Here's the video of the ZL3IN c2qso.sh contact. Remember, this is just raw UDP packets over the internet, with no error correction, and you're hearing the Codec2 audio just as it was transmitted in the conversation.
Yes, Zilvis, the audio was duplex. With my shell script, if both sides keep 'transmit' on, it will operate duplex.
While codec2 might be useful for general Internet comms in certain circumstances, in general I think the higher bandwidth codecs are a better idea for Echolink, etc. For hams, codec2 will shine in digital voice systems similar to D-star.
The AA2TX parasitic lindenblad, which was published in Feb 2010 QST (and has been available online for some time), is proving to be an enjoyable project. I have modified some components because I could not find them here in Atlantic Canada. The #8 aluminum wire for the passive elements is not in our big box stores (different wiring regulations?), and the PVC ferrules require a special order, at least at this point in the year, when no sane person would be installing eavestroughing. So I made do with what I had, and the results are encouraging.
The TH-D72 USB port is configured as a CDC device, using the CP2102 USB UART bridge. On Windows, presumably you should use the drivers provided by Kenwood. I accessed the port on my Ubunutu 10.04 desktop just by using /dev/tty.USB0, which popped open when I connected the device. CP2102 support evidently is built into recent kernels. Looking around, it seems that MacOS support is more dicey, so I'll probably experiment with it using a linux box or a virtual linux machine on my MacBook. For the person like me, who is hoping to connect this to an embedded device, there's some particularly bad news: this chip doesn't communicate using the plain CDC-ACM; I'm told it has a proprietary communication system to the host. The best bet is to port the software from the linux kernel, alas.
I just finished listening to the morse code beacon of a new amateur satellite, XW-1 , made by amateurs in China and launched by the Chinese government. This is going to be an excellent communications satellite. It has a 1200 km high orbit, meaning that it sees more of the earth than a lower satellite, and therefore people at a greater distance can talk to each other through it. Also, judging by the beacon, it provides a very steady signal, not terribly subject to fades.
Great video! And audio too! Was that full duplex comms?
ReplyDeleteAlmost half step to the next Echolink incarnation (multiplatform, oss) hi
Best 73! Zilvis
Yes, Zilvis, the audio was duplex. With my shell script, if both sides keep 'transmit' on, it will operate duplex.
ReplyDeleteWhile codec2 might be useful for general Internet comms in certain circumstances, in general I think the higher bandwidth codecs are a better idea for Echolink, etc. For hams, codec2 will shine in digital voice systems similar to D-star.