CB Radio Communications 101
byJeff "RHINO" BabineauCO,209th VFS DeltaHawks
Our squadron is dedicated to LAN flight simming. During the coarse of a weekend, things can get pretty hectic in the sim. Having mutually supporting missions allows us to really get into the meat of a flight sim. With the amount of humans assigned to different mission roles, effectively communicating with each other can get very difficult. Team play or H2H play is even more difficult as that whatever happens in your bandit reports or position reports is heard through out the room. When engaged, Having the ability to hear if you've damaged you opponent is very unrealistic. This significantly lessens the impact of what the game could offer. Other times the room can be filled with others trying to play different games. The solution was obvious. We had to find an intercom system.
Why not an Intercom?

In deciding on an intercom system we had a number of things to consider. There are many intercom systems available. Electronic equipment stores and even some department stores can offer intercom systems. The designs for intercoms can be found at the library. A dedicated intercom system offers great sound quality and a lack of RF interference. It also has many drawbacks. Intercom systems can cost many hundreds of dollars. This is lessened if you build one yourself but do you have the time OR the know how? Price versus channels is another drawback. As stated what we needed was something that would allow us to separate one mission or game from the next. A retail intercom system with multiple channels certainly gets very high in price. The biggest drawback is the lack of flexibility. when an intercom system is purchased or built. It is a fixed item. when others join the group, modifications must be made to the entire group. when your group gets large enough you will quickly exceed the capacity of the intercom to work effectively. I did not feel the intercom system would be appropriate as we are already soaking tons of money into this hobby. Having to spend hundreds of dollars for such A LIMITED system would not work for me.

Now we're talking.

Eventually the idea of CB radios took shape. What it offers is multiple channels. We can use 38 in our area. The CB's have 40 channels to select from but channel 9 is for emergency use ONLY and channel 17 is used by the local community for general use. Others are used as well but significantly less so. A CB can be purchased for around $35.00. Used CB's can be had for $15 dollars. I purchased an extra 23 channel CB for $5 and it works great. Sound quality is mediocre but have you heard any military radios? We also have to use a PTT (Push to talk) switch. At this point it starts to sound and FEEL very real. We found that any new member can be quickly adapted to the squadron. No one modifies their system. He is the only one that spends any money. Another drawback was the necessity for a power supply at an additional $20-50. Most of us had power supplies laying around but unless they were well built for 12V DC, gave us a hum in our system. The antenna was the major drawback. A regular antenna was usually too powerful and would sometimes send random keyboard commands if the system was improperly shielded or located too close to your system. We found that removing the top of a two piece antennae helped. We tried removing the antennae but ALL CB's are subject to damage if you do that. We tried just a dummy load but we could not broadcast across the room with that. Eventually we used a modified dummy load/antenna set up. We also highly recommend the use of a pair of headphones with large cups. These work much better to isolate outside noises. I made a headset from garage sale headphones for $7.00! The other advantage is that extra CB's or a CB frequency scanner can be purchased to operate an AWACS station or actually record your flights. We have 2 CB's plugged to a boom box to record all our flights. It makes for great beer drinking background after the fly-in.

Why CB's?

This setup is also now used by the 555th in Oregon. In September of 1995, out two squadrons and a few other pilots got together for a West Coast LAN meet. We were able to assign TDY (temporary duty) positions as we all had CB's. The CB portion went off without a hitch. We then recorded the flights for our 2V2 competitions. The stress and virtual-realism was unbelievable. This epitomizes the flexibility and expandability of this setup.

Let's get real.

What about talking on the mic? Almost none of us do this. Usually only the new guys or those without the technical knowledge or time to modify their system. All of us have some time of PTT switch mounted on the throttles. The throttle mounted PTT switch is used in REAL aircraft. We could have purchased voice actuated but we did not feel it was as realistic and it was much more money. Some have their PTT switches mounted on the inside of their throttle. Others have them affixed to the outside. We do have one guy that made a knee switch! On my setup I have a TQS with the comms switch (duh!) wired to a relay. This relay connects to TWO CB's so that I can have a flight channel and a command frequency to monitor. The REAL f-16 has a 4 way comms switch but I know that it has only two radios, a VHF and UHF. I don't know what the other positions are used for in the block 50. The block 10 had only a two way. This allows me effortless comms. I push down to talk to my flight, I pull up to talk to other flights. I took the wires that were on the comms switch and mounted 4 buttons on the base of my TQS so that I could still have those 4 switches available. I guess sometime I'll have 4 radios and talk to everyone, including the truckers. The easiest way to make a throttle mounted PTT switch and mic setup is to modify the mic that came with the CB. The connection to the mic can be lengthened and male and female connectors placed so that you can unplug your headset. The switch is then mounted on to the throttle.

