Sound Card Packet  with AGWPE

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Most recent AGWPE version is:  2013.415  15 Apr 2013

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Packet Engine Pro

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USB SignaLink
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Further Reading

AGWPE and the SignaLink USB

Configuring AGWPE for one USB SignaLink Configuring AGWPE for two or more USB SignaLinks
Configuring the TX volume in Windows Troubleshooting AGWPE - USB SignaLink Problems   

Many AGWPE users have purchased Tigertronics SignaLink USB interfaces. There are other USB sound devices on the market that are probably equally as good! This page was not meant as an endorsement of the SignaLink over other devices. Rather it resulted from many questions about proper setup of the SignaLink with AGWPE. These tips may be useful for other USB devices as well.

The SignaLink and comparable products have interesting features of high value to AGWPE users. They:

  • Have a built-in "sound card" chip so AGWPE doesn't need to use your computer's sound card.
  • Use TX audio (VOX) to trigger your radio's PTT circuit -- doesn't need a serial or parallel port on your computer for PTT control.
  • Usse only a single USB cable from the device to the computer -- TX, RX and PTT cables from the computer are not needed.
  • do not need external power; the USB cable from the computer powers it.

1. Configuring AGWPE for One USB SignaLink

Be sure to read the SignaLink USB (SLU) documentation, especially the part about configuring the jumper wires inside the SLU to match your radio's pin-outs .

To create an AGWPE radio port for the SLU, first plug in the SLU's USB cable to your computer. Your computer should recognize a new USB device. (In my XP computer,  the Windows "connection" tones can be heard when this happens.)

Here is how I configured my AGWPE radio port for the USB SignaLink in Windows XP:

<-- click for a larger image of the Properties and SoundCard Modem/TNC Setup windows.

a. In the Properties for Port(x) window:

  •  for the Select Port field, select a non-existent LPT (parallel) port. Since the SLU does not require either a COM or LPT port for PTT control, there is no need for AGWPE to tie up a COM or LPT port on your computer. (I use LPT2.)  
  • Select Single Port to avoid any potential problems with cross-talk between the stereo audio channels.  
  • Name the Tnc RadioPort Port 1 something like  USB SignaLink. The name you select is only important in helping you recognize which "port" AGWPE is using in a multi-port configuration of AGWPE.)

b. Now press the Options button in the middle of the  Properties for Port1 window (colored red in the graphic above, but it will not be red in the program). This brings up the SoundCard Modem/TNC Setup window. In this window:

  • for the Right Channel OnAir BaudRate, select something other than 1200. This is done to avoid any potential problems with cross-talk between the stereo audio channels. (I use 2400.)  
  • at the bottom you will find the SoundCard Selection field. If necessary, use the scroll arrow to reveal and select the SLU's sound card, which is called USB Audio CODEC (on Windows Me /2000 systems it may be called USB Audio Device).

Then press OK to close all the AGWPE windows and restart AGWPE. The SignaLink USB should now be set to work with AGWPE.

2. Configuring AGWPE for Two or More USB SignaLinks

If you want to use two USB SignaLinks, you cannot use the the current version of AGWPE. You will need to use a pre-2010 version of AGWPE, but this will require some operating work-arounds (see below).

Earlier versions of AGWPE identified system sound cards by a number assigned by Windows. When detachable sound cards like the USB SignaLink came along, this presented a problem. The sound card numbering scheme was apt to change each time Windows rebooted depending on whether or not the USB SignaLink was plugged in during boot-up. (Since AGWPE saves each AGWPE port's sound card number when it closes, that sound card number may not match Windows' sound card number on the next boot.)

To correct this, the 2010 AGWPE version (and more recent) started to identify sound cards by the name of the sound card. This is a superior solution for one USB SignaLink. It doesn't matter what number Windows assigns the SignaLink. AGWPE will just use the name of the SignaLink as discovered by Windows, which is "USB Audio CODEC". This name is embedded in the USB SignaLink; no way is yet known to change it.

But a problem develops when two USB SignaLinks are found in the system. Both will identify themselves to Windows as "USB audio CODEC"s, and AGWPE won't be able to differentiate them. It will use the same SignaLink for both AGWPE ports or it may just crash.

