The Icarus Instruments EXTenna Switch is a small device installed in an aircraft that permits an existing VHF comm antenna to be used with any handheld VHF radio. This greatly extends the range and readability of a battery powered handheld radio compared to the normal “rubber ducky” antenna that has very limited range when used inside an aircraft cockpit. The EXTenna Switch eliminates the need to install a dedicated backup VHF comm antenna which is both expensive and adds drag to the airframe.
Installation
The EXTenna Switch is easily panel mounted (P/N EXTSW-1) by simply drilling three small holes (precision steel drilling template supplied) and applying a supplied label, or it can be installed in a pre-existing 2.25” clock hole (P/N EXTSW-2). It has two BNC connectors on the back side. One labelled TX connects to an existing VHF comm radio’s antenna connector (normally Comm 2) using a BNC jumper cable (not supplied). The other, labeled ANT, connects to the VHF comm antenna serving the same radio using the existing antenna cable that was previously connected to the radio. Installation can be accomplished by using Minor Alteration FAA guidance as the EXTenna Switch is a small, non-powered, passive device that weighs only two ounces.
Use
The default condition is that the comm radio is directly connected to the existing comm antenna through the EXTenna Switch. When the pilot needs to use the handheld radio, a supplied 4ft cable is attached to the handheld radio’s BNC RF jack at one end, and its 3.5mm connector is plugged into the jack on the EXTenna Switch. This disconnects the normal comm radio from its antenna and connects it to the handheld radio. EXTenna allows effective use of a handheld radio in emergency situations such as avionics or electrical failure, or for pre-start Clearance Delivery or Ground Control communications. Radio, ICS, headset, or PTT component failure could all result in the needed use of a backup handheld radio and EXTenna ensures effective, affordable, reliable, radio range and readability when that happens.
