A word of sound advice. There are "SOME" pilots and builders out there who have decided to save money by not buying and installing a radio system in their plane. This in itself is a "DANGEROUS" decision for more reasons than I would care to list. However, the most important reason for a radio system is during take off and landing procedures. Many small uncontrolled airports do have... fairly moderate pattern traffic at times. Without a radio to announce your intentions and to hear other aircraft, you may place yourself, your passenger, and those in other aircraft operating near you in "Harm's Way". The extreme danger of being injured, or worse... killed in a ground or mid-air collision is increased without stating your intentions or hearing those of other aircraft operating or flying in your close proximity. A working radio is a good way to help ensure aircraft separation and safety.

The drawing to the left shows a radio system with intercom for two people in a Challenger II or similar aircraft with dual seats.

To the right, the diagram is for a Challenger I or single pilot aircraft radio system without intercom.

A "coil patch cord", such as shown on the right, is used in a Challenger I, single place to connect the headset and PTT buton to the radio.

The following installation is to mount the Intercom Controller on the front side of the front seat down tubes. However, for a taller pilot, it would be far better to install the controller on the rear side of the down tubes.

Using a piece of scrap aluminum sheeting, measure, cut and rivet the aluminum plate to the front seat down tubes.

By opening the intercom casing, you can drill through the intercom back panel and aluminum sheeting to mount and rivet the intercom controller to the sheeting. This location is suitable for ease of adjusting the volume controls by either pilot or passenger.

A Comtronics, Dual-Com II intercom is being installed. The front of the intercom is the volume control buttons (outside) for the headsets. Next is the connector receptacle for plugging your headsets into the intercom. The toggle switch (center) is used to toggle between two radios, if you use two.

On the back, looking bottom to top, we can see the power (black & red) wire. Next is a mini-jack for music input, like from a CD player. Then we see the PTT button (Push To Talk). Finally we see Radio #1 and Radio #2 inputs.

Other locations for the intercom controller would be under the front seat, and facing forward to allow the pilot to adjust the volume controls, as well as, the ON/OFF button. A right-hand, side mounting also offers decent ease of adjustment to the unit's control panel by the pilot. However, both locations make it cumbersome to adjust the intercom controls, as well as, dealing with the rear headset cord in these locations.

A standard 18 inch aircraft rod type antenna is show on the left. About 118-136 MHz. Wt. 8 oz. BNC termination. It is supplied with weather sealing rubber pad and mounting hardware. This type of antenna is usually mounted on the crown of the front gap cover for optimum performance.

In the left photo is shown the popular Miracle Air Whip Antenna. Installation of the Miracle Air Whip Antenna is a snap. It is designed to be attached to the inside of the fiberglass nose. You can use hot glue, silicone or duct tape to install it. The Miracle Air Whip is a full half-wave dipole antenna which allows it to be pre-tuned for maximum radiation during its manufacturing process. It operates completely independent of ground planes or wires. It is also a lower cost alternative to the standard communications antenna like the one mentioned above.