The solution is to return to a pre-2010 version of AGWPE that uses the sound card numbering system. Windows will assign a different number to each USB SignaLink and AGWPE will be able to differentiate them. Note that the old problem of Windows assigning different numbers to each SignaLink after a reboot will then be possible. The best prevention for this is to plug both SignaLinks into the computer, reboot, and then re-configure the two AGWPE ports for the different SignaLinks. Now, try not to detach the SignaLinks from the computer between reboots. Hopefully, Windows will continue to assign the same number to each SignaLink and the AGWPE port configuration files will match those numbers.

3. Configuring the TX volume in Windows

Use the Windows Volume Control program to control the SLU's TX audio levels. If volume is insufficient, the SLU will not transmit.  Follow the instructions on the Sound Card settings page of this web site, but set the Speaker slider for the USB Audio CODEC to 100% and set the Wave slider to about 75%.

<-- Click on small image to download larger image

Note: If necessary, there is also a special jumper setting inside the SLU to further increase TX audio levels; see the SLU Installation and Operation Guide for information about this. When using the Volume Control program, be sure you are setting the volume controls for the SLU's card (USB Audio CODEC card) and not some other sound card in your system. Note that the name of the sound card you are adjusting is in the bottom line of the Volume Control window. If USB Audio CODEC is NOT displayed, use the window's menu, specifically Options: Properties: Mixer Device, to select the USB Audio CODEC:

<-- Click on small image to download larger image


4. Troubleshooting AGWPE - USB SignaLink Problems

For Vista and more recent versions of Windows, a special work-around is required for SignaLinks and other external sound devices. Please visit the Renaming a Sound Card page.

The SignaLink USB (SLU) Installation and Operation Guide contains detailed information about recommended SLU settings and troubleshooting.  There is also a website which has troubleshooting information

Here are just a few key items to check if you have difficulties:

a. Make sure there is power to the SLU

  • Verify that the SignaLink USB’s green PWR LED is illuminated. If it is not, then make sure that the SignaLink USB's red PWR switch is pressed in and the USB cable is securely connected to the computer and the SignaLink.  
  • If the SignaLink is plugged into an external USB hub, verify that the hub is a powered hub and is getting external power. Non-powered hubs may not supply enough power for the SignaLink to operate properly (Receive will work, but Transmit may not).

b. No Received Audio in the AGWPE Sound Card Tuning Aid.

  • The RX audio dial on the front of the SLU is the only way to increase or decrease the RX audio levels (unless you are getting the RX audio from the speaker of your radio, in which case your radio's volume control dial will  effect the RX audio level going to the SLU). I've had good success with the RX audio dial on the SLU set to the 9 o'clock position.

Other sound cards use the Windows Volume Control Recording sliders to adjust RX volume levels. There is no such control for the SLU; likewise the RX control sliders on AGWPE's Sound Card Tuning Aid screen have no effect on the SLU's RX Audio levels. The SLU's receive audio can not be adjusted by software (AGWPE or Windows); only by the RX audio dial on the front of the SLU.

  • You may have incorrectly installed the RX jumper wires inside the SLU. Recheck that the SPKR jumper is set to go to the correct pin on your radio (RX audio/AF out/speaker/audio out/1200 output/data out/output/PR1) ; or if your radio does not provide RX output at its MIC, DATA or ACCY jack, then plug in a wire from the radio's speaker jack to the SPKR jack on the back of the SLU. See the USB Installation and Operation Guide for detailed information.

c. The SLU/radio does not transmit:

