Selecting Balanced XLR input

[K4IBC]

Selecting balanced XLR input.

Noticed this from another post.

Protocol 2, and with it Thetis or pihpsdr, have no settings to select the XLR balanced microphone input. In time maybe that can be added, but we'd have to check that the changes to the protocol had no effect onto other radios. In the short term in can be turned on manually with a command line option.

This may end up being a gotcha for people wanting to use this connector. Some of use are not Linux users. Maybe a simple batch file or desktop app to select the input would be user friendly at this time until it can be added to the software.

@laurencebarker can you give us the command line needed?

[laurencebarker]

Once the radio comes out and I know what software is loaded where, yes.

[laurencebarker]

OK, Saturn has a balanced microphone input. It cannot yet be selected from client applications like Thetis, but you can select it from the radio end.

To select the balanced input requires running the "p2app" program (that interfaces to remote clients like Thetis) with a command line option -m xlr. There are several ways to do that. Most people won't want to do the first one very often, but it is quick for testing.

1. Run the program from a command line: ./p2app -m xlr

2. Edit the P2app desktop icon so that it runs p2app with that option. Right click the desktop icon; select Geany; edit the text that appears in the editor to make the Exec line read as /home/pi/github/Saturn/sw_projects/P2_app/p2app -m xlr then save and exit

3. to change the version that is loaded at power up for "screenless" G2 models: there are instructions in the manual section 4.5 "running software automatically after power up". The second line in red text in the manual should say ./p2app -m xlr &


To connect a balanced microphone: it is wired to a 6.3mm stereo jack plug. You will probably need to make an adapter lead to an XLR female connector, or you may be able to buy one. This is described in the manual.


Why isn't this available in Thetis? Well it will need some effort, but it will probably happen eventually:
1. we'll have a make a change to protocol 2, and document it.
2. We'll have to make a radio-specific change to Thetis, to select the input. Radio specific code in Thetis isn't pleasant, and it will need to be re-tested for all other hardware to make sure it hasn't compromised other users' enjoyment.
3. Then p2app will need to be extended to support it (which is the easiest step).

[KC2QMA]

Just to be clear is there a 3pin XLR or Mini XLR connector on the back of the radio as shown in the photo on the website?

[KI4P]

Just to be clear is there a 3pin XLR or Mini XLR connector on the back of the radio as shown in the photo on the website?

I have not seen anything in the latest Manual to indicate anything about a mini xlr. It is kinda confusing about the connections on back. Manual picture shows a 3.5 trs but manual talks about a 1/4 inch on back?
Ki4p

[kc2rgw]

Seems it’s a 1/4” TRS jack.

[KC2QMA]

Seems it’s a 1/4” TRS jack.

So it's 1/4"TRS not XLR?

The manual says 6.3mm jack??

Now I'm lost....

[KA1GXR]

Seems it’s a 1/4” TRS jack.

So it's 1/4"TRS not XLR?

The manual says 6.3mm jack??

Now I'm lost....

1/4 " is 6.3 mm

[laurencebarker]

I don't yet have a photograph of it. If I did. it would already be in the manual. But where the prototype picture shows a mini XLR, the connector on the production unit is a 6.1mm stereo jack plug; or 1/4" jack plug in imperial units.

[KC2QMA]

I don't yet have a photograph of it. If I did. it would already be in the manual. But where the prototype picture shows a mini XLR, the connector on the production unit is a 6.1mm stereo jack plug; or 1/4" jack plug in imperial units.

OK Got it 1/4" or 6.35mm TRS female jack.
OK that's not so bad a 1/4" TRS is still a very good connection and widely used in the audio industry, much better than a 1/8"!

[K1LSB]

1/4" TRS is .... much better than a 1/8"!

Why do you say that?

Mark

[kc2rgw]

1/8” or 3.5mm jacks do not take any strain well at all. You basically need to strain relief them. If there is any pull they get bent easily and also they tend to lose contact as the jacks are often loose fitting where the greater surface area of the larger plug is more stable.

[KC2QMA]

I can not get the Balanced input to work with Thetis.

I edited the p2app application icon on the desktop for my G2 no panel as described using the -m xlr & commands and ran the app and it says “XLR Input Selected” so that’s good. But when I connect a dynamic mic to the TRS connector using a standard XLR to TRS cable I get no audio?
I tried to adjust Mic levels and even tried the +20db boost but no luck?

It looks like the p2app is set correctly but still no mic audio?

Is the TRS input a Mic level or Line level input?

[laurencebarker]

Did you terminate the instance of p2app that runs at startup? If not, it will be running too and it might be that one (which won't have the balanced input selected) which was found by Thetis.

There are instructions in the manual to terminate it.

Others have had the input working.

The tip/ring/sleeve of the adapter cable needs to be as per the manual - may be worth checking with a multimeter.

[KC2QMA]

After I added the -m xlr & command I saved and then restart the radio by powering down and up again.
I tried with and without the "&" symbol just to see if there was any diff.

Here are some pics if this helps.

As you can see the p2app is loading with the "XLR" enabled.

[laurencebarker]

That's not the same thing. I suspect you have TWO copies of p2app running - the first of which will not have -m xlr selected. You are editing the commands which leads to you running a second copy of the program, and the screen shots show that you have achieved that. BUT: you also need to terminate the first instance of p2app which ran when the operating system started up. It doesn't have a screen and doesn't show up on a display.

Please read the manual about how to "kill" the one that auto runs at startup. The manual also covers how to edit the settings of the version that auto-runs at power up so you could enable xlr.

(roughly speaking:

terminate the version you have started from the desktop
type ps -ax into a terminal window. This will show you a list of the processes running.
read through the list; I'm guessing you will find another ./p2app. On my computer its process id is around 700 but yours may be different.
note its process id (a numerical value)
type sudo kill <processid value> eg sudo kill 702

now run your desktop icon

[KC2QMA]

OK I ran pa -ax and the p2app # was 781
I typed sudo kill 781
Then clicked on the p2app and selected execute.
Opened Thetis and still no audio from balanced input?

I also tried the Line Input and no audio.
The only input that seems to work is the 1/8 mic input.

I'm starting to think I have a hardware issue.

[W7GES]

OK I ran pa -ax and the p2app # was 781
I typed sudo kill 781
Then clicked on the p2app and selected execute.
Opened Thetis and still no audio from balanced input?

I also tried the Line Input and no audio.
The only input that seems to work is the 1/8 mic input.

I'm starting to think I have a hardware issue.

Have you tried killing the p2app process, opening a terminal window cd to the correct directory and running the process manually with ./ps2app -m xlr?

It works for me that way with my G2-100 with screen. I haven't tried it via shortcut as explained in manual as I have been very busy.

73,

George / W7GES

[KC2QMA]

I have tried everything suggested but just cannot get the balanced TRS or Line Input to work?
Only the 1/8mic input on the back of the G2-100W no screen.

These are the steps I took:
-Ran ps -ax command
-found the # for the task (#781)
-Ran sudo kill 781
-Ran pa -ax to make sure that task 781 was “Killed”, It was.
-Then right clicked on the desktop icon “p2app” and clicked “Geney” to edit.
-Then I added to the end of the app’s path “-m xlr &” and clicked save.
-Then I double clicked on the “p2app” then clicked Execute.
-Looked at screen and it displays “XLR mic input selected” message in the list.
-Then rebooted the G2-100w and the started Thetis.

Still No audio from the TRS input.
Also the Line input doesn’t seem to work either?

Either I am not doing something correct in Linux witch is possible since I have no experience with the RaPI.
OR
Its a hardware issue, I took the cover off the radio and checked the wires going to the TRS jack and it looks correct (Red-Tip, White-Ring, Gnd-Sleeve) but I cannot verify any other connectors pinout without documentation on the boards.

I hope its just a software/firmware issue and that would not surprise me as there already is a multitude of audio issues with the new Saturn G2 radios. (No monitor audio, Initialization issues when opening and closing RX2 and others).

[Trucker]

Then I added to the end of the app’s path “-m xlr &” and clicked save

Is " -m xlr &" a typo?
The command in the manual doesn't include "&" in the line you would use to add the balanced input to p2app so that Thetis will use the balanced input.
James
WD5GWY

[Trucker]

Here's what the & symbol does.


If a command is terminated by the control operator &, the shell executes the command in the background in a subshell. The shell does not wait for the command to finish, and the return status is 0.

[laurencebarker]

I think you have now taken the correct steps.

[KC2QMA]

I think you have now taken the correct steps.

If you are addressing me Laurence what do you think my next steps should be?
John

[laurencebarker]

You could make progress investigating by looking at the manual for the "audiotest" application. This allows you to record audio from the mic inputs for a few seconds, then plays it back to you. It also shows a bargraph of signal level.

go to a command line and type:

cd github/Saturn/sw_projects/audiotest
make
./audiotest

(use file browser to resolve any issues with pathnames - I'm 7000 miles from home)

that little app will give gone good information about what the codec sees. You can select bias on/off, 3.5mm or XLR input from there. If you don't get good audio played back through that app it won't happen into a radio either.

did you check the cable connectivity?
what microphone do you have?

[KC2QMA]

The good news is the Audio Test app shows that audio is passing through the balanced input but the app locks up just after the test?

Here is a video to show the test:

[laurencebarker]

audiotest does hang sometimes, but not always. If I get some spare time one day I might try to fix that... but it has served its purpose - your hardware input is fine. It sounds as though there is a different problem with Thetis and I don't immediately know what it is.

[KC2QMA]

Maybe it's just Thetis and the G2-100 no panel model?
This may all be related to the other audio issues the G2 is having?

Anyway thank you very much for helping me with this issue at least we know the hardware is fine.
John

[laurencebarker]

No I suspect it is different from the other audio issues. Warren has traced those and a fix is being tested. There is nothing in the process that even knows whether the G2 hardware has a panel or not.

[KC2QMA]

Thank you again hopefully there will be a fix soon