GN Netcom GN-9350e Wireless Headset for your HF Radio After having so much success with the Jabra A-210 and VXI Bluetooth Headset, I decided to experiment with a different wireless headset, made by GN Netcom. Although these headsets are normally expensive, they can sometimes be found on EBay for a reasonable price (~$100 USD). The GN-9350e has several advantages over the VXI Bluetooth system. It includes both the headset and mating base unit; has a much greater range (~300 Feet), longer headset battery life, and the headset recharging cradle is part of the base unit, which is powered by a wall wart. When you are not using the headset, you simply place it in the cradle on top of the base unit, which keeps it charged, and ready for your next use. Interfacing it to your HF radio is also very simple. There is a 4-Pin modular connector on the back of the GN-9350e base unit that accepts a 4P4C handset modular connector. This connector is smaller than other RJ connectors, and sometimes hard to find. They are used with telephone handsets. You will need to locate one of these for this project. The inner two conductors in the 4P4C connector connect to your radio's RX audio, and the two outer wires connect to your radio's radio's Mic input. I wired my 4P4C connector starting on one side as Mic Hi - Ground - RX Audio - Mic Ground. This places a ground adjacent to each "hot" conductor, and separates the RX audio and Mic Hi from each other. I used a 6 foot length of 4-conductor flat telephone cable, with a crimped 4P4C modular connector at one end, and a standard 8-pin microphone connector at the other end. If you are using an ICOM radio that has the standard 8-Pin Mic connector, the inner two conductors of the flat cable connect between pin-8 (RX audio) & pin-6 (Ground). The outer two conductors connect between pin-1 (Mic Hi) & pin-7 (Mic Ground). When viewing the 4P4C Modular connector from the "flat" side (the opposite side from the retainer tang (Yellow Wire on Top). Most 4-conductor flat telephone wire 1 / 6
should follow the color scheme below. See Picture #2 Below. ICOM Microphone Pin 1 (MIC HI) ----------------------------------> Yellow wire in Modular ICOM Microphone Pin 8 (RX AUDIO HI) -------------------------> Green Wire in Modular ICOM Microphone Pin 6 (RX AUDIO LO & GND) ------------------------------> Red wire in Modular ICOM Microphone Pin 7 (MIC Ground) ---------------------------> Black wire in Modular Most other equipment manufacturers do not provide RX audio at the Mic connector, so you will need to "break out" the RX audio leads and obtain the audio from the headphones jack. You might also be able to interface the 9350's base unit with the accessory audio connections on the back of your radio, but be cautious since VOX operation might only be permitted thru the front panel Mic connector. The 8-pin Mic connectors are readily available at most RadioShack stores. Should you experience any RF feedback, wind several turns of the flat telephone cable around a snap-on ferrite bead near the back of the 9350's base unit. Recently, I connected the supplied Mini-USB cable between the USB port on my GN-9350e headset base unit and a spare USB port on my PC. This allows the GN-9350e to be used with your computer programs like "SKYPE" and other programs requiring an audio interface. There are flat buttons on either side of the front part of the 9350's base unit. Pressing the right button selects the radio audio interface, and pressing the left button selects the USB audio port connected to your PC. It makes it easy to switch back 2 / 6
and forth between the radio and PC. GN-9350e Base Unit (Cover Removed) showing the wall wart power connection, 4P4C modular connector & cable going towards the rig, and Mini-USB connection going to my PC.. 3 / 6
Closeup of Icom Mic Cable GN-9350e Front View with Headset in charging cradle/base Unit 4 / 6
I used the following settings on the 9350e Base Unit: Clear Dial Tone Switch = "A" TX Volume Setting = 7/12 Hook Switch Select = MSH Range/Power = Normal Sound Mode = Normal 5 / 6
Protection Level = 1 That is pretty much all there is to adapting this headset for use with your rig. Good Luck, Frank - K7SFN 6 / 6