interfacing details
when using the audio modem option, in a very silent environment, even placing your iphone's built-in microphone close to the transceiver's speaker will let you receive some packets. for best results though, connect your device's microphone-in port to your transceiver's audio or data-out port and vice versa.
the iphone's microphone-in and audio-out ports are available at the 4 conductor 3.5mm connector located at the top of the device. you can buy an appropriate adapter or easily build your own (tip: left out, ring 1: right out, ring 2: ground, sleeve: mic in). when connecting your iphone to your transceiver, also consider buying or building a "sound card interface", in order to isolate the path between the radio and the device and to be able to control the volume of the audio channels. such interface schematics can be found in amateur radio handbooks, radio manuals or the internet (e.g. check out
http://www.foxdelta.com). for sending data, as the iphone lacks an extra control port to provide a ptt signal, you should use an interface that automatically triggers ptt on available audio, or a transceiver that provides such a feature automatically. for instance, the yaesu ft-897d will automatically transmit when audio is available at the front mic input, when the "vox" feature is enabled.
这是接口部分的英文说明，说需要打开vox控制发射。
请看附图，注意最下面的audio modem 它可以打开transmit项目，我打开时就会听到一声调制声，这两天购买插接线，把它跟对讲机接起来，然后再给大家上报告。
如果可以的话，其实买个touch4 就可以用了，平常听歌，出去了配个3g路由可以上网。还能跟对讲机连起来。