CB Radio Communication

Using a hand held mic in the middle of a furball is difficult if not fatal. Most of the Delta Hawks have headset mounted boom mics. Some are home made and some are store bought (Radio Shack has a nice stereo headset with boom mic setup for about $60). To hook up a boom mic, you need to cut open the CB hand held mic unit and connect up to the mic wires( remove the stock mic, you may use this for a homemade boom mic unit). The hardest part is locating your PTT (Push To Talk) switch in an easily accessible spot. We have varied setups from cutting into TQS throttles and mounting switches internally to creative hand held mic carving and judicious use of a hot glue gun. Your best bet is to come to a meet and see what each of us has already done.

Making a Headset.

Many members of the 209th VFS Delta Hawks use an Optimus Pro50MX headset with boom microphone from Radio Shack, these cost about $60. You can build your own for cheaper if you wish.

Parts needed.

  • Isolation headphones and the mic from your CB.
  • 1/8 " Male STEREO Jack.
  • 2- 1/8" male MONO jacks.
  • 1/8" female STEREO plug.
  • Appropriate sized stereo plug for you headphones. (1/4" stereo or 1/8" stereo)
  • 6 feet, 3 conductor cable.
  • 2 feet 1 conductor shielded cable
  • 2 feet flexible 14 gauge wire.
  • VERY small sheet metal screw.
Open mic up. Cut off the mic. Make sure you leave ample wire on the mic to allow soldering later. Make a bracket from some flexible but stiff wire. (A coat hanger works well for this). Use the sheet metal screw to attach one end to the headset (make a tight loop to put the screw through). Cut and adjust bracket to place mic just in front of your mouth. Solder enough wire to the mic to reach from the end of your "boom" to your CB with ample slack. Connect the exact same wires from the mono jack to the connections you made for the mono plug to the PTT switch.

Cut 1 foot of cable off. Ensure you slip the covers on the wires before you make connections. Strip 1/8" off all ends. (4 ends now). Using the long wire, connect 1 cable to tip end of stereo plug. Connect another end to the ring lug. Connect the third ground or shield to the shield of the plug. Do this on both stereo plug and jack. Using the 1 ft., coordinate and connect the appropriate colored wires the headphone jack. On the other end, cut off the shield wire and connect the other tip and ring wires to the tip and shield of the mono plug. Solder all connections and screw covers on. Plug the 5 foot wire into your sound card speaker jack. Plug the mono end in you CB EXT. speaker jack. Plug you headphones in.Using the Radio shack headset all you need to do is make a connector from the point on your PTT switch to a female 1/8" mono plug. Connect the mic to the end.

Connections for CB and Game Sound

Here is the diagram for getting CB sound in both sides of a headset without losing stereo game sound. All of the required parts are available at your local electronics store for less than $10.00 total.

To get CB Radio sound in both sides of a stereo HeadSet WITHOUT losing stereo game sound. Connect both wires from a mono external speaker jack to the "HOT" leads on a stereo jack. 
The tip and the secondary connections are used. The outer ring or "GROUND" lead is not used. Plug this adapter into a stereo "Y" adapter. Plug your headset into the other female side of the stereo "Y" connector and then plug the "Y" connector into the external speaker jack on your sound card. Due to space constraints, you may need to get a stereo extension cable, male to female, to go from your sound card to the "Y" connector.

Above is a store bought version. It also uses a 6' Stereo Male to Female extension to go from the sound card to the male end of the "Y" connector.

CB Short-range Antenna
Parts needed.
  • PL259 antenna connector
  • 10 feet of RG58 cable
  • 50 ohm 5 watt resistor.
Cut 1 foot of wire. Strip ends. Connect the antennas jack to one end. Solder the shield cable to one end of the resistor. Solder the center cable to the other end. This now provides 50 ohms of resistance. Strip about 4 inches on one end of the remaining 9 ft of cable. Solder the shield to the same end as the resistor with shield. Solder the cable end to the other side of the resistor with the cable end. Strip 1 inch of cable from the other end of the 9 ft. cable. Plug in antenna and run the cable anywhere. 
Solder one end of a 50 ohm, 5 or 10 watt resistor to the core wire of a 10 foot length of RG-58 COAX cable.
Solder the other end of the resistor to the shielding wire of the cable. (Strip the outer insulation as far back as
necessary to lay the resistor along the wire). Solder the other end of the core wire to the center tip of a PL-259
CB connector, Solder the outer shield wire to the outer casing of the connector.
PTT (Push To Talk) Switch

The PTT switch is made easiest by mounting your existing PTT switch from the CB on the throttle with hot glue. As stated before there are many ways to do this. It is your call. (We will be posting photos of many of our setups in the future.)

The multi-channel setup is rather difficult to make or explain. It requires a 12V 4 pole relay to activate 2 CB's and another to activate CB 3 and 4.If you want ME to build you a set up I will. We can negotiate the cost depending on what type of setup you want.

If you have any questions, e-mail Rhino at rhino@deltahawks.org

Copyright 2000 Jeff "RHINO" Babineau  ~209th VFS Delta Hawks~