  • If the SignaLink USB's red PTT LED does blink but the radio doesn't switch to transmit, then you have most likely incorrectly installed the PTT jumper wires inside the SLU. Recheck that the PTT jumper is set to go to the correct pin on your radio -- PTT/send/PKS. (Note: in some radios, the PTT pin for FM packet is different from the one used for SSB audio modes such as PSK-31, RTTY and SSTV; if this is the case, you may need a different cable or jumper setting for packet use of the SLU with that radio).  
  • If the SignaLink USB's red PTT LED does NOT blink, then TX audio from the computer to the SLU is too low or non-existent. Try these fixes:  
    • Make sure you are using AGWPE version 2013.415 or later. Earlier versions were not always able to correctly find the USB Audio CODEC/SLU sound card from session to session. If you are using Windows Vista, 7, 8 and newer: Please see the Problems with Transmitting page, item #1  
    • Make sure AGWPE is configured to use the SignaLink USB’s built-in sound card. The program should have USB Audio CODEC selected (or it may be called USB Audio Device on Windows ME/2000 computers). See 1.b above, Configuring AGWPE for the SignaLink USB.  
    • The SLU must be plugged into a USB port before you start AGWPE; Windows must recognize that the SLU is plugged in before you start AGWPE. You can't plug the SLU in after AGWPE starts and expect it to work. (If AGWPE can't find the USB Audio CODEC (SLU) when it starts, if will instead try to use your computer's default sound card.)  
    • Recheck the Windows' Volume Control settings for the USB Audio CODEC: see #2 above. The Windows' TX audio volume must be high enough to trip the SLU's VOX circuit.  

d.Connections Not Established or Maintained

Set the DLY (Delay) dial on the front of the SLU to the 7 o'clock position (fully counterclockwise). This minimizes the time the SLU keeps your radio in transmit mode. If you increase the delay, the packet station which you are communicating with may begin to transmit before the SLU returns to "receive" mode and you will not receive the first packet from the distant station.

e. Other stations don't seem to hear my packets

The TX audio dial on the face of the SLU should normally be set to the 9 or 10 o'clock position. The TX dial controls the audio level of your outgoing packets. If it is set to low or too high, your target station may receive a packet that is too weak (low) or perhaps distorted (high). Ideally, the audio should be set to the lowest level that results in packets still being decoded reliably by the target station.

f. When AGWPE transmits, I hear packets in my speaker

Probably the SLU was not plugged into the computer when AGWPE started. As a result, AGWPE did not find the SLU and is using the default sound card in its place. To fix this, close AGWPE, make sure the SLU's USB cable is plugged into the computer, and restart AGWPE. In some systems, you may need to reboot Windows with the USB cable in place.

g. When I'm using other (non-packet) programs, sometimes the SLU will transmit!

 You probably have the SLU configured as your default sound card. As a result, sounds from these other programs are routed to the SLU and it will try to transmit them! To fix this, you need to make the default sound card something other than the SLU.  You can do this by going to the Windows Start Button; then Settings: Control Panel; Sounds and Audio Devices (or something similar in non-Windows XP systems). Select the Audio tab and then under Sound Playback: Default Device, use the scroll down arrow to reveal a list of sound cards. Pick something other than USB Audio CODEC for your default playback device.

<--  Click on small image to download larger image

h. The SLU's lights, but there's no audio on the transmission (or other stations don't appear to hear me)

Check the jumpers inside the SLU. Although audio from the computer is making it to the SLU, it's likely that it is not making it to the radio. Recheck that the MIC jumper inside the SLU is set to go to the correct pin on your radio (TX audio/AF in/mic/mic input/audio in/data in/aux in/mod in/PKD).

i. Vista/Windows 7

1. Make sure you use AGWPE version 2010.814. You can download it from this website (it may not be on the SV2AGW website):

2. Install it in a folder NOT under C:\Program Files, for example, use C:\Ham or another folder of your choice.

3. Follow these tips from Mike KJ4SNT and make a name change for the SLU in Windows. :

"After the upgrade to Windows 7, the SignaLink was not working properly. I was able to receive properly, but I was not able to transmit. The transmit signal would come out of my desktop speakers.

I noticed that the Windows 7 OS gave the microphone and the speaker for the SignaLink two different names by default.

The receive was labeled "Microphone 2 - USB Audio CODEC" and the transmit was labeled "Speakers 2- USB Audio CODEC".

I changed BOTH the microphone and speaker name to be the EXACT same text. Now both are called "SignaLink". This seems to be the critical piece that was missing.

Changing the names of the microphone and speakers is done by starting the control panel->hardware and sound->sound then right clicking on the device to rename, picking properties, and then changing the name above the "Change Icon" button.

Hopefully this saves someone else a few hours.

I was not able to make this work with the PE Pro version. My AGWPE version is 2010.814, but I am reasonably confident it will work with the prior version."


There are other reasons why the station may not hear you, mostly relating to poor signal quality. Go to the Problems with Transmitting page or the Problems with Connections page for more hints.

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