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Title: POTS codecs, anyone? Post by: K2PG on March 30, 2006, 05:38:53 PM Could any of you computer guys help me to set up a POTS codec system? I can operate my NJ station by remote control, but the audio quality over the telephone line sounds like s--t, compared to the audio quality that I get when I operate the station locally. I would like to digitalize that audio, send the digital bitstream over the telco line, then convert it back to analog at the transmitter end.
Although broadcasters have been using such codecs for years for broadcasts from the field, the commercially available codecs are horribly expensive. Title: Re: POTS codecs, anyone? Post by: WBear2GCR on March 30, 2006, 11:24:07 PM Check into Echolink....
You might be able to use it directly, or mine some of the technology... similar to Skype in terms of the use of the computer... The usual method for broadcast has been to do it in analog, "shift" the audio up in frequency and then on the receive end downconvert back to "normal" audio... this seems to work. I think HLR uses some sort of box like this for his BCQ broadcash... the technology ought to be described on the web somewhere, I'd guess. _-_-WBear2GCR Title: Re: POTS codecs, anyone? Post by: W1DAN on March 31, 2006, 09:18:58 AM Hi:
A friend is using E-QSO and Skype to remotely run his HF station. When he is using Skype for SSB, I cannot tell he is on the internet. Audio quality is pretty good. 73 Dan W1DAN Title: Re: POTS codecs, anyone? Post by: W1EQX on April 01, 2006, 10:37:30 PM I would also recommend Skype. It's free and the audio quality is quite good. As with any VOIP systems the fidelity is determined by the codec used. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
In general, on typical broadband connections, Skype audio frequency response appears to run up to at least 7 kHz or so. On a POTS line fidelity will probably be less... Carmine W1EQX |