FM APRS

[VK3KYY]

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".

The "you shall identifiy yourself with you callsign" parts of most radio licenses, don't seem to have kept up with technology

No one sends their callsign when using DMR. They send a number which you can resolve to a callsign by looking it up in the appropriate database.

In general digital radio signals can't be decoded without the required hardware or software.

There are loads of signals on Ham Radio bands that I can't decode because I don't have D-STAR or NXDN or P25 radios
Additionally there are home brew standards like M17 which various groups made up themselves and are not international standards, like DMR is via its ETSI standard.

I presume I can make my own M18 mode / standard if I want, I presume if I publish my data protocol it would be OK for me to use this mode

But possibly each licensing authority keeps a list if digital modes that people are allowed to use, but I think most licensing authorities don't have the resources to do this.

[ZL4JOCO]

Have been doing tests with UV390 and latest firmware as at time of this post. Messages getting through to the digirepeater and I can see them in its logs. As expected call sign truncated per AX.25 spec. But 2nd callsign that matches the truncation is being lodged (thankfully its available).

I have tried similar tests using the MD9600 and not having any luck. Is P1 the button I quickly push when PTT is pressed to get the transmit? Since no sound I normally do a 1-2sec count to ensure it works. As an idea for the MD9600, if we can get sound then could there be some symbol on the display that appeard then disappeared? Of course if things are still in flux for a greater end goal then probably not worth the effort.

Speaking of "greater end goal" for the APRS FM mode, is there one described somewhere?

Cheers - J.

[VK3KYY]

Using the MD9600 and not having any luck. Is P1 the button I quickly push when PTT is pressed to get the transmit? Since no sound I normally do a 1-2sec count to ensure it works. As an idea for the MD9600, if we can get sound then could there be some symbol on the display that appeard then disappeared? Of course if things are still in flux for a greater end goal then probably not worth the effort.

Speaking of "greater end goal" for the APRS FM mode, is there one described somewhere?

Cheers - J.

MD9600 uses P2 for SK2 not P1

Also, as previously posted to the Beta announcement, there is currently a problem with the deviation level on the MD-9600 for APRS and 1750Hz 'tone burst' and also a frequency offset problem on both of these modulations

I have a fix for this and its currently undergoing testing

Also. As documented in the User Guide. The MD9600 is currently unable to send the comment field because of a hardware limitation in the C6000 chip tone generator
I hope to eventually be able to work-around this problem, but the solution requires many hours of work and I have sooooo many other things I need to do on all these radios

As an idea for the MD9600, if we can get sound then could there be some symbol on the display that appeard then disappeared?

All radios, including the MD9600 , already do this.

We can't currently make any beep on the MD9600 while its transmitting APRS becuase the processor is tied up sending the 1200baud and there is no hardware AF signal path to the speaker, that we are aware of, on the MD9600

A similar issue exists at the moment on the DM-1701 , even though the hardware is different to the MD-9600, becuase it aslo lacks an audio path from the tone generator to the speaker.

[ZL4JOCO]

Thanks.

I thought it was SK1 like on the UV380/390. I must have missed that it’s SK2 for MD9600. That would explain things not working.

On transmit, to clarify as rereading my last post my ask was poorly defined. Is there a visual indicator on the MD9600 screen when the modem tone is being sent? I’m out of town for 3 days, but will have an experiment on Friday to see if I can see anything.

I understand the h/w limitation re being able to hear the tone. So wasn’t expecting that.

I do recall you description of how you could around the limits that stopped the comments txt from being part of a continuous transmission. 50hrs work rings a bell! While Im sure many of us would like that cracked (along with for example a timer based gps position transmit ) it’s your time and you get to it if/when you get to it.

Again, thanks for the responses.

Cheers - James.

[VK3KYY]

Thanks.

I thought it was SK1 like on the UV380/390. I must have missed that it’s SK2 for MD9600. That would explain things not working.

MD-9600 button mappings are well documented in the user guide

https://github.com/LibreDMR/OpenGD77_Us ... 0-specific

Is there a visual indicator on the MD9600 screen when the modem tone is being sent

Yes. Like the other radios the screen shows "APRS"

[ZL4JOCO]

Thanks. Yes I know the documentation and hence why I pushed P1 for SK1 as I was pushing SK1 on the UV390 to send the APRS signal. What I was not aware was that you need to push P2 for SK2 on the MD9600. It never occurred to me the process would be different. Is this cose you have access to SK2 on the handset and not SK1?

Re the APRS on screen had never noticed that on the HT after multiple uses. Mind you I was holding it up high in a particular part of the garden to get the transmission through. Now I have a flower pot antenna built it should be easier to watch displays while pushing buttons and getting signals through. Will look when back home on Friday.

Thanks - James.

[VK3KYY]

Thanks. Yes I know the documentation and hence why I pushed P1 for SK1 as I was pushing SK1 on the UV390 to send the APRS signal. What I was not aware was that you need to push P2 for SK2 on the MD9600. It never occurred to me the process would be different. Is this cose you have access to SK2 on the handset and not SK1?

Re the APRS on screen had never noticed that on the HT after multiple uses. Mind you I was holding it up high in a particular part of the garden to get the transmission through. Now I have a flower pot antenna built it should be easier to watch displays while pushing buttons and getting signals through. Will look when back home on Friday.

Thanks - James.

The documentation for the MD9600 reads:

Key Function
P1 SK2
P2 SK1
P2 (NO FUNCTION)
P4 Star (*)

NOTE.

P1 IS SK2 NOT SK1

[SA0BUX]

Thanks.

I thought it was SK1 like on the UV380/390. I must have missed that it’s SK2 for MD9600. That would explain things not working.

MD-9600 button mappings are well documented in the user guide

https://github.com/LibreDMR/OpenGD77_Us ... 0-specific

I see some conflicting information in the guide.

MD9600-1.PNG (249.37 KiB) Viewed 1274 times

MD9600-2.PNG (9.1 KiB) Viewed 1274 times

[VK3KYY]

OK.

I don't know who made the picture.

Daniel is now fixing this inconsistency

[VK3KYY]

Daniel has now fixed this inconsistency