For the last few years Amateur Radio enthusiasts have connected cellular Bluetooth headsets to transceivers using the Jabra
A210 or a device called TalkSafe. However, at the inception of this article in the fall of 2011, this hardware has been
discontinued and is hard to find. While some may question the utility of such a device, the idea is intriguing and useful on
three levels. First, there have been many occasions during contests where I am operating two or more radios and hand turning
antennas. The capability to monitor the band or conduct QSOs while away from the radio would come in handy. Second, the ability
to have a hands-free QSO while operating a vehicle. And third, the prospect of adding another RF transmission link (complete
with a transmit/receive antenna) into the normal radio communications process should appeal to most hams. The Radio Adapter
resides at the transceiver with its audio input connected to the transceiver audio output, and its audio output connected to the transceiver microphone connector. Pushbuttons control volume and Bluetooth connections.
Rev. 1: Some of the components are now only available in large quantities. Therefore, the parts list was revised to show
replacements for the affected components (Part List Rev. 1). Please note that the pictures on this page reflect the prototype
unit. Several PCB and component changes have been made to correct erroneous vendor info and add features. If you have a newer BT module with PowerSw firmware, you will need to either make revisions to the pc board (PCB Mods), or load new firmware. The
firmware versions are available on the KcWirefree downloads page. Follow the USB procedure in the Firmware Upgrade Guide and
download the kcAudioGateway v6.5 build 1 (PowerBtn), KC-6012. The new firmware circuit changes are reflected in ExpressPCB Files R1.
Due to changes in module firmare, I recommnd using Rev. 2 for new construction. This includes Rev. 2 of the Drawings, Parts List, Schematic, and PC Board layouts ("BT K-6112 R2.pcb" or "BT K-6112 R2 MiniBoard".pcb). The ExpressPCB MiniBoard Service
costs less but the PC Board must be cut to size by the user.
Rev. 2: N5IB has revised the original circuit to include new firmware improvements in the Bluetooth module. This circuit supports KCWirefree Audio Gateway firmware rev 6.5.2 and later, and includes a PTT function. I have incorporated all of his
modications into Rev 2, except for the power switch, S4. Also, all components are thru hole except for one SMT inductor and the Bluetooth module M1. Thanks to N5IB for his excellent work!
