FM APRS

[VK3KYY]

I just got out and tested my RD-5R to my Kenwood D710A in my car and it got picked up and decoded correctly on it. Yee-ha!

I'll test the longer distance to the iGate soon when I am more out in the open.

Thanks for everything and sorry for the confusion. I am reporting this in my car on my phone, but I am safely parked with the engine turned off.

Cheers,

OK.

I do test any new functionality on the GD77, DM-1801, RD-5R, RT3S, DM-1701 and MD-9600.

Also some beta testers have some of these radios, but its up to them which radios they have time to test it on.

Its not going to work on the GD77S because this radio does not have a GPS and because it doesnt have a keypad the location can't be entered into the radio.

[VK3KYY]

Would it help if the CPS can have the location data and then program the radio along with the code plug writing? And especially when there's location API in Windows that can source that data from the OS, making it even simpler for the end user? Just thinking out loud，not really a request for more work for you.

This seems pointless, except for the GD77S, becuase the whole point is that you have to enter the specific location of the radio.

Also, the Windows .NET location API is highly inaccurate for normal operation on a PC

Location information may come from multiple providers, such as GPS, Wi-Fi triangulation, and cell phone tower triangulation

And as the PC does not have GPS, or Wifi triangulation or cell connection, this won't work.

IP lookups are even worse, even on my mobile phone, as my telecon provider is actually not even located in Australia where I live.

The problem is when people post things like

And especially when there's location API in Windows that can source that data from the OS"

other people assume this information is correct.

We then have to waste time explaining why we can't do this, becuase the information is wrong.

[VK3KYY]

I think I have made too many posts lately and I'll stop and reflect upon myself and my behavior from now on.

(My Panasonic Tough Book has both GPSr and a LTE cellular modem, by the way ).

I am not an idiot. I have studied electrical engineering and computer science at a state university in California. Licensed since 1993, but have been already playing with radios and electronics for more than 10 years before that, since I was a kid. Have been active since then.

I have worked in IT for over 30 years. Sure my coding skills have been returned back to my profs because I changed careers early. When I took the C language course, the text was Kerninghan and Richie (could be a spelling mistake), ANSI C draft version.

Wow, so yes, don't waste time responding to my posts or correcting them. I will stop posting.

I have received your request to delete you account,

Username: ve7mdt
Profile: memberlist.php?mode=viewprofile&u=232


Message sent to you follows
~~~~~~~~~~~~~~~~~~~~~~~~~~~

I will no longer be in the discussion and wish to be taken off the membership.

Thanks for all the great discussions in the past and all the best to the devs and the community .

73,

So as per your request you account has been deleted and hence all your posts have also been deleted.

If anyone quoted your text however this will remain as text people have in their posts, including quotes are not linked to your account

[ZL4JOCO]

I think I have a BUG Report for the early APRS FM functionality. Very cool to see this starting to move on this hardware.

I have been testing using my MD-UV390 and comparing what I am seeing on the repeaters raw logs.

This line from my pi-star hotspot's APRS setup:

Code: Select all

2023-08-17 21:27:31 NZST: ZL4JOCO-D>APDG03,qAS,ZL4JOCO:>Powered by W0CHP-PiStar-Dash (https://wpsd.w0chp.net)

This sent from the MD-UV390

Code: Select all

2023-08-17 21:31:40 NZST: ZL4JOC-9>APN001,ZL2WA-3*,WIDE2-1,qAR,ZL2RCL-1:!4106.45S/17454.26E! OpenGD77

Notice that the callsign is being truncated under opengd77 to a length of 6 when (at least in NZ) 7 is a valid length. In my case a callsign of ZL4JOCO

Thanks - James.

[VK3KYY]

I think I have a BUG Report for the early APRS FM functionality. Very cool to see this starting to move on this hardware.

I have been testing using my MD-UV390 and comparing what I am seeing on the repeaters raw logs.

This line from my pi-star hotspot's APRS setup:

Code: Select all

2023-08-17 21:27:31 NZST: ZL4JOCO-D>APDG03,qAS,ZL4JOCO:>Powered by W0CHP-PiStar-Dash (https://wpsd.w0chp.net)

This sent from the MD-UV390

Code: Select all

2023-08-17 21:31:40 NZST: ZL4JOC-9>APN001,ZL2WA-3*,WIDE2-1,qAR,ZL2RCL-1:!4106.45S/17454.26E! OpenGD77

Notice that the callsign is being truncated under opengd77 to a length of 6 when (at least in NZ) 7 is a valid length. In my case a callsign of ZL4JOCO

Thanks - James.

AFIK. I this is a limitation of the AX25 packet protocol

See

http://www.aprs.org/doc/APRS101.PDF

section 3 APRS AND AX.25

Source address is 7 bytes, but the last byte is the SSID number

Source Address — This field contains the callsign and SSID of the transmitting station. In some cases, if the SSID is non-zero, the SSID may specify an APRS display Symbol Code.

So, as I read the spec, APRS / AX25 packet can only handle 6 character callsigns.

Perhaps you can ask some more ZL's about this.

BTW. is it normal for ZL's to have 7 letter callsigns.

Australis did have 7 letter callsigns for foundation licences , e.g. VK1FABC where the F indicates foundation

But from what I can remember the 7 letter callsigns were phased out for new allocations, becuase of the problem with many systems not handling 7 letter calls, ie its not just AX 25, I think some other digital modes don't handle it.

https://www.acma.gov.au/changes-amateur ... ign-policy

[SA0BUX]

Seems to max 6 character according to this discussion too

https://www.reddit.com/r/DMR/comments/i ... to_fit_in/

You could put your callsign in the comment field.

[ZL4JOCO]

Thanks. So the other line coming from the hotspot is "correct" becuase its going via internet connection and thus bypasses the AX25 limits?

Cheers - J.

[SA0BUX]

Thanks. So the other line coming from the hotspot is "correct" becuase its going via internet connection and thus bypasses the AX25 limits?

Cheers - J.

Yes, that's APRS-IS

[VK3KYY]

Thanks. So the other line coming from the hotspot is "correct" becuase its going via internet connection and thus bypasses the AX25 limits?

Cheers - J.

The Hotspot does not use AX25.

DMR uses 24 bit numbers for the source and destination address. The numbers are resolved to callsigns by the data from RadioId central register of callsigns

DMR in band / in call / "Talker Alias" data can also carry plain text, e.g. the callsign, and is longer than 7 characters, but off the top of my head, I can't remember how may characters it can handle

MMDVM hotspots, eg running MMDVMHost on a Rpi, read the source and destination address form the DMR bitstream (LC Headers) and wrap the raw DMR bitstream with its own headers containing source and destination ID numbers and then send the raw data to the DMR server e.g. BM

The BM server only looks in the wrapper and not the bitstream data and then routes it accordingly

When receiving data from the internet MMDVMHost removes the header and send the raw bitstream to the Hotspot modem board, which buffers and then transmits the bitstream

[ZL4JOCO]

Thanks. That all makes sense. So from a proper identification and "destination" angle I presume you need to have a callsign that works in these rules or a secondary that will work? I'm thinking AX25/APRS and packet radio more broadly here. I'm new to all this so also trying to understand the conventions and "rules". Once of which is normaly "you shall identifiy yourself with you callsign".