MixW with N6CP

Requirements for MixW, according to the author:

• Processor: 486 CPU, 100 MHz minimum (Pentium 166 MHz or higher is recommended)
• Soundcard: 16-bit Windows-compatible
• RAM: 16 MB or more
• Hard drive: at least 3.5 MB free space
• Operating system: Windows 9x, ME, NT4, 2000, XP

Requirements for MixW, in reality:

• Processor: Greater than Pentium II (or equivalent)
• Soundcard: Any soundcard made since the year 2002
• RAM: 128 MB or more
• Hard drive: at least 20 MB free space
• Operating system: Windows XP

Radio Requirements:
CP2 uses a strictly FSK encoding technique to broadcast packets. When choosing our comm system, we compared different encoding techniques and found FSK to be the best encoding technique for our use. FM (with its strong carrier) is not feasible on the satellite because of power requirements (our power budget is less than 2 watts/day).

Due to this FSK modulation, earth stations cannot use regular FM receivers to listen to CP2. Earth stations must use the sideband detector of their radio. Since we are using such small frequency separation (standard 1200 baud packet), the sideband detector converts the two FSK frequencies to audio, and a TNC or software TNC can decode this data.

1. Download MixW here. This is version 2.12 and is 2.5 Megabytes. Save it to the desktop.
2. Double click the MixW212.exe file. This is a "standard installation" program.
3. Click at the welcome screen
4. Read the License Agreement, click on , and click
5. Save the files in the default location of C:\Program Files\MixW. Click
6. The installer will then install all the files needed for MixW to work. The installer will not touch the Windows Registry, so to remove MixW, just delete the entire folder. If you would like to delete the installer program, go ahead, but we reccomend that it be saved in case it needs to be re-installed at a later date.
7. MixW is now installed!

To use the TNC Emulation feature in MixW, you now must install a serial port bridge. There are several commercial products (costing mega-bucks), and if you have any of them installed on you computer you may use those instead of one provided my the MixW team. A "serial port bridge" is effectivly a software "null modem" cable. It connects two COM ports together using software, so no hardware solution is needed. The reason why you can't connect two programs to the same COM port is because only one program can have ownership of a COM port at a time; take your nearest CSC major out to lunch to find out exactly how it works. If you don't want to install this software and have a lot of hardware serial ports, go ahead and use a null modem cable.

The MixW ComEmul driver does exactly as described in the previous paragraph. This driver is the "software null modem" cable described. This allows MixW to spit out data on a COM port and another program (DataDecoder, or really any other program, such as APRSPoint or HyperTerminal) to read the data on a different COM port. These instructions are for WindowsXP, but Windows2000 should be similar.

• Installing:
  1. Download the ComEmulDrv3.zip driver from the MixW website. Save it to the Desktop.
  2. Unzip it using the Extraction Wizard (in WindowsXP) or with a similar program in Windows2000. Extract all the files to a new folder on the Desktop.
  3. Open Start Settings Control Panel Add/Remove Hardware. The Add/Remove Hardware wizard will launch, helping you with the install process.
  4. Click at the welcome screen.
  5. Click on , and click
  6. Since you want to install new drivers, not remove old ones, click on at the bottom of the list, then click
  7. Select , and click
  8. Select from the menu and click
  9. Since you want to install the drivers from a known location, click on at the bottom right of the next screen. It dosen't matter what is in the two fields above.
  10. At the next screen, click . Select ComEmulDrv.inf from the Desktop folder you extracted it into.
  11. Click at the next screen where "MixW serial port bridge" is selected, and click again to begin the installation progress.
  12. Click on when Windows complains about the MixW serial port bridge not passing the Windows Logo testing.
  13. The computer will churn for a bit, then it will be finished. Click on . The Serial Port Bridge is now installed, but needs to be configure before it can be used. If you want to delete the zip folder and extracted folder on the desktop, you may do so at this time. However, I would suggest you keep the zip folder so that in the future if you have problems, you can reinstall the drivers without having to find them on the net.
• Configuring for MixW:
  1. Open Start Settings Control Panel System , and click on the Hardware tab.
  2. Click the button.
  3. Expand and double-click on . This will bring up the MixW serial port bridge Properties.
  4. Select the Properties tab.
  5. You will be presented with the MixW Serial Port Bridge Properties. This is where you will set up the serial port bridge. I recommend that you set Pair #1 to COM5 and COM6. What the Serial Port Bridge does is route any data on COM5 to COM6 and vice versa. Do not use any "real" COM port numbers, as that may cause problems when devices try to access the COM port. (This program may be a generic serial port bridge, and may work with any other serial data, not just originating from MixW. Can anybody verify this?)
     
  6. Reboot the machine. Yes, I know, but you must reboot for it to work. The serial port bridge is now installed.

Check out the TNC Emulation page on the MixW website for more information. To remove the drivers, select the Driver tab in the Properties dialog box and click "Uninstall" at the bottom of the window. If you are running two instances of MixW on two soundcards, you can go to "Pair #2" and select the COM port numbers.

1. Go to Start Programs MixW2 MixW2
2. On the first startup, the "Personal data" box should open. If it dosen't, go to Configure Personal data.
3. Enter you callsign and name. Optionally, enter QTH, Lat/Long (remember to use negative Longitude if you are in the US), State, and country. Click OK. It is important to put your callsign in the field, or every time you start up MixW it will ask you to do so.
4. To disable the Tip of the Day, uncheck the box in the lower left, then click Close.
5. To remove the 3 floating toolbars (because you won't need them for packet), deselect View CAT Bar, Tuning Indicator, World Map.
6. To set the AX.25 packet mode, select Mode Packet. A check should appear next to it.
7. Set the settings for the Packet mode by going to Mode Mode Settings.
   1. In the General tab, type your callsign into Incoming MyCalls, and check Emulate KISS TNC on TNC emulation port.
      
   2. In the Modem tab, select VHF 1200 baud (Standard, 1200/2200 Hz).
      
   3. The other tabs (Parameters, Beacon/Unproto, Monitor) are fine with their default settings.
8. To configure your soundcard, go to Configure Sound device settings. Select "Computer Soundcard" for Device.
   
9. To configure the TNC emulation, go to Configure TNC Emulation. Set the port to COM5. Since you already set up the MixW Serial Port Bridge, any data that MixW puts out on COM5 will be routed to COM6 (DataDecoder program) internally. DataDecoder requires 9600 baud 8N1, but if you're not using the DataDecoder program you can set these to any values that are good for your program. Make sure to uncheck the "Disable device" box.
   

There are two ways to connect your radio to the computer:

• The easy way:
  Use a 3.5mm (miniplug) audio cable to connect the "Speaker Out" port on the radio to the "Microphone In" port on the computer. This is easy but not ideal because all we're doing right now is recieving. It is very important that the volume level on the radio be turned way down, because if not the input to the computer will blow out. If that happens you must get a new soundcard. You won't be able to hear the chirps of the packet either, becaue most radios mute the internal speaker when something is plugged in to the speaker jack.


• The right way:
  Use the packet port on the radio. All modern radios have a packet port either on the back or the front. Look at the manual of the radio; the pinout of the jack is usually in the beginning. There is a "Standard" pinout; however, not all radios use the "standard pinout." Here is a diagram of what the cable should look like with a "standard" Packet jack:
  
  If you use a pre-built mini-din cable (highly recommended), such as a keyboard extension, there is a "standard" color scheme to the small wires inside. Ground is brown, and 1200 baud packet audio is yellow. If you want to build a 9600 baud cable, the wire color is orange. If you would like to learn how to use this PKT port more effectively, please see our PKT Port Breakout Box page. It is really easy to build, and you can transmit with it too!
  
  The easiest way to build the cable is to solder an audio jack on to a cable with a Mini-Din connector on one end. Don't try to solder a Mini-Din connector on to an audio cable; you will drive yourself nuts trying to solder to the small pins! One thing we do at N6CP is to never use the "ring" on the audio cable. We don't use the ring because in some situations, such as when connecting to a mono sound card or when using a mono cable, any signals on the ring can get shorted to ground. This is bad, becuase it might blow out part of the radio or computer. If the ring is not used, plugging in a stereo cable into a mono jack won't blow out your equipment.
  
  Label the outside of the cable with something like "PKT 1200 Baud" so that 3 years from now you will remember what this cable was made for.
  

Setting up the MixW audio levels is not really a big challenge.

• If you hooked up the radio to the computer "the easy way," then you must be really careful about putting too much audio into the computer and blowing out the soundcard. Turn the volume control on the radio and computer way down. Then turn the volume on the radio up a little, and turn the volume control on the computer up (accessible from Configure Input volume. . .). Adjust the input volume control by adjusting the slider on the computer.
• If you used "the right way" to hook the radio to the computer, then your life is much easier. The audio volume coming from the radio is fixed, so the only adjustment to make is in Configure Input volume. . . Don't worry if you must turn the input volume way down; here at N6CP the slider is only 5% from the bottom.
• Either way you used to hook up the radio to the computer, you should see the approximate picture when no signals are being recieved but the squelch is open:
  
  The waterfall display shows relative amplitude(different colors), frequency(going across), and time(scrolling down). Going from weakest to strongest signal, the colors are blue, green, yellow, orange, and red. Orange and red colors are too much audio for the soundcard, and you should reduce the input amplitude by turning down the volume on the radio and/or turning down the microphone input volume, which can be accessed from Configure Input volume. . . The scale across the top of the waterfall is in Hertz. If the scale is too big or too small, right click on the waterfall display and select "Zoom x1". Notice that you can clearly see the audio passband of the SSB detector in this picture, from about 400Hz to 3kHz.
• A good way to set the audio levels is to go to tune your radio the the national APRS frequency (144.390 MHz) and listen. There should be (almost) continuous traffic if you live in a populated area. The way we have set up MixW, the APRS packets should scroll across the waterfall display and the packet data should be decoded and be displayed in the window. This is a snapshot of what the window looks like decoding APRS with the squelch off:
  
  
  Snapshot of decoding APRS with squelch on:
  
  Notice that because the FM detector is used, you cannot see the edges of the audio passband.