VOX Type PC to Radio Interface for Internet Link

The usual two meter radio communication is very limited when talking about coverage distance. This is due to the fact that at VHF frequencies and beyond, radio propagation is likely on line of sight. The higher your antenna is, the greater the distance it will cover. Nowadays technology has gone far; with the aid of internet communication thru VOIP, voice communication brings the world closer together. To cope with the advancement of technology, amateurs able to communicate worldwide thru their radios but not with the use of a huge and bulky HF transceivers, instead they were able to use the internet technology to hook up their radios to the internet. Available commercial interface unit cost so much that putting up a server is difficult.

 

This simple PC to radio interface project functions as a voice activated switch that will enable the audio from the radio to be retransmitted to the internet and vice versa with the use of a PC. The connecting wires must be a shielded type to avoid stray rf pick-up that might affect interface functionality. Internal power supply unit is needed especially when a portable transceiver is used while this can be eliminated if a mobile base transceiver is available since the 8 volts supply can be taken directly from the microphone input connector. The software for this project is the SKYPE because it can be downloaded for free on the internet. Implementations of this project can be a server, station identifier or to link several repeaters all over the world.  ---73 de hevir

Attachment: vox_type_server_interface.jpg

Switching Power Supply Modification

Most industrial equipments today uses switching type power supply in replace for the conventional linear power supply because of its efficiency and savings on electricity. Aside from its efficiency, switching power supply are lighter in terms of its current per pound ratio, its no wonder why all computer’s CPU are powered by a single switching power supply capable of delivering high current at the rated voltages.
In this project, it uses a switching power supply salvaged from old CPU. Before finding a second hand switching power supply, ensure that the 12 volts rating has a total current above 15 amps so that it will handle most mobile transceiver with a power output range of 50 watts.
Modification starts by removing the unwanted wires from the switching power supply. Unsolder all the colored wires except for the yellow (+12V), red (+5V), green (power enable), and the black (ground). You can attach binding posts at the external casing for the 12 volts DC output (yellow and black). Another binding post for the 5 volts DC output (red and black). A single SPST switch can be included for the POWER_ON (green and black). Overall modifications can be finished within an hour so there should be problem in building this project. ---73 de hevir