The purpose of the N7BHC Advanced Capability Beacon is to explore extreme range trans-oceanic propagation between the East Coast of the USA and Europe / Africa. Tropospheric Ducting is the primary propagation mode being studied, but the system will provide a strong reliable signal suitable for reception and exploration of different propagation modes.
This beacon is still being assembled. Deployment is planned for the spring of 2009.
The N7BHC Advanced Capability Beacon is much more than a simple fixed design beacon with a single mode. It is in essence a PC controlled station with remote control and operation capability. The local computer provides allows autonomous operation most of the time. As it is remotely accessed over a broadband connection, different modulation modes can be selected. New modes can be added as they are developed. Remote control also allows for remote operation on the air using digital and voice modes. The local PC essentially controls the radio and modulation, and remote control is performed by another PC running VNC. Voice operation is accomplished with Skype audio. Telemetry is include so the beacon status and health can be remotely monitored.
The radio is a Kenwood TS-790A 2m/70cm all mode radio. 144 MHz is the primary band, and a 300 watt amplifier boosts the transmit signal power. The beacon operates at 100 watts output in beacon mode, but full power can be selected when in remote control mode. A 100 watt 70cm amplifier is planned for the future.
The 2m antenna will be a vertical stack of eight 5-element custom designed yagis. The large vertical array provides an E-plane -3dB beamwidth of 55º with an H-plane -3dB beamwidth of only 4.5º. The wide E-plane beamwidth illuminates a wide target area from Ireland to Senegal without needing to be rotated. The planned 70cm array is eight 12-element yagis with -3dB beamwidths of 35º and 2.5º on the E and H planes respectively.