Setting the audio levels

Setting the Audio level for the different channels has a slightly different approach. UsbRadio and SimpleUsb have helper programs to assist with the tuning, and RpiRadio needs you to look at the Asterisk CLI and use some nous.

Chan_USBRadio Setup(Edit)

In the Main Setup Menu go into Upgrade/Add/Channels and Select USBRadio tune.

The following will pop up:

Tuning with DSP(Edit)

Tuning with DSP is easy. The program does most of the work!

  1. With the receiver in idle, and no signal, select option 2. If there is not enough noise and the test fails, adjust the 500k pot. When it is successful, go to the next step.
  2. Generate a fully quiet signal with a 123hz subtone (or whatever is set in usbradio.conf) at 500-600hz. If a service monitor is not available, use a portable with the deviation set to wideband. Press 4 and let the program adjust itself.
  3. Set a 1khz tone at 3khz deviation with the correct subtone fully quiet. If a service monitor is not available, set a portable to narrow deviation and give a whistle. Press 9. keep whistling until it says it has got the correct level (take a deep breath).
  4. Put the service monitor on rx. Press T to enable Transmitting. Press 6, follow the instructions to adjust the level to 3khz. If no service monitor is available, listen to a portable until it sounds like a nice signal.
  5. Press 8 and set the ctcss tone to 500-600hz on the service monitor. Leave it at a default if you do not have access to a service monitor.
  6. To test what it sounds like. Press E to enable Echo Mode. Transmit on a portable with the correct ctcss, and listen to youself and see it if sounds true audio.
  7. Press E to disable Echo, Press T to disable test transmit and press W to write the config.
  8. Press 0 to exit.

If you cannot whistle long enough for the node to pick up your audio, use option 3 and watch the display while you whistle. you should be able to see where it is going.

Non DSP tuning(Edit)

Follow the above procedure, however you do not need to set the RX noise level. Unless you are running DSP CTCSS rx is not really possible either.

SimpleUSB Setup(Edit)

SimpleUSB is just that, very simple. From the Main Setup Menu go into Simple USB Tune. The following will pop up:

  1. Generate a 1khz tone at 3khz deviation with a service monitor. Press 2 and follow the instructions. When you have it right, keep pressing enter until you end back at the Menu.
  2. With the service monitor in RX, Press T to enable the transmit testing. Press 3 and follow the instructions to set the TX level. If the level is not achievable, Alsamixer needs to be run to set the correct levels. In this case, leave the level at 500.
  3. Press W to write the settings and 0 to exit.

If you are unhappy with the levels, from the Main Setup Menu Select Run Alsamixer.

Here you can press F5 to bring up all levels, and use the keyboard to up and down the level. Before you go into the mixer, you can go into the asterisk cli and run the following command:

rpt fun {yournodenumber} *989

This will put your node into transmit with a 1khz tone at 3khz. You then go back into alsamixer and set the correct level on the service monitor, or what sounds nice from a portable. Press ESC to exit alsamixer and save the current levels

To stop the node from transmitting, go back into Asterisk CLI and run

rpt fun {yournodenumber} *989
to stop the tone.

Remember it is opposite to what you think. The speaker is the transmit of the radio.

RpiRadio Tuning(Edit)

As this is a very basic, very new channel, with bugger all features, tuning it is not as easy as the others. I suggest here that you open a second ssh or putty window to the node to do this procedure. There is no save feature yet, and all the tuning options are run from the Asterisk CLI.

  1. In one window, from the Main Setup Menu open the Asterisk CLI. Open AlsaMixer in the other.
  2. Set the service monitor to a 1khz tone at 3khz dev or whistle on a narrow dev radio. In the asterisk CLI, type:
    rpiradio tune rxd
  3. In the Alsamixer window, Adjust the Capture Mic level to reflect 3khz on the CLI display. When you are happy with this, cut the signal from the service monitor and type
    into the CLI window. A little bug I am yet to fix is the letters will repeat themselves in the one spot. This is why we are exiting the CLI.
  4. Go back into the CLI
  5. Put the Service montor into rx, in the CLI, type:
    rpt fun {yournodenumber} *989
  6. Adjust the level of the Speaker in the Alsamixer to reflect 3khz deviation, or what sounds nice on a portable.
  7. press {ESC} to exit out of the Alsamixer, type exit to exit out of the CLI.

Main page - Dynamic IP Addresses