 27 Apr '23

27 Apr '23

1) The pins to use on the launchpad are j2 pin 3 (RX) and 4 (Tx). Nearby, J3 pin 2 is ground. Note that each row is a different "J" number on the board, and the count 1,2,3 etc from the USB connector end. Jim numbered them on his schematic somewhat more sensibly, but they don't match the board. 2) This is not using the N2HET. It is using a regular SCI UART. 3) There is a lot of code that can be removed to reduce confusion, and someday I'll do that. The N2HET is not used at all. 73, Burns Fisher, WB1FJ *AMSAT(R) Engineering -- Flight Software*

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Re: AX5043
by Rich Gopstein 27 Apr '23

27 Apr '23

Just be aware that the Single-Ended pin is XMIT only. Only the differential pins can do both receive and xmit. Rich On Thu, Apr 27, 2023 at 6:26 PM Burns Fisher (AMSAT) via pacsat-dev < pacsat-dev(a)amsat.org> wrote: > Just FYI (and Zach may have comments) I don't know about differential > first not, but the fact that the 5043 and switch between them means that > the single ended output can be optimized for one band while the > differential can be optimized for another band. That's how one RT-IHU > processor can do either Rx or Tx (but not simultaneously) on two different > bands with the same 5043. > > 73, > > Burns Fisher, WB1FJ > *AMSAT(R) Engineering -- Flight Software* > > > On Thu, Apr 27, 2023 at 10:14 AM Jim McCullers via pacsat-dev < > pacsat-dev(a)amsat.org> wrote: > >> The bandpass filter and LNA would proceed this circuit. >> Most LNAs I'm familiar with are single ended output. >> Differential input is a bit of an oddity for an RF interface. I'm certain >> someone had a reason. >> >> In our instance we will have a bandpass filter followed by an LNA followed >> by a 1:4 splitter for the four receivers. >> Each receiver will require some form of single end to differential >> converter. >> >> 73, >> >> Jim McCullers >> WA4CWI >> >> >> >> On Thu, Apr 27, 2023 at 03:14:21AM +0000, Jim McCullers via pacsat-dev >> wrote: >> > Attached is a document that I prepared to describe work I've done with >> > AX5043 to create a receiver with a reduced component count. >> > >> > I'll post it to github later. >> >> Just curious, I'm not an expert on RF, but where does the LNA fit in here? >> It seems like you could do the conversion from single-ended to >> differential >> using an LNA if you were already using one. >> >> I've only played with single-ended designs, so this is something >> completely >> different for me. >> >> -corey >> >> >> ----------------------------------------------------------- >> >> 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 >> > > ----------------------------------------------------------- > > 